Stephen J. Simpson

Resource distribution mediates synchronization of physiological rhythms in locust groups

Publisher: The Royal Society

Date: 29-03-2006

DOI: 10.1098/RSPB.2006.3471

Abstract: Synchronized behaviour is common in animal groups. In ant colonies, synchronization occurs because active ants stimulate their neighbours to activity. We use oscillator theory to explain how stimulation from active neighbours synchronizes activity in groups of solitarious locusts via entrainment of internal physiological rhythms. We also show that the spatial distribution of food resources controls coupling between in idual locusts and the emergence of synchronized activity. In locusts ( Schistocerca gregaria ), in idual schedules of activity and quiescence arise from an irregular physiological oscillation in feeding excitation (i.e. hunger). We show that contact with an active neighbour increases the probability that a locust becomes active. This entrained activity decreases the time until the locust feeds, shifting the phase of its hunger oscillation. The locusts' internal physiological rhythms are thus brought into alignment and their activity becomes synchronized. When food resources are clumped, contact with active locusts increases, and this increase in the strength of coupling between in iduals leads to greater synchronization of behaviour. Activity synchronization might have functional significance in inhibiting swarming when resources are dispersed and accelerating it in more favourable clumped environments.

Evidence for Protein Leverage in Children and Adolescents with Obesity

Publisher: Wiley

Date: 06-03-2020

DOI: 10.1002/OBY.22755

Multidimensional associations between nutrient intake and healthy ageing in humans

Publisher: Springer Science and Business Media LLC

Date: 09-2022

DOI: 10.1186/S12915-022-01395-Z

Abstract: Little is known about how normal variation in dietary patterns in humans affects the ageing process. To date, most analyses of the problem have used a unidimensional paradigm, being concerned with the effects of a single nutrient on a single outcome. Perhaps then, our ability to understand the problem has been complicated by the fact that both nutrition and the physiology of ageing are highly complex and multidimensional, involving a high number of functional interactions. Here we apply the multidimensional geometric framework for nutrition to data on biological ageing from 1560 older adults followed over four years to assess on a large-scale how nutrient intake associates with the ageing process. Ageing and age-related loss of homeostasis (physiological dysregulation) were quantified via the integration of blood biomarkers. The effects of diet were modelled using the geometric framework for nutrition, applied to macronutrients and 19 micronutrients/nutrient subclasses. We observed four broad patterns: (1) The optimal level of nutrient intake was dependent on the ageing metric used. Elevated protein intake improved/depressed some ageing parameters, whereas elevated carbohydrate levels improved/depressed others (2) There were non-linearities where intermediate levels of nutrients performed well for many outcomes (i.e. arguing against a simple more/less is better perspective) (3) There is broad tolerance for nutrient intake patterns that don’t deviate too much from norms (‘homeostatic plateaus’). (4) Optimal levels of one nutrient often depend on levels of another (e.g. vitamin E and vitamin C). Simpler linear/univariate analytical approaches are insufficient to capture such associations. We present an interactive tool to explore the results in the high-dimensional nutritional space. Using multidimensional modelling techniques to test the effects of nutrient intake on physiological dysregulation in an aged population, we identified key patterns of specific nutrients associated with minimal biological ageing. Our approach presents a roadmap for future studies to explore the full complexity of the nutrition-ageing landscape.

Coping with crowds: Density-dependent disease resistance in desert locusts

Publisher: Proceedings of the National Academy of Sciences

Date: 16-04-2002

DOI: 10.1073/PNAS.082461999

Abstract: Parasite transmission generally exhibits some form of positive density dependence. Thus, as population density increases, so too does the per capita risk of becoming infected. Under such circumstances, natural selection should favor in iduals that use cues associated with population density to determine the optimal allocation of resources to disease resistance mechanisms. As a consequence, in iduals experiencing crowded conditions are predicted to be more resistant to parasites and pathogens than those experiencing low-density conditions. This phenomenon (termed “density-dependent prophylaxis”) [Wilson, K. & Reeson, A. F. (1998) Ecol. Entomol. 23, 100–101] is predicted to be particularly prevalent in outbreak pest species and in species exhibiting density-dependent phase polyphenism, such as the desert locust, Schistocerca gregaria . Here we show that, as predicted, desert locusts reared under crowded conditions are significantly more resistant than solitary locusts to the entomopathogenic fungus, Metarhizium anisopliae var. acridum , a key natural disease of acridids and an important agent in locust and grasshopper biocontrol. Moreover, enhanced pathogen resistance in crowded locusts is associated with elevated antimicrobial activity, but not with any difference in thermal preferences or behavioral fever response. These results have implications for understanding the development and biocontrol of locust plagues.

Evaluation of potential reference genes for reverse transcription-qPCR studies of physiological responses in Drosophila melanogaster

Publisher: Elsevier BV

Date: 06-2011

DOI: 10.1016/J.JINSPHYS.2011.03.014

Abstract: Drosophila melanogaster is one of the most important genetic models and techniques such as reverse transcription quantitative real-time PCR (RT-qPCR) are being employed extensively for deciphering the genetics basis of physiological functions. In RT-qPCR, the expression levels of target genes are estimated on the basis of endogenous controls. The purpose of these reference genes is to control for variations in RNA quantity and quality. Although determination of suitable reference genes is essential to RT-qPCR studies, reports on the evaluation of reference genes in D. melanogaster studies are lacking. We analyzed the expression levels of seven candidate reference genes (Actin, EF1, Mnf, Rps20, Rpl32, Tubulin and 18S) in flies that were injured, heat-stressed, or fed different diets. Statistical analyses of variation were determined using three established software programs for reference gene selection, geNorm, NormFinder and BestKeeper. Best-ranked references genes differed across the treatments. Normalization candidacy of the selected candidate reference genes was supported by an analysis of gene expression values obtained from microarray datasets available online. The differences between the experimental treatments suggest that assessing the stability of reference gene expression patterns, determining candidates and testing their suitability is required for each experimental investigation.

Tissue-specific immune gene expression in the migratory locust, Locusta Migratoria

Publisher: MDPI AG

Date: 16-04-2015

DOI: 10.3390/INSECTS6020368

Locusts use dynamic thermoregulatory behaviour to optimize nutritional outcomes

Publisher: The Royal Society

Date: 02-02-2011

DOI: 10.1098/RSPB.2010.2675

Abstract: Because key nutritional processes differ in their thermal optima, ectotherms may use temperature selection to optimize performance in changing nutritional environments. Such behaviour would be especially advantageous to small terrestrial animals, which have low thermal inertia and often have access to a wide range of environmental temperatures over small distances. Using the locust, Locusta migratoria , we have demonstrated a direct link between nutritional state and thermoregulatory behaviour. When faced with chronic restrictions to the supply of nutrients, locusts selected increasingly lower temperatures within a gradient, thereby maximizing nutrient use efficiency at the cost of slower growth. Over the shorter term, when locusts were unable to find a meal in the normal course of ad libitum feeding, they immediately adjusted their thermoregulatory behaviour, selecting a lower temperature at which assimilation efficiency was maximal. Thus, locusts use fine scale patterns of movement and temperature selection to adjust for reduced nutrient supply and thereby ameliorate associated life-history consequences.

Branched-chain amino acids impact health and lifespan indirectly via amino acid balance and appetite control

Publisher: Springer Science and Business Media LLC

Date: 29-04-2019

DOI: 10.1038/S42255-019-0059-2

Group foraging decisions in nutritionally differentiated environments

Publisher: Wiley

Date: 07-03-2016

DOI: 10.1111/1365-2435.12646

Amoeboid organism solves complex nutritional challenges

Publisher: Proceedings of the National Academy of Sciences

Date: 09-03-2010

DOI: 10.1073/PNAS.0912198107

Abstract: A fundamental question in nutritional biology is how distributed systems maintain an optimal supply of multiple nutrients essential for life and reproduction. In the case of animals, the nutritional requirements of the cells within the body are coordinated by the brain in neural and chemical dialogue with sensory systems and peripheral organs. At the level of an insect society, the requirements for the entire colony are met by the foraging efforts of a minority of workers responding to cues emanating from the brood. Both ex les involve components specialized to deal with nutrient supply and demand (brains and peripheral organs, foragers and brood). However, some of the most species-rich, largest, and ecologically significant heterotrophic organisms on earth, such as the vast mycelial networks of fungi, comprise distributed networks without specialized centers: How do these organisms coordinate the search for multiple nutrients? We address this question in the acellular slime mold Physarum polycephalum and show that this extraordinary organism can make complex nutritional decisions, despite lacking a coordination center and comprising only a single vast multinucleate cell. We show that a single slime mold is able to grow to contact patches of different nutrient quality in the precise proportions necessary to compose an optimal diet. That such organisms have the capacity to maintain the balance of carbon- and nitrogen-based nutrients by selective foraging has considerable implications not only for our understanding of nutrient balancing in distributed systems but for the functional ecology of soils, nutrient cycling, and carbon sequestration.

Maternal effects on phase characteristics in the desert locust, Schistocerca gregaria: A review of current understanding

Publisher: Elsevier BV

Date: 09-2007

DOI: 10.1016/J.JINSPHYS.2007.05.011

Abstract: Desert locusts demonstrate pronounced density-dependent polyphenism: a complex suite of traits shifts over the lifetime of an in idual in response to crowding or isolation. These changes also accumulate across generations through a maternal effect. Female desert locusts alter the developmental trajectory of their offspring in response to their own experience of crowding. The mother possesses a memory of both the recency and extent of crowding and shifts the phase state of her hatchlings accordingly. Extensive experimental work has shown that offspring behaviour is controlled by a low molecular weight, polar compound (or compounds) released from the mother's accessory glands. The chemical identity of this agent is not yet known.

Dietary protein increases T-cell-independent sIgA production through changes in gut microbiota-derived extracellular vesicles

Publisher: Springer Science and Business Media LLC

Date: 27-07-2022

DOI: 10.1038/S41467-022-31761-Y

Abstract: Secretory IgA is a key mucosal component ensuring host-microbiota mutualism. Here we use nutritional geometry modelling in mice fed 10 different macronutrient-defined, isocaloric diets, and identify dietary protein as the major driver of secretory IgA production. Protein-driven secretory IgA induction is not mediated by T-cell-dependent pathways or changes in gut microbiota composition. Instead, the microbiota of high protein fed mice produces significantly higher quantities of extracellular vesicles, compared to those of mice fed high-carbohydrate or high-fat diets. These extracellular vesicles activate Toll-like receptor 4 to increase the epithelial expression of IgA-inducing cytokine, APRIL, B cell chemokine, CCL28, and the IgA transporter, PIGR. We show that succinate, produced in high concentrations by microbiota of high protein fed animals, increases generation of reactive oxygen species by bacteria, which in turn promotes extracellular vesicles production. Here we establish a link between dietary macronutrient composition, gut microbial extracellular vesicles release and host secretory IgA response.

Hosts use altered macronutrient intake to circumvent parasite-induced reduction in fecundity

Publisher: Elsevier BV

Date: 2011

DOI: 10.1016/J.IJPARA.2010.06.007

Abstract: Explanations for the evolution of pathogen-induced fecundity reduction usually rely on a common principle: the trade-off between host longevity and reproduction. Recent advances in nutritional research have, however, challenged this assumption and shown that longevity and reproduction are not inextricably linked. In this study, we showed that beetles infected by cysticercoids of the tapeworm Hymenolepis diminuta increased their total food intake and, more particularly, their carbohydrate consumption compared with uninfected insects. This increased intake was only pronounced during the first 12 days p.i., when the parasite grows and develops into a mature metacestode. Despite consuming more nutrients, infected in iduals sustained lower levels of body lipid and were less efficient at converting ingested protein to body protein. However they demonstrated a capacity to compose a diet that sustained high levels of reproductive output unless confined to foods that were nutritionally dilute. We did not find any indication that macronutrient intakes had an effect on host pro-phenoloxidase activity however, phenoloxidase activity was significantly affected by protein intake. Our results showed that when offered nutritionally complementary diets, infected hosts do not systematically suffer a reduction in fecundity. Thus, in our view, the assumption that a reduction in host reproduction represents an adaptive response by the host or the parasite to ert resources away from reproduction toward other traits should be reassessed.

Dietary ratio of protein to carbohydrate induces plastic responses in the gastrointestinal tract of mice

Publisher: Springer Science and Business Media LLC

Date: 09-2010

DOI: 10.1007/S00360-009-0402-0

Abstract: Some vertebrates change the size of their digestive system in response to quantity and fibre content of ingested food, but the effects of dietary nutrients on gut structure remain poorly understood. Here we investigate how the protein to carbohydrate ratio of diets affects the mass of the gastrointestinal tract in mice. We fed 6-week-old male mice one of five isocaloric diets differing only in protein to carbohydrate ratio (the "no-choice" treatments), while a further four treatment groups received nutritionally complementary food pairings from which they could self-select a diet (the "choice" treatments). After 32 days, we measured the resulting dry mass of stomachs, intestines, caeca and colons. In the no-choice treatments, the stomachs were heavier in the mice fed diets containing more protein and less carbohydrate, indicating that larger stomachs may be needed for efficient digestion of the protein-rich food. In contrast, intestines, caeca and colons were heavier when diets contained more carbohydrates and less protein. This response may function to increase the digestive rate of carbohydrates when the dietary content of this macronutrient increases, but it may also indicate a compensatory response to increase amino acid uptake from a protein-deficient food. Mice in the choice treatments self-selected a diet with a protein to carbohydrate ratio of 0.46, and had gut dimensions similar to the expectation derived from no-choice treatments for this diet composition. Our results provide an ex le of plasticity in the differential allocation of resources to organ function, which is triggered by variation in resource quality.

Application of quorum response and information entropy to animal collective motion modeling

Publisher: Wiley

Date: 27-03-2016

DOI: 10.1002/CPLX.21772

Nutritional ecology beyond the individual: a conceptual framework for integrating nutrition and social interactions

Publisher: Wiley

Date: 14-01-2015

DOI: 10.1111/ELE.12406

Gut-derived acetate promotes B10 cells with antiinflammatory effects

Publisher: American Society for Clinical Investigation

Date: 08-04-2021

DOI: 10.1172/JCI.INSIGHT.144156

Dietary Protein to Carbohydrate Ratio and Caloric Restriction: Comparing Metabolic Outcomes in Mice

Publisher: Elsevier BV

Date: 06-2015

DOI: 10.1016/J.CELREP.2015.05.007

Effects of Prey Macronutrient Content on Body Composition and Nutrient Intake in a Web-Building Spider

Publisher: Public Library of Science (PLoS)

Date: 09-06-2014

DOI: 10.1371/JOURNAL.PONE.0099165

Obesity and Male Reproduction; Placing the Western Diet in Context

Publisher: Frontiers Media SA

Date: 11-03-2021

DOI: 10.3389/FENDO.2021.622292

Abstract: There is mounting evidence that obesity has negative repercussions for reproductive physiology in males. Much of this evidence has accumulated from rodent studies employing diets high in fat and sugar (“high fat” or “western” diets). While excessive fats and carbohydrates have long been considered major determinants of diet induced obesity, a growing body of research suggests that the relationships between diet composition and obesity are more complex than originally thought, involving interactions between dietary macronutrients. However, rodent dietary models have yet to evolve to capture this, instead relying heavily on elevated levels of a single macronutrient. While this approach has highlighted important effects of obesity on male reproduction, it does not allow for interpretation of the complex, interacting effects of dietary protein, carbohydrate and fat. Further, the single nutrient approach limits the ability to draw conclusions about which diets best support reproductive function. Nutritional Geometry offers an alternative approach, assessing outcomes of interest over an extended range of dietary macronutrient compositions. This review explores the practical application of Nutritional Geometry to study the effects of dietary macronutrient balance on male reproduction, including experimental considerations specific to studies of diet and reproductive physiology. Finally, this review discusses the promising use of Nutritional Geometry in the development of evidence-based pre-conception nutritional guidance for men.

Are Glycans the Holy Grail for Biomarkers of Aging? (Comment on: Glycans Are a Novel Biomarker of Chronological and Biological Age by Kristic et al.)

Publisher: Oxford University Press (OUP)

Date: 10-12-2013

DOI: 10.1093/GERONA/GLT202

Abstract: Posttranslational modifications of circulating proteins such as immunoglobulins may prove to be important biomarkers of aging.

Dietary carbohydrate, particularly glucose, drives B cell lymphopoiesis and function

Publisher: Elsevier BV

Date: 08-2021

DOI: 10.1016/J.ISCI.2021.102835

Towards an integrated understanding of gut microbiota using insects as model systems

Publisher: Elsevier BV

Date: 10-2014

DOI: 10.1016/J.JINSPHYS.2014.05.016

Abstract: Metazoans form symbioses with microorganisms that synthesize essential nutritional compounds and increase their efficiency to digest and absorb nutrients. Despite the growing awareness that microbes within the gut play key roles in metabolism, health and development of metazoans, symbiotic relationships within the gut are far from fully understood. Insects, which generally harbor a lower microbial ersity than vertebrates, have recently emerged as potential model systems to study these interactions. In this review, we give a brief overview of the characteristics of the gut microbiota in insects in terms of low ersity but high variability at intra- and interspecific levels and we investigate some of the ecological and methodological factors that might explain such variability. We then emphasize how studies integrating an array of techniques and disciplines have the potential to provide new understanding of the biology of this micro eco-system.

Sex-specific fitness effects of nutrient intake on reproduction and lifespan

Publisher: Elsevier BV

Date: 07-2008

DOI: 10.1016/J.CUB.2008.06.059

Abstract: Diet affects both lifespan and reproduction [1-9], leading to the prediction that the contrasting reproductive strategies of the sexes should result in sex-specific effects of nutrition on fitness and longevity [6, 10] and favor different patterns of nutrient intake in males and females. However, males and females share most of their genome and intralocus sexual conflict may prevent sex-specific diet optimization. We show that both male and female longevity were maximized on a high-carbohydrate low-protein diet in field crickets Teleogryllus commodus, but male and female lifetime reproductive performances were maximized in markedly different parts of the nutrient intake landscape. Given a choice, crickets exhibited sex-specific dietary preference in the direction that increases reproductive performance, but this sexual dimorphism in preference was incomplete, with both sexes displaced from the optimum diet for lifetime reproduction. Sexes are, therefore, constrained in their ability to reach their sex-specific dietary optima by the shared biology of diet choice. Our data suggest that sex-specific selection has thus far failed fully to resolve intralocus sexual conflict over diet optimization. Such conflict may be an important factor linking nutrition and reproduction to lifespan and aging.

Locusts increase carbohydrate consumption to protect against a fungal biopesticide

Publisher: Elsevier BV

Date: 10-2014

DOI: 10.1016/J.JINSPHYS.2014.05.015

Abstract: There is growing evidence to suggest that hosts can alter their dietary intake to recoup the specific resources involved in mounting effective resistance against parasites and pathogens. We examined macronutrient ingestion and disease-resistance in the Australian plague locust (Chortoicetes terminifera), challenged with a fungal pathogen (Metarhizium acridum) under dietary regimes varying in their relative amounts of protein and digestible carbohydrate. Dietary protein influenced constitutive immune function to a greater extent than did carbohydrate, indicating higher protein costs of mounting an immune defence than carbohydrate or overall energy costs. However, it appears that increased immune function, as a result of greater protein ingestion, was not sufficient to protect locusts from fungal disease. We found that locusts restricted to diets high in protein (P) and low in carbohydrate (C) were more likely to die of a fungal infection than those restricted to diets with a low P:C ratio. We hypothesise that the fungus is more efficient at exploiting protein in the insect's haemolymph than the host is at producing immune effectors, tipping the balance in favour of the pathogen on high-protein diets. When allowed free-choice, survivors of a fungus-challenge chose a less-protein-rich diet than those succumbing to infection and those not challenged with fungus locusts. These results are contrary to previous studies on caterpillars in the genus Spodoptera challenged with bacterial and baculoviral pathogens, indicating that nutrient ingestion and pathogen resistance may be a complex interaction specific to different host species and disease agents.

Restriction of essential amino acids dictates the systemic metabolic response to dietary protein dilution

Publisher: Springer Science and Business Media LLC

Date: 09-06-2020

DOI: 10.1038/S41467-020-16568-Z

Abstract: Dietary protein dilution (DPD) promotes metabolic-remodelling and -health but the precise nutritional components driving this response remain elusive. Here, by mimicking amino acid (AA) supply from a casein-based diet, we demonstrate that restriction of dietary essential AA (EAA), but not non-EAA, drives the systemic metabolic response to total AA deprivation independent from dietary carbohydrate supply. Furthermore, systemic deprivation of threonine and tryptophan, independent of total AA supply, are both adequate and necessary to confer the systemic metabolic response to both diet, and genetic AA-transport loss, driven AA restriction. Dietary threonine restriction (DTR) retards the development of obesity-associated metabolic dysfunction. Liver-derived fibroblast growth factor 21 is required for the metabolic remodelling with DTR. Strikingly, hepatocyte-selective establishment of threonine biosynthetic capacity reverses the systemic metabolic response to DTR. Taken together, our studies of mice demonstrate that the restriction of EAA are sufficient and necessary to confer the systemic metabolic effects of DPD.

Adaptive Senectitude: The Prolongevity Effects of Aging

Publisher: Oxford University Press (OUP)

Date: 11-10-2010

DOI: 10.1093/GERONA/GLQ171

Abstract: In the past, it has been assumed that all the biological and medical changes that occur in old age are deleterious. It has therefore been concluded that treatment and prevention of such changes in old age should increase healthspan and delay death. However, accruing epidemiological and clinical trial evidence in older humans suggests that this is not the case. Some studies have shown that antioxidants and hormone supplements increase mortality, whereas high blood pressure, obesity, and metabolic syndrome are often associated with improved outcomes in very elderly people. Perhaps, some of these supposedly detrimental changes accompanying old age are in fact evolutionary adaptations to prolong life after reproduction in humans. Indeed, a form of reverse antagonistic pleiotropy or adaptive senectitude might be occurring. Some common biological and medical changes in old age might actually enhance longevity and represent novel targets for improving health in older people.

Locusts

Publisher: Elsevier BV

Date: 05-2008

DOI: 10.1016/J.CUB.2008.02.029

Macronutrient balancing in free‐ranging populations of moose

Publisher: Wiley

Date: 15-07-2021

DOI: 10.1002/ECE3.7909

Abstract: At northern latitudes, large spatial and temporal variation in the nutritional composition of available foods poses challenges to wild herbivores trying to satisfy their nutrient requirements. Studies conducted in mostly captive settings have shown that animals from a variety of taxonomic groups deal with this challenge by adjusting the amounts and proportions of available food combinations to achieve a target nutrient balance. In this study, we used proportions‐based nutritional geometry to analyze the nutritional composition of rumen s les collected in winter from 481 moose ( Alces alces ) in southern Sweden and examine whether free‐ranging moose show comparable patterns of nutrient balancing. Our main hypothesis was that wild moose actively regulate their rumen nutrient composition to offset ecologically imposed variation in the nutritional composition of available foods. To test this, we assessed the macronutritional composition (protein, carbohydrates, and lipids) of rumen contents and commonly eaten foods, including supplementary feed, across populations with contrasting winter diets, spanning an area of approximately 10,000 km 2 . Our results suggest that moose balanced the macronutrient composition of their rumen, with the rumen contents having consistently similar proportional relationship between protein and nonstructural carbohydrates, despite differences in available (and eaten) foods. Furthermore, we found that rumen macronutrient balance was tightly related to ingested levels of dietary fiber (cellulose and hemicellulose), such that the greater the fiber content, the less protein was present in the rumen compared with nonstructural carbohydrates. Our results also suggest that moose benefit from access to a greater variety of trees, shrubs, herbs, and grasses, which provides them with a larger nutritional space to maneuver within. Our findings provide novel theoretical insights into a model species for ungulate nutritional ecology, while also generating data of direct relevance to wildlife and forest management, such as silvicultural or supplementary feeding practices.

Balancing macronutrient intake in cultured Lytechinus variegatus

Publisher: Elsevier BV

Date: 2016

DOI: 10.1016/J.AQUACULTURE.2015.08.001

Diet quality in an ethnically diverse population of older men in Australia

Publisher: Springer Science and Business Media LLC

Date: 12-03-2021

DOI: 10.1038/S41430-021-00893-7

Abstract: To compare the Australian Dietary Guideline Index (DGI-2013) and the Pyramid-based Mediterranean Diet Score (pyrMDS) as measures of diet quality in an ethnically erse group of older men. Seven hundred and ninety-four older men aged ≥75 participated in wave 3 (2012-2013) of the Concord Health and Ageing in Men Project. Dietary intake was assessed using a validated diet history questionnaire. Ethnicity was based on self-reported country of birth and categorised as Australian-born (418 men), Italian or Greek migrants (188), and other migrants (188). Incident cardiovascular outcomes until March 2018 were measured using the composite of major adverse cardiovascular events (MACE), which comprises all-cause mortality, acute myocardial infarction, congestive cardiac failure, coronary revascularisation and/or ischaemic stroke. Ability to predict incident cardiovascular outcomes and all-cause mortality were compared between standardised DGI-2013 pyrMDS scores by comparison of hazard ratios, discrimination (Harrell's C-statistic) and calibration (calibration plots). Italian and Greek migrant men had significantly lower DGI-2013 scores (91.7 vs. 93.9 p = 0.01) but significantly higher pyrMDS scores (8.8 vs. 8.2 p < 0.0001) than Australian-born men. In the whole s le (794 men), the pyrMDS was a better predictor of both MACE (age-adjusted HR = 0.84 95% CI = 0.75-0.94 vs. HR = 0.92 95% CI = 0.82-1.03 for DGI-2013) and all-cause mortality (age-adjusted HR = 0.69 95% CI = 0.60-0.80 vs. HR = 0.86 95% CI = 0.74-0.99). The pyrMDS also demonstrated superior discrimination for predicting all-cause mortality and superior calibration for MACE and all-cause mortality. The DGI-2013 appears to underestimate diet quality in older Italian and Greek migrant men. The pyrMDS appears superior to the DGI-2013 for prediction of incident cardiovascular disease and mortality regardless of ethnic background.

Flesh flies regulate the consumption of 3 macronutrients to maximize lifespan and egg production

Publisher: Oxford University Press (OUP)

Date: 22-09-2015

DOI: 10.1093/BEHECO/ARV151

Cost of a naturally occurring two-amino acid deletion in cytochrome c oxidase subunit 7A in Drosophila simulans

Publisher: University of Chicago Press

Date: 10-2010

DOI: 10.1086/656263

Abstract: This study aimed to determine whether a naturally occurring (DeltaTrp85, DeltaVal86) deletion from a protein subunit of cytochrome c oxidase (complex IV) influenced cytochrome c oxidase activity, mRNA expression levels of electron transport chain genes, and aspects of adult female fitness in the fly Drosophila simulans. We modeled the tertiary structure of D. simulans cox7A containing the deletion by homology to the bovine cox7A structure and predicted that it would decrease the function of complex IV. This prediction led to the hypothesis that flies with the deletion would have lower cytochrome c oxidase activity and higher levels of mRNA expression from cox7A. This result was observed, but unexpectedly, elevated levels of mRNA expression were also observed in genes encoding subunits of complexes I, III, and IV. Together these data suggest that the deletion causes a high bioenergetic cost to the organism. To investigate the predicted cost at a physiological level, we assayed aspects of adult female fitness. Starvation sensitivity but not feeding rate was significantly influenced by the two-amino acid deletion. Further, we observed that carbohydrate and protein levels but not lipid levels were higher in the mutant flies. Together, these data show that quaternary structure modeling and biochemistry can be used to link the genotype with the organismal phenotype.

Sex differences in nutrient intake can reduce the potential for sexual conflict over fitness maximization by female and male crickets

Publisher: Wiley

Date: 20-08-2019

DOI: 10.1111/JEB.13513

Abstract: As females and males have different roles in reproduction, they are expected to require different nutrients for the expression of reproductive traits. However, due to their shared genome, both sexes may be constrained in the regulation of nutrient intake that maximizes sex-specific fitness. Here, we used the Geometric Framework for nutrition to examine the effect of macronutrient and micronutrient intakes on lifespan, fecundity and cuticular hydrocarbons (CHCs) that signal mate quality to prospective mates in female field crickets, Teleogryllus oceanicus. In addition, we contrasted nutritional effects on life-history traits between males and females to determine how sex differences influence nutrient regulation. We found that carbohydrate intake maximized female lifespan and protein intake influenced CHC expression, while early life fecundity (cumulative fecundity at day 21) and lifetime fecundity were dependent on both macronutrient and micronutrient intakes. Fecundity required different nutrient blends to those required to optimize sperm viability in males, generating the potential for sexual conflict over macronutrient intake. The regulation of protein (P) and carbohydrate (C) intakes by virgin and mated females initially matched that of males, but females adjusted their intake to a higher P:C ratio, 1P:2C, that maximized fecundity as they aged. This suggests that a sex-specific, age-dependent change in intake target for sexually mature females, regardless of their mating status, adjusts protein consumption in preparation for oviposition. Sex differences in the regulation of nutrient intake to optimize critical reproductive traits in female and male T. oceanicus provide an ex le of how sexual conflict over nutrition can shape differences in foraging between the sexes.

Impact of dietary carbohydrate type and protein–carbohydrate interaction on metabolic health

Publisher: Springer Science and Business Media LLC

Date: 08-06-2021

DOI: 10.1038/S42255-021-00393-9

Abstract: Reduced protein intake, through dilution with carbohydrate, extends lifespan and improves mid-life metabolic health in animal models. However, with transition to industrialised food systems, reduced dietary protein is associated with poor health outcomes in humans. Here we systematically interrogate the impact of carbohydrate quality in diets with varying carbohydrate and protein content. Studying 700 male mice on 33 isocaloric diets, we find that the type of carbohydrate and its digestibility profoundly shape the behavioural and physiological responses to protein dilution, modulate nutrient processing in the liver and alter the gut microbiota. Low (10%)-protein, high (70%)-carbohydrate diets promote the healthiest metabolic outcomes when carbohydrate comprises resistant starch (RS), yet the worst outcomes were with a 50:50 mixture of monosaccharides fructose and glucose. Our findings could explain the disparity between healthy, high-carbohydrate diets and the obesogenic impact of protein dilution by glucose-fructose mixtures associated with highly processed diets.

Splicing across adipocyte differentiation is highly dynamic and impacted by metabolic phenotype

Publisher: Research Square Platform LLC

Date: 31-10-2023

DOI: 10.21203/RS.3.RS-3487148/V1

Consistent proportional macronutrient intake selected by adult domestic cats (Felis catus) despite variations in macronutrient and moisture content of foods offered

Publisher: Springer Science and Business Media LLC

Date: 12-12-2013

DOI: 10.1007/S00360-012-0727-Y

TNIK is a conserved regulator of glucose and lipid metabolism in obesity

Publisher: American Association for the Advancement of Science (AAAS)

Date: 09-08-2023

DOI: 10.1126/SCIADV.ADF7119

Abstract: Obesity and type 2 diabetes (T2D) are growing health challenges with unmet treatment needs. Traf2- and NCK-interacting protein kinase (TNIK) is a recently identified obesity- and T2D-associated gene with unknown functions. We show that TNIK governs lipid and glucose homeostasis in Drosophila and mice. Loss of the Drosophila ortholog of TNIK , misshapen , altered the metabolite profiles and impaired de novo lipogenesis in high sugar–fed larvae. Tnik knockout mice exhibited hyperlocomotor activity and were protected against diet-induced fat expansion, insulin resistance, and hepatic steatosis. The improved lipid profile of Tnik knockout mice was accompanied by enhanced skeletal muscle and adipose tissue insulin-stimulated glucose uptake and glucose and lipid handling. Using the T2D Knowledge Portal and the UK Biobank, we observed associations of TNIK variants with blood glucose, HbA1c, body mass index, body fat percentage, and feeding behavior. These results define an untapped paradigm of TNIK-controlled glucose and lipid metabolism.

Phase polyphenism and preventative locust management

Publisher: Elsevier BV

Date: 08-2010

DOI: 10.1016/J.JINSPHYS.2010.05.005

Abstract: The ecology of phase polyphenism plays a major role in locust swarm formation. We describe how recent advances in the understanding of phase polyphenism can be combined with existing management approaches as part of a preventative Desert locust management strategy. We start with a brief overview of phase polyphenism with particular emphasis on the role that resource distribution patterns play in the process of locust phase change. We then review current perspective on preventative locust management, and conclude by proposing a framework for quantitatively assessing the risk that phase change will occur in local locust populations. Importantly, the data required to implement this framework can be readily collected with little additional effort or cost just by slightly modifying locust habitat survey protocols that are already in operation. Incorporating gregarization risk assessment into existing preventative management strategies stands to make a considerable contribution toward realizing sustainable goals of reductions in the pesticide, manpower and financial support necessary to combat Desert locust upsurges, outbreaks and ultimately plagues.

Nutrient-specific foraging in invertebrate predators

Publisher: American Association for the Advancement of Science (AAAS)

Date: 07-01-2005

DOI: 10.1126/SCIENCE.1105493

Abstract: Many herbivores and omnivores adjust their food selection behavior to regulate the intake of multiple nutrients. Carnivores, however, are generally assumed to optimize the rate of prey capture rather than select prey according to nutrient composition. We showed experimentally that invertebrate predators can forage selectively for protein and lipids to redress specific nutritional imbalances. This selection can take place at different stages of prey handling: The predator may select among foods of different nutritional composition, eat more of a prey if it is rich in nutrients that the predator is deficient in, or extract specific nutrients from a single prey item.

The association between the macronutrient content of maternal diet and the adequacy of micronutrients during pregnancy in the Women and Their Children’s Health (WATCH) study.

Publisher: MDPI AG

Date: 06-12-2012

DOI: 10.3390/NU4121958

Communal Nutrition in Ants

Publisher: Elsevier BV

Date: 05-2009

DOI: 10.1016/J.CUB.2009.03.015

Abstract: Studies on nonsocial insects have elucidated the regulatory strategies employed to meet nutritional demands [1-3]. However, how social insects maintain the supply of an appropriate balance of nutrients at both a collective and an in idual level remains unknown. Sociality complicates nutritional regulatory strategies [4-6]. First, the food entering a colony is collected by a small number of workers, which need to adjust their harvesting strategy to the demands for nutrients among in iduals within the colony [4-7]. Second, because carbohydrates are used by the workers and proteins consumed by the larvae [7-14], nutritional feedbacks emanating from both must exist and be integrated to determine food exploitation by foragers [4-6, 15, 16]. Here, we show that foraging ants can solve nutritional challenges for the colony by making intricate adjustments to their feeding behavior and nutrient processing, acting both as a collective mouth and gut. The amount and balance of nutrients collected and the precision of regulation depend on the presence of larvae in the colony. Ants improved the macronutrient balance of collected foods by extracting carbohydrates and ejecting proteins. Nevertheless, processing excess protein shortened life span--an effect that was greatly ameliorated in the presence of larvae.

Putting the balance back in diet

Publisher: Elsevier BV

Date: 03-2015

DOI: 10.1016/J.CELL.2015.02.033

Abstract: The notion of dietary balance is fundamental to health yet is not captured by focusing on the intake of energy or single nutrients. Advances in nutritional geometry have begun to unravel and integrate the interactive effects of multiple nutrients on health, lifespan, aging, and reproduction.

FGF21 Signals Protein Status to the Brain and Adaptively Regulates Food Choice and Metabolism

Publisher: Elsevier BV

Date: 06-2019

DOI: 10.1016/J.CELREP.2019.05.022

Behavioral Microbiomics: A Multi-Dimensional Approach to Microbial Influence on Behavior

Publisher: Frontiers Media SA

Date: 27-11-2015

DOI: 10.3389/FMICB.2015.01359

Branched Chain Amino Acids, Cardiometabolic Risk Factors and Outcomes in Older Men: The Concord Health and Ageing in Men Project

Publisher: Oxford University Press (OUP)

Date: 20-08-2019

DOI: 10.1093/GERONA/GLZ192

Abstract: Increased blood levels of branched chain amino acids (BCAAs) have been associated with cardiometabolic risk factors. Here, we studied 918 community-dwelling older men to determine the relationship between BCAAs and other amino acids with cardiometabolic risk factors, major cardiovascular endpoints (MACE), and mortality. BCAAs had robust associations with many adverse metabolic risk factors (increased glucose, insulin, Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), triglycerides decreased high-density lipoprotein cholesterol). However, paradoxically, participants with lower levels of BCAAs had greater mortality and MACE possibly because increasing age and frailty, both of which were associated with lower BCAA levels, are powerful risk factors for these outcomes in older people. Overall, amino acids that were lowest in frail subjects (BCAAs, α-aminobutyric acid [AABA], histidine, lysine, methionine, threonine, tyrosine) were inversely associated with mortality and MACE. In conclusion, BCAAs are biomarkers for important outcomes in older people including cardiometabolic risk factors, frailty, and mortality. In old age, frailty becomes a dominant risk factor for MACE and mortality.

Mechanoresponsive neurones in the suboesophageal ganglion of the locust

Publisher: Wiley

Date: 12-1992

DOI: 10.1111/J.1365-3032.1992.TB01033.X

The nutritional balancing act of a large herbivore: An Experiment with Captive Moose (Alces alces L)

Publisher: Public Library of Science (PLoS)

Date: 17-03-2016

DOI: 10.1371/JOURNAL.PONE.0150870

Protein and Calorie Restriction Contribute Additively to Protection from Renal Ischemia Reperfusion Injury Partly via Leptin Reduction in Male Mice

Publisher: Elsevier BV

Date: 08-2015

DOI: 10.3945/JN.114.199380

Associations between dietary intake of total protein and sources of protein (plant vs. animal) and risk of all‐cause and cause‐specific mortality in older Australian men: The Concord Health and Ageing

Publisher: Wiley

Date: 21-11-2021

DOI: 10.1111/JHN.12965

Abstract: The association between dietary protein intake and the risk of mortality is still controversial. The present study aimed to examine the associations between dietary total, animal and plant protein intake and all‐cause and cause‐specific mortality. Community‐dwelling men aged ≥ 70 years were recruited from local government areas surrounding Concord Hospital in Sydney, New South Wales for the Concord Health and Ageing in Men Project (CHAMP). The research dietitian administered a standardised validated diet history questionnaire to capture baseline dietary intake. In total, 794 men participated in a detailed diet history interview at the third wave. Adequacy of protein intake was assessed by comparing participant intake with the Nutrient Reference Values. Total protein intake was categorised into quintiles. Sources of protein were also captured. Mortality was ascertained through the New South Wales death registry. Cox proportional hazard models were used to assess the association between dietary total, animal and plant protein intake and risk of mortality. The mean age of the CHAMP men was 81 years. In total, 162 men died during a median follow‐up of 3.7 years. Of these, 54 (33.3%) and 49 (30.2%) men died due to cancer and cardiovascular disease, respectively. There were U‐shaped associations between protein intake and all‐cause and cancer mortality. In multiple adjusted analysis, the second (hazard ratio [HR] = 0.38 95% confidence interval [CI] = 0.18–0.82) and third (HR = 0.36 95% CI = 0.16–0.82) quintiles of protein intakes were significantly associated with reduced risk of all‐cause and only second quintile (HR = 0.47 95% CI = 0.10–0.93) of protein intake was significantly associated with cancer mortality. Each serve increase in animal protein was significantly associated with 12% (HR = 1.12 95% CI = 1.00–1.26) and 23% (HR = 1.23 95% CI = 1.02–1.49) increased risk of all‐cause mortality and cancer mortality respectively. Conversely, each serve increase in plant protein intake was significantly associated with 25% (HR = 0.75 95% CI 0.61–0.92) and 28% (HR = 0.72 95% CI = 0.53–0.97) reduced risk of all‐cause and cancer mortality, respectively. No such associations were observed for cardiovascular disease mortality. Both second and third quintiles of total protein intake were associated with reduced all‐cause and cancer mortality. Plant protein was inversely associated with all‐cause and cancer mortality, whereas animal protein intake was positively associated with mortality.

Nutritional reprogramming of mouse liver proteome is dampened by metformin, resveratrol, and rapamycin

Publisher: Elsevier BV

Date: 12-2021

DOI: 10.1016/J.CMET.2021.10.016

Abstract: Nutrient sensing pathways influence metabolic health and aging, offering the possibility that diet might be used therapeutically, alone or with drugs targeting these pathways. We used the Geometric Framework for Nutrition to study interactive and comparative effects of diet and drugs on the hepatic proteome in mice across 40 dietary treatments differing in macronutrient ratios, energy density, and drug treatment (metformin, rapamycin, resveratrol). There was a strong negative correlation between dietary energy and the spliceosome and a strong positive correlation between dietary protein and mitochondria, generating oxidative stress at high protein intake. Metformin, rapamycin, and resveratrol had lesser effects than and d ened responses to diet. Rapamycin and metformin reduced mitochondrial responses to dietary protein while the effects of carbohydrates and fat were downregulated by resveratrol. Dietary composition has a powerful impact on the hepatic proteome, not just on metabolic pathways but fundamental processes such as mitochondrial function and RNA splicing.

Macronutrients and micronutrients drive trade‐offs between male pre‐ and postmating sexual traits

Publisher: Wiley

Date: 16-08-2018

DOI: 10.1111/1365-2435.13190

The impact of low-protein high-carbohydrate diets on aging and lifespan

Publisher: Springer Science and Business Media LLC

Date: 30-12-2016

DOI: 10.1007/S00018-015-2120-Y

The influence of macronutrients on splanchnic and hepatic lymphocytes in aging mice

Publisher: Oxford University Press (OUP)

Date: 21-10-2015

DOI: 10.1093/GERONA/GLU196

Abstract: There is a strong association between aging, diet, and immunity. The effects of macronutrients and energy intake on splanchnic and hepatic lymphocytes were studied in 15 month old mice. The mice were ad-libitum fed 1 of 25 diets varying in the ratios and amounts of protein, carbohydrate, and fat over their lifetime. Lymphocytes in liver, spleen, Peyers patches, mesenteric lymph nodes, and inguinal lymph nodes were evaluated using flow cytometry. Low protein intake reversed aging changes in splenic CD4 and CD8 T cells, CD4:CD8 T cell ratio, memory/effector CD4 T cells and naïve CD4 T cells. A similar influence of total caloric intake in these ad-libitum fed mice was not apparent. Protein intake also influenced hepatic NK cells and B cells, while protein to carbohydrate ratio influenced hepatic NKT cells. Hepatosteatosis was associated with increased energy and fat intake and changes in hepatic Tregs, effector/memory T, and NK cells. Hepatic NK cells were also associated with body fat, glucose tolerance, and leptin levels while hepatic Tregs were associated with hydrogen peroxide production by hepatic mitochondria. Dietary macronutrients, particularly protein, influence splanchnic lymphocytes in old age, with downstream associations with mitochondrial function, liver pathology, and obesity-related phenotype.

Dietary and supplemental antioxidant intake and risk of major adverse cardiovascular events in older men: The concord health and ageing in men project

Publisher: Elsevier BV

Date: 04-2021

DOI: 10.1016/J.NUMECD.2020.11.032

Nutrient regulation in relation to diet breadth: a comparison ofHeliothissister species and a hybrid

Publisher: The Company of Biologists

Date: 06-2006

DOI: 10.1242/JEB.02253

Abstract: We examined the nutritional correlates of diet breadth in insect herbivores by comparing patterns of diet selection, nutrient balancing, post-ingestive utilization and development in two sister species of caterpillar and a hybrid between them. One species, Heliothis virescens (HV) has a broad host range, feeding on plants in at least 14 families. The other, Heliothis subflexa (HS), is a specialist on plants in the genus Physalis(Solanaceae). Experiments using synthetic foods showed that when the caterpillars were allowed to mix their diet, the generalist self-selected a higher-protein diet whereas the specialist ate almost equal amounts of protein and carbohydrate, which accords with differences between the two species in the nutrient content of their natural diets. When confined to nutritionally imbalanced diets, the generalist showed a propensity to over-eat high protein:carbohydrate (P:C) diets to a greater degree than did the specialist and maintained higher rates of development. The generalist did not, however,over-eat low P:C diets to the same degree as the specialist. The hybrid selected a diet composition that was indistinguishable to that of its generalist father (HV), while its response to imbalanced diets was closely similar to that of the specialist mother (HS). The generalist converted ingested nutrient to growth with lower efficiency than did the specialist and the hybrid. Our findings imply that different behavioural and physiological traits linked to nutrient regulation are under genetic control and are explicable in terms of the different life-histories, feeding ecologies and presumed levels of nutritional heterogeneity in the environments of the two insects.

Mechanosensory-induced behavioural gregarization in the desert locustSchistocerca gregaria

Publisher: The Company of Biologists

Date: 15-11-2003

DOI: 10.1242/JEB.00648

Abstract: Desert locusts show an extreme form of phenotypic plasticity, changing between a cryptic solitarious phase and a swarming gregarious phase that differ in many aspects of behaviour, physiology and appearance. Solitarious locusts show rapid behavioural phase change in response to tactile stimulation directed to the hind femora. Repeatedly touching as little as one quarter of the anterior (outer) surface area of a hind femur produced full behavioural gregarization within 4 h. Solitarious locusts have approximately 30% more mechanosensory trichoid sensilla on the hind femora than do gregarious locusts but have similar or fewer numbers of sensilla elsewhere on the legs. Tactile stimulation of a hind femur in solitarious locusts that had been restrained so that they could not move their legs failed to induce any behavioural gregarization. Patterned electrical stimulation of metathoracic nerve 5, which innervates the hind leg, however, produced full gregarization in restrained locusts. Our data show for the first time that the gregarizing signal combines both exteroceptive and proprioceptive components, which travel in both nerves 5B1 and 5B2, and provides us with a powerful experimental method with which to elicit and study neuronal plasticity in this system. Acetic acid odour, a strong chemosensory stimulus that activates the same local processing pathways as exteroceptive stimuli, failed to elicit behavioural gregarization,suggesting an early segregation in the central nervous system of the mechanosensory signals that leads to gregarization.

Midnight snacks might shorten your life: lifespan and healthspan advantages of eating less and at the right time

Publisher: Oxford University Press (OUP)

Date: 2023

DOI: 10.1093/CVR/CVAD018

Testing protein leverage in lean humans: a randomised controlled experimental study

Publisher: Public Library of Science (PLoS)

Date: 12-10-2011

DOI: 10.1371/JOURNAL.PONE.0025929

Nutritional Immunology: A Multi-Dimensional Approach

Publisher: Public Library of Science (PLoS)

Date: 12-2011

DOI: 10.1371/JOURNAL.PPAT.1002223

Gross vs. net income: How plant toughness affects performance of an insect herbivore

Publisher: Wiley

Date: 12-2009

DOI: 10.1890/09-0130.1

Abstract: Leaf biomechanical properties are thought to impose a significant obstacle to herbivores and as such influence patterns of herbivory more than leaf chemistry. However, evidence for the role of structural traits in influencing herbivore food choice and performance has come from correlative studies, whereas the underlying mechanisms have been given little attention. By manipulating the biomechanical properties of a host grass species through a combination of lyophilization and milling, and providing water separately, we were able to compare behavioral, physiological, and developmental responses of the Australian plague locust, Chortoicetes terminifera, to the biomechanical properties of plant food (exemplified by toughness) independently of the food's macronutrient content and the insect's demand for water. Increasing leaf toughness was associated with reduced rates of locust growth and prolonged development, with potential ecological consequences. Poorer performance on the tougher foods was primarily a consequence of a reduced rate of nutrient supply, which occurred as a result of (1) smaller meals being eaten more slowly, (2) slowed gut passage rates, which limited how quickly the next meal could be taken, and (3) reduced efficiency of assimilation of nutrients from food in the gut. In addition, there were deleterious changes in the ratio of protein to carbohydrate assimilated from the gut. Prolonged development time was associated with increased total nutrient demands throughout the extended developmental period. Because these demands could not be met by increased consumption, there was a decreased efficiency of conversion of assimilated nutrients to growth. By disentangling the effects of biomechanical properties from macronutrient and water content we have shown that leaf biomechanical traits can influence chewing herbivores independently of leaf chemical traits.

A vertebrate, the fence skink, is a common but relatively low-quality prey for an invertebrate predator, the redback spider

Publisher: Elsevier BV

Date: 09-2022

DOI: 10.1016/J.FOOWEB.2022.E00236

Geometric analysis of macronutrient selection in the adult domestic cat, felis catus

Publisher: The Company of Biologists

Date: 15-03-2011

DOI: 10.1242/JEB.049429

Abstract: We report feeding studies on adult domestic cats designed to disentangle the complex interactions among dietary protein, fat and carbohydrate in the control of intake. Using geometric techniques that combine mixture triangles and intake plots from the geometric framework, we: (1) demonstrate that cats balance their macronutrient intake, (2) estimate the composition of the target balance and (3) reveal the priorities given to different macronutrients under dietary conditions where the target is unachievable. Our analysis indicates that cats have a ceiling for carbohydrate intake, which limits ingestion and constrains them to deficits in protein and fat intake (relative to their target) on high-carbohydrate foods. Finally, we reanalyse data from a previous experiment that claimed that kittens failed to regulate protein intake, and show that, in fact, they did. These results not only add to the growing appreciation that carnivores, like herbivores and omnivores, regulate macronutrient intake, they also have important implications for designing feeding regimens for companion animals.

Integrating nutrition and immunology: A new frontier

Publisher: Elsevier BV

Date: 02-2013

DOI: 10.1016/J.JINSPHYS.2012.10.011

Abstract: Nutrition is critical to immune defence and parasite resistance, which not only affects in idual organisms, but also has profound ecological and evolutionary consequences. Nutrition and immunity are complex traits that interact via multiple direct and indirect pathways, including the direct effects of nutrition on host immunity but also indirect effects mediated by the host's microbiota and pathogen populations. The challenge remains, however, to capture the complexity of the network of interactions that defines nutritional immunology. The aim of this paper is to discuss the recent findings in nutritional research in the context of immunological studies. By taking ex les from the entomological literature, we argue that insects provide a powerful tool for examining the network of interactions between nutrition and immunity due to their tractability, short lifespan and ethical considerations. We describe the relationships between dietary composition, immunity, disease and microbiota in insects, and highlight the importance of adopting an integrative and multi-dimensional approach to nutritional immunology.

Group structure in locust migratory bands

Publisher: Springer Science and Business Media LLC

Date: 19-08-2011

DOI: 10.1007/S00265-010-1041-X

Nutritional ecology of obesity: from humans to companion animals

Publisher: Cambridge University Press (CUP)

Date: 21-11-2014

DOI: 10.1017/S0007114514002323

Abstract: We apply nutritional geometry, a framework for modelling the interactive effects of nutrients on animals, to help understand the role of modern environments in the obesity pandemic. Evidence suggests that humans regulate the intake of protein energy (PE) more strongly than non-protein energy (nPE), and consequently will over- and under-ingest nPE on diets with low or high PE, respectively. This pattern of macronutrient regulation has led to the protein leverage hypothesis, which proposes that the rise in obesity has been caused partly by a shift towards diets with reduced PE:nPE ratios relative to the set point for protein regulation. We discuss potential causes of this mismatch, including environmentally induced reductions in the protein density of the human diet and factors that might increase the regulatory set point for protein and hence exacerbate protein leverage. Economics – the high price of protein compared with fats and carbohydrates – is one factor that might contribute to the reduction of dietary protein concentrations. The possibility that rising atmospheric CO 2 levels could also play a role through reducing the PE:nPE ratios in plants and animals in the human food chain is discussed. Factors that reduce protein efficiency, for ex le by increasing the use of ingested amino acids in energy metabolism (hepatic gluconeogenesis), are highlighted as potential drivers of increased set points for protein regulation. We recommend that a similar approach is taken to understand the rise of obesity in other species, and identify some key gaps in the understanding of nutrient regulation in companion animals.

Speed over efficiency: locusts select body temperatures that favour growth rate over efficient nutrient utilization

Publisher: The Royal Society

Date: 22-07-2009

DOI: 10.1098/RSPB.2009.1030

Abstract: Ectotherms have evolved preferences for particular body temperatures, but the nutritional and life-history consequences of such temperature preferences are not well understood. We measured thermal preferences in Locusta migratoria (migratory locusts) and used a multi-factorial experimental design to investigate relationships between growth/development and macronutrient utilization (conversion of ingesta to body mass) as a function of temperature. A range of macronutrient intake values for insects at 26, 32 and 38°C was achieved by offering in iduals high-protein diets, high-carbohydrate diets or a choice between both. Locusts placed in a thermal gradient selected temperatures near 38°C, maximizing rates of weight gain however, this enhanced growth rate came at the cost of poor protein and carbohydrate utilization. Protein and carbohydrate were equally digested across temperature treatments, but once digested both macronutrients were converted to growth most efficiently at the intermediate temperature (32°C). Body temperature preference thus yielded maximal growth rates at the expense of efficient nutrient utilization.

Nutrition, ecology and nutritional ecology: Toward an integrated framework

Publisher: Wiley

Date: 16-01-2009

DOI: 10.1111/J.1365-2435.2009.01522.X

Projected effects on salt purchases following implementation of a national salt reduction policy in South Africa

Publisher: Cambridge University Press (CUP)

Date: 28-12-2021

DOI: 10.1017/S1368980020005273

Abstract: To assess the contribution of different food groups to total salt purchases and to evaluate the estimated reduction in salt purchases if mandatory maximum salt limits in South African legislation were being complied with. This study conducted a cross-sectional analysis of purchasing data from Discovery Vitality members. Data were linked to the South African FoodSwitch database to determine the salt content of each food product purchased. Food category and total annual salt purchases were determined by summing salt content (kg) per each unit purchased across a whole year. Reductions in annual salt purchases were estimated by applying legislated maximum limits to product salt content. South Africa. The study utilised purchasing data from 344 161 households, members of Discovery Vitality, collected for a whole year between January and December 2018. Vitality members purchased R12·8 billion worth of food products in 2018, representing 9562 products from which 264 583 kg of salt was purchased. The main contributors to salt purchases were bread and bakery products (23·3 %) meat and meat products (19 %) dairy (12·2 %) sauces, dressings, spreads and dips (11·8 %) and convenience foods (8·7 %). The projected total quantity of salt that would be purchased after implementation of the salt legislation was 250 346 kg, a reduction of 5·4 % from 2018 levels. A projected reduction in salt purchases of 5·4 % from 2018 levels suggests that meeting the mandatory maximum salt limits in South Africa will make a meaningful contribution to reducing salt purchases.

Prospective Associations Between Dietary Antioxidant Intake and Frailty in Older Australian Men: The Concord Health and Ageing in Men Project

Publisher: Oxford University Press (OUP)

Date: 06-04-2019

DOI: 10.1093/GERONA/GLZ054

Abstract: The objective of the study is to evaluate the prospective associations between antioxidant intake and incident frailty among older Australian men aged ≥75 years. Seven hundred and ninety-four men participated in a detailed diet history interview at the Concord Health and Ageing in Men Project (CHAMP) study third wave (considered baseline nutrition here) and 781 men participated at the fourth wave (considered 3-year follow-up here). The main outcome measurement was incident frailty at 3-year follow-up, using the Cardiovascular Health Study definition. Dietary adequacy of antioxidant intake was assessed by comparing participants' median intakes of four dietary antioxidants (vitamin A, E, C, and zinc) to the nutrient reference values (NRVs). Attainment of the NRVs was incorporated into a dichotomized variable "poor" (meeting ≤2 antioxidants) or "good" (meeting ≥3 antioxidants) as the independent variable using the cut-point method. Also, intakes of each in idual dietary antioxidant at baseline nutrition were categorized into quartiles. Analyses were performed using multinomial logistic regression. Incidence of pre-frailty was 53.0% and frailty was 6.4% at 3-year follow-up. Poor dietary antioxidant intake (meeting ≤2) at baseline nutrition was associated with incident frailty at 3-year follow-up in unadjusted (OR: 2.59 [95% CI: 1.47, 4.59, p = .001]) and adjusted (OR: 2.46 [95% CI: 1.10, 5.51, p = .03]) analyses. The lowest quartile of vitamin E intake (<7.08 mg/d) was significantly associated with incident frailty (OR: 2.46 [95% CI: 1.01, 6.00, p = .05]). Poor antioxidant intake, particularly vitamin E, is a plausible factor associated with incident frailty among older men. This supports the need for clinical trials of diets rich in antioxidants or possibly low-dose antioxidant supplements, for prevention of frailty.

Macronutrient balance, reproductive function, and lifespan in aging mice

Publisher: Proceedings of the National Academy of Sciences

Date: 02-03-2015

DOI: 10.1073/PNAS.1422041112

Abstract: A fundamental tenet of life-history theory is that reproduction and longevity trade off against one another. Experiments on invertebrates show that, rather than competing for limiting resources, reproduction and lifespan are optimized on different dietary macronutrient compositions. In mice, studies have yet to establish the relationship between macronutrient balance, reproduction, and lifespan. We evaluated the effects of macronutrients and energy on lifespan and reproductive function. Indicators of reproductive function (uterine mass, ovarian follicle number, testes mass, epididymal sperm counts) were optimized by high protein (P), low carbohydrate (C) diets whereas lifespan was greatest on low P:C diets. Corpora lutea and estrous cycling were higher in females on lower P:C diets. Macronutrient balance has profound and opposing effects on reproduction and longevity.

Evolving Nutritional Strategies in the Presence of Competition: A Geometric Agent-Based Model

Publisher: Public Library of Science (PLoS)

Date: 27-03-2015

DOI: 10.1371/JOURNAL.PCBI.1004111

Modeling spatiotemporal dynamics of outbreaking species: influence of environment and migration in a locust

Publisher: Wiley

Date: 03-2015

DOI: 10.1890/14-0183.1

Abstract: Many pest species exhibit huge fluctuations in population abundance. Understanding their large-scale and long-term dynamics is necessary to develop effective control and management strategies. Occupancy models represent a promising approach to unravel interactions between environmental factors and spatiotemporal dynamics of outbreaking populations. Here, we investigated population dynamics of the Australian plague locust, Chortoicetes terminifera, using density data collected between 1988 and 2010 by the Australian Plague Locust Commission over more than 3 million km2 in eastern Australia. We applied multistate and autologistic multi-season occupancy models to test competing hypotheses about environmental and demographic processes affecting the large-scale dynamics of the Australian plague locust. We found that rainfall and land cover predictors best explained the spatial variability in outbreak probability across eastern Australia. Outbreaks are more likely to occur in temperate than tropical regions, with a faster and more continuous response to rainfall in desert than in agricultural areas. Our results also support the hypothesis that migration tends to propagate outbreaks only locally (over distances lower than 400 km) rather than across climatic regions. Our study suggests that locust outbreak forecasting and management systems could be improved by implementing key environmental factors and migration in hierarchical spatial models. Finally, our modeling framework can be seen as a step towards bridging the gap between mechanistic and more phenomenological models in the spatial analysis of fluctuating populations.

Dietary macronutrient content, age-specific mortality and lifespan

Publisher: The Royal Society

Date: 05-2019

DOI: 10.1098/RSPB.2019.0393

Abstract: Protein and calorie restrictions extend median lifespan in many organisms. However, studies suggest that among-in idual variation in the age at death is also affected. Ultimately, both of these outcomes must be caused by effects of nutrition on underlying patterns of age-specific mortality (ASM). Using model life tables , we tested for effects of dietary macronutrients on ASM in mice ( Mus musculus ). High concentrations of protein and fat relative to carbohydrates were associated with low life expectancy and high variation in the age at death, a result caused predominantly by high mortality prior to middle age. A lifelong diet comprising the ratio of macronutrients self-selected by mouse (in early adulthood) was associated with low mortality up until middle age, but higher late-life mortality. This pattern results in reasonably high life expectancy, but very low variation in the age at death. Our analyses also indicate that it may be possible to minimize ASM across life by altering the ratio of dietary protein to carbohydrate in the approach to old age. Mortality in early and middle life was minimized at around one-part protein to two-parts carbohydrate, whereas in later life slightly greater than equal parts protein to carbohydrate reduced mortality.

Animal and translational models of SARS-CoV-2 infection and COVID-19

Publisher: Elsevier BV

Date: 11-2020

DOI: 10.1038/S41385-020-00340-Z

Weight gain during the menopause transition: Evidence for a mechanism dependent on protein leverage

Publisher: Wiley

Date: 25-09-2023

DOI: 10.1111/1471-0528.17290

Cannibalism can drive the evolution of behavioural phase polyphenism in locusts

Publisher: Wiley

Date: 08-08-2012

DOI: 10.1111/J.1461-0248.2012.01840.X

Abstract: During outbreaks, locust swarms can contain millions of insects travelling thousands of kilometers while devastating vegetation and crops. Such large-scale spatial organization is preceded locally by a dramatic density-dependent phenotypic transition in multiple traits. Behaviourally, low-density 'solitarious' in iduals avoid contact with one another above a critical local density, they undergo a rapid behavioural transition to the 'gregarious phase' whereby they exhibit mutual attraction. Although proximate causes of this phase polyphenism have been widely studied, the ultimate driving factors remain unclear. Using an in idual-based evolutionary model, we reveal that cannibalism, a striking feature of locust ecology, could lead to the evolution of density-dependent behavioural phase-change in juvenile locusts. We show that this behavioural strategy minimizes risk associated with cannibalistic interactions and may account for the empirically observed persistence of locust groups during outbreaks. Our results provide a parsimonious explanation for the evolution of behavioural plasticity in locusts.

Of older mice and men: Branched-chain amino acids and body composition

Publisher: MDPI AG

Date: 13-08-2019

DOI: 10.3390/NU11081882

Abstract: Protein and branched-chain amino acid (BCAA) intake are associated with changes in circulating BCAAs and influence metabolic health in humans and rodents. However, the relationship between BCAAs and body composition in both species is unclear, with many studies questioning the translatability of preclinical findings to humans. Here, we assessed and directly compared the relationship between circulating BCAAs, body composition, and intake in older mice and men. Body weight and body fat were positively associated with circulating BCAA levels in both mouse and human, which remained significant after adjustments for age, physical activity, number of morbidities, smoking status, and source of income in the human cohort. Macronutrient intakes were similarly associated with circulating BCAA levels however, the relationship between protein intake and BCAAs were more pronounced in the mice. These findings indicate that the relationship between circulating BCAAs, body composition, and intakes are comparable in both species, suggesting that the mouse is an effective model for examining the effects of BCAAs on body composition in older humans.

A comparison of nutrient regulation between solitarious and gregarious phases of the specialist caterpillar, Spodoptera exempta (Walker)

Publisher: Elsevier BV

Date: 12-2004

DOI: 10.1016/J.JINSPHYS.2004.10.009

Abstract: Nutritional regulatory responses were compared between solitarious and gregarious phases of the African armyworm, Spodoptera exempta. When allowed to mix between two nutritionally imbalanced but complementary foods, final-instar caterpillars in both phases selected a diet comprising more carbohydrate than protein. This contrasts with other larval lepidopterans studied to date. Only minor differences were found in the position of the intake target for the two phases, despite their different energetic requirements for migration as adults. When restricted to nutritionally imbalanced diets, caterpillars of both phases were less disposed to overeat protein on high-protein diets than carbohydrate on high-carbohydrate diets, relative to the self-composed intake target. However, in both cases gregarious larvae overingested the excess nutrient to a greater degree than did solitarious larvae. Furthermore, gregarious larvae showed higher nitrogen conversion efficiency on an extreme protein-limiting diet, and accumulated more lipid per amount of carbohydrate consumed on carbohydrate-deficient diets. These phase-associated nutritional differences are consistent with the life-history strategies of the two phases.

How do travelers manage jetlag and travel fatigue? A survey of passengers on long-haul flights

Publisher: Informa UK Limited

Date: 21-09-2020

DOI: 10.1080/07420528.2020.1787427

Alternative migratory locust phenotypes are associated with differences in the expression of genes encoding the methylation machinery

Publisher: Wiley

Date: 27-11-2016

DOI: 10.1111/IMB.12203

Abstract: Despite the importance of locust density-dependent polyphenism as a model system for understanding phenotypic plasticity, there is still much to be learnt about its underlying molecular control. Here we describe the first investigation into the expression of genes encoding the DNA methylation machinery in the migratory locust (Locusta migratoria). We show that the alternative solitarious and gregarious phenotypic states induced by different locust rearing densities are associated with significant differences in the expression of the target genes DNA methyltransferase 1, DNA methyltransferase 2 and methyl-CpG-binding domain protein 2/3. This variation was most pronounced in the embryos of solitarious vs. gregarious mothers. We mapped the embryonic methylation profiles of several intragenic regions and a Long Interspersed Nuclear Element (LINE), each of which is known to be differentially expressed between alternative locust phenotypes or has been directly implicated in phase change. LmI and three genes, adenyl cyclase-associated binding protein 2, choline kinase alpha-like and henna, were methylated. Our results set the stage for future studies investigating the specific role of DNA methylation in the maternal transfer of migratory locust phase polyphenism.

The Social Context of Cannibalism in Migratory Bands of the Mormon Cricket

Publisher: Public Library of Science (PLoS)

Date: 14-12-2010

DOI: 10.1371/JOURNAL.PONE.0015118

An overlooked consequence of dietary mixing: A varied diet reduces interindividual variance in fitness

Publisher: University of Chicago Press

Date: 11-2015

DOI: 10.1086/683182

Abstract: The determinants of diet breadth are of interest to nutritionists, ecologists, and evolutionary biologists. A recent synthesis addressing this issue found conflicting evidence for the relationship between diet breadth and mean in idual fitness. Specifically, it found that while, on average, a mixed diet does increase mean fitness, in some instances, a single food provides equal (or higher) fitness than a mixed diet. Critical to ecological and evolutionary considerations of diet, however, is not only mean fitness but also variance in fitness. We combine contemporary meta-analytic methods with models of nutritional geometry to evaluate how diet affects between-in idual variance in fitness within generalist consumers from a range of trophic levels. As predicted by nutritional geometry, we found that between-in idual variance in fitness-related traits is higher on single-food than mixed diets. The effect was strong for longevity traits (57% higher) and reproductive traits (37%) and present but weaker for size-related traits (10%). Further, the effect became stronger as the number of available foods increased. The availability of multiple foods likely allows in iduals with differing nutritional optima to customize intake, each maximizing their own fitness. Importantly, these findings may suggest that selection on traits correlated with nutritional requirements is weak in heterogeneous nutritional environments.

Global associations between macronutrient supply and age-specific mortality

Publisher: Proceedings of the National Academy of Sciences

Date: 16-11-2020

DOI: 10.1073/PNAS.2015058117

Abstract: We compiled the most extensive dataset to date of corresponding national macronutrient supplies, survival statistics, and economic data. We show that the national macronutrient supply is a strong predictor of the pattern of mortality in different age classes. Our analyses can show how the optimum macronutrient supply that is predicted to maximize survival changes with age. In early life, equal amounts of fat and carbohydrate are predicted to improve survival. However, as we age, reducing fat in exchange for carbohydrates is associated with the lowest rates of mortality. Our results accord with published experimental and epidemiological data and can help define the mechanisms by which food supply and intake affect public health and demographic processes.

Sex differences in nutrient-dependent reproductive ageing

Publisher: Wiley

Date: 26-05-2009

DOI: 10.1111/J.1474-9726.2009.00479.X

Abstract: Evolutionary theories of aging predict that fitness-related traits, including reproductive performance, will senesce because the strength of selection declines with age. Sexual selection theory predicts, however, that male reproductive performance (especially sexual advertisement) will increase with age. In both bodies of theory, diet should mediate age-dependent changes in reproductive performance. In this study, we show that the sexes exhibit dramatic, qualitative differences in age-dependent reproductive performance trajectories and patterns of reproductive ageing in the cricket Teleogryllus commodus. In females, fecundity peaked early in adulthood and then declined. In contrast, male sexual advertisement increased across the natural lifespan and only declined well beyond the maximum field lifespan. These sex differences were robust to deviations from sex-specific dietary requirements. Our results demonstrate that sexual selection can be at least as important as sex-dependent mortality in shaping the signal of reproductive ageing.

Genetic variation of macronutrient tolerance in Drosophila melanogaster

Publisher: Springer Science and Business Media LLC

Date: 28-03-2022

DOI: 10.1038/S41467-022-29183-X

Abstract: Carbohydrates, proteins and lipids are essential nutrients to all animals however, closely related species, populations, and in iduals can display dramatic variation in diet. Here we explore the variation in macronutrient tolerance in Drosophila melanogaster using the Drosophila genetic reference panel, a collection of ~200 strains derived from a single natural population. Our study demonstrates that D. melanogaster , often considered a “dietary generalist”, displays marked genetic variation in survival on different diets, notably on high-sugar diet. Our genetic analysis and functional validation identify several regulators of macronutrient tolerance, including CG10960/GLUT8 , Pkn and Eip75B . We also demonstrate a role for the JNK pathway in sugar tolerance and de novo lipogenesis. Finally, we report a role for tailles s, a conserved orphan nuclear hormone receptor, in regulating sugar metabolism via insulin-like peptide secretion and sugar-responsive CCHamide-2 expression. Our study provides support for the use of nutrigenomics in the development of personalized nutrition.

Behavioural phase change in the Australian plague locust, Chortoicetes terminifera, is triggered by tactile stimulation of the antennae

Publisher: Elsevier BV

Date: 08-2010

DOI: 10.1016/J.JINSPHYS.2010.04.023

Abstract: Density-dependent phase polyphenism is a defining characteristic of the paraphyletic group of acridid grasshoppers known as locusts. The cues and mechanisms associated with crowding that induce behavioural gregarization are best understood in the desert locust, Schistocerca gregaria, and involve a combination of sensory inputs from the head (visual and olfactory) and mechanostimulation of the hind legs, acting via a transient increase in serotonin in the thoracic ganglia. Since behavioural gregarization has apparently arisen independently multiple times within the Acrididae, the important question arises as to whether the same mechanisms have been recruited each time. Here we explored the roles of visual, olfactory and tactile stimulation in the induction of behavioural gregarization in the Australian plague locust, Chortoicetes terminifera. We show that the primary gregarizing input is tactile stimulation of the antennae, with no evidence for an effect of visual and olfactory stimulation or tactile stimulation of the hind legs. Our results show that convergent behavioural responses to crowding have evolved employing different sites of sensory input in the Australian plague locust and the desert locust.

An oscillation underlying feeding and a number of other behaviours in fifth-instar Locusta migratoria nymphs

Publisher: Wiley

Date: 09-1981

DOI: 10.1111/J.1365-3032.1981.TB00276.X

Effects of crowding, isolation, and transfer from isolation to crowding on total ecdysteroid content of eggs in Schistocerca gregaria

Publisher: Elsevier BV

Date: 07-2004

DOI: 10.1016/J.JINSPHYS.2004.04.008

Temperature, food quality and life history traits of herbivorous insects

Publisher: Elsevier BV

Date: 10-2015

DOI: 10.1016/J.COIS.2015.10.011

Abstract: Population dynamics of herbivorous insects are strongly influenced by temperature and host plant quality an interaction generally thought to be mediated via effects of temperature on metabolic rate and altered energy requirements. However, recent research suggests the relationship between nutrition, temperature, host plant quality and life history traits that influence insect fitness are more complex than appreciated to date. In the laboratory, rates of development are most strongly influenced by temperature, while growth, body composition, and reproductive output are greatly affected by nutrition, notably the uptake of protein and carbohydrate. However, in idual outcomes and consequently population responses in the field are not readily predicted from data on ambient temperatures and host plant chemical composition. The relative amounts of protein and carbohydrate gained from a host plant depends on complex interactions between plant cell structure and leaf chemistry, combined with plasticity in feeding behaviour, microclimate selection, digestive and assimilative physiology. For ex le, grasshoppers can exploit the temperature dependence of host plant quality to maintain nutritional homeostasis. Consequently, understanding environmental interactions such as leaf defences and patterns of foraging, and predicting the effects of climate change on insect populations, will be complex.

Ingestion of resistant starch by mice markedly increases microbiome-derived metabolites

Publisher: Wiley

Date: 29-03-2019

DOI: 10.1096/FJ.201900177R

Assessment and validation of a suite of reverse transcription-quantitative PCR reference genes for analyses of density-dependent behavioural plasticity in the Australian plague locust

Publisher: Springer Science and Business Media LLC

Date: 16-02-2011

DOI: 10.1186/1471-2199-12-7

Testing the Protein Leverage Hypothesis in a free-living human population

Publisher: Elsevier BV

Date: 10-2012

DOI: 10.1016/J.APPET.2012.05.013

Abstract: The Protein Leverage Hypothesis (PLH) predicts that humans prioritize protein when regulating food intake. We tested a central prediction of PLH: protein intake will remain more constant than fat or carbohydrate in the face of dietary changes in a free-living population. Data come from a large s le of adult Filipino women participating in the Cebu Longitudinal Health and Nutrition Survey (CLHNS) located in Philippines. Longitudinal data analysis showed that, as predicted, calories of dietary protein remained more constant over time than calories of dietary carbohydrates or fat, even if corrected for the low proportional contribution of protein to dietary energy.

Regulation of water and macronutrients by the Australian plague locust, Chortoicetes terminifera

Publisher: Elsevier BV

Date: 10-2014

DOI: 10.1016/J.JINSPHYS.2014.06.011

Abstract: Nutritional outcomes for animals are best understood when the intake of multiple nutrients are considered together. The requirements for protein and carbohydrate and the consequences for development, growth and fitness when confined to sub-optimal amounts and ratios of these nutrients are well known for many herbivorous insects. Water is also essential for life, and it is known that herbivorous insects will actively ingest free water, have physiological mechanisms controlling thirst, and suffer fitness consequences if water is excessive or deficient in the diet. As herbivorous insects are thought to obtain the majority of their water from foliage, which can vary in protein, carbohydrate and water content, we investigated if the Australian plague locust, Chortoicetes terminifera, can select among complementary foods to attain a target intake across these three nutrient dimensions. Locusts demonstrated selection behaviour for protein, carbohydrate and water by eating non-randomly from different combinations of complementary foods. A ratio of P:C:H2O of 1:1.13:13.2 or 1(P+C): 6.2 H2O was ingested. Given that locusts strongly regulate water intake, and its importance as an essential resource, we suggest future studies consider the single and interactive influences of water, protein and carbohydrate, when evaluating herbivorous insect host choice and foraging decisions.

Nutritional state and collective motion: from individuals to mass migration

Publisher: The Royal Society

Date: 25-08-2010

DOI: 10.1098/RSPB.2010.1447

Abstract: In order to move effectively in unpredictable or heterogeneous environments animals must make appropriate decisions in response to internal and external cues. Identifying the link between these components remains a challenge for movement ecology and is important in understanding the mechanisms driving both in idual and collective motion. One accessible way of examining how internal state influences an in idual's motion is to consider the nutritional state of an animal. Our experimental results reveal that nutritional state exerts a relatively minor influence on the motion of isolated in iduals, but large group-level differences emerge from diet affecting inter-in idual interactions. This supports the idea that mass movement in locusts may be driven by cannibalism. To estimate how these findings are likely to impact collective migration of locust hopper bands, we create an experimentally parametrized model of locust interactions and motion. Our model supports our hypothesis that nutrient-dependent social interactions can lead to the collective motion seen in our experiments and predicts a transition in the mean speed and the degree of coordination of bands with increasing insect density. Furthermore, increasing the interaction strength (representing greater protein deprivation) dramatically reduces the critical density at which this transition occurs, demonstrating that in iduals' nutritional state could have a major impact on large-scale migration.

Macronutrients and caloric intake in health and longevity

Publisher: Bioscientifica

Date: 28-05-2015

DOI: 10.1530/JOE-15-0173

Abstract: Both lifespan and healthspan are influenced by nutrition, with nutritional interventions proving to be robust across a wide range of species. However, the relationship between nutrition, health and aging is still not fully understood. Caloric restriction is the most studied dietary intervention known to extend life in many organisms, but recently the balance of macronutrients has been shown to play a critical role. In this review, we discuss the current understanding regarding the impact of calories and macronutrient balance in mammalian health and longevity, and highlight the key nutrient-sensing pathways that mediate the effects of nutrition on health and ageing.

Anoxia tolerance of the adult Australian Plague Locust (Chortoicetes terminifera)

Publisher: Elsevier BV

Date: 03-2019

DOI: 10.1016/J.CBPA.2018.12.005

Abstract: Optimal breeding conditions for locust swarms often include heavy rainfall and flooding, exposing in iduals to the risk of immersion and anoxia. We investigated anoxia tolerance in solitarious and gregarious adults of the Australian Plague Locust, Chortoicetes terminifera, by measuring the time to enter an anoxic coma after submersion in water, the time for recovery of ventilation and the ability to stand on return to air. We found a longer time to succumb in immature adults that we attribute to a larger tracheal volume. Time to succumb was also longer after autotomizing the hindlegs to reduce the energetic cost of muscular activity. Time to recover was longer in gregarious males and this developed during maturation, suggesting an increase in the cost of neural processing associated with social interactions under crowded conditions. Short-term changes in rearing conditions had effects that we interpret as stress responses, potentially mediated by octopamine.

Development of fly tolerance to consuming a high-protein diet requires physiological, metabolic and transcriptional changes

Publisher: Springer Science and Business Media LLC

Date: 29-05-2020

DOI: 10.1007/S10522-020-09880-0

Estimating Niche width using stable isotopes in the face of habitat variability: A modelling case study in the marine environment

Publisher: Public Library of Science (PLoS)

Date: 02-08-2012

DOI: 10.1371/JOURNAL.PONE.0040539

MALE COCKROACHES PREFER A HIGH CARBOHYDRATE DIET THAT MAKES THEM MORE ATTRACTIVE TO FEMALES: IMPLICATIONS FOR THE STUDY OF CONDITION DEPENDENCE

Publisher: Wiley

Date: 15-02-2011

DOI: 10.1111/J.1558-5646.2011.01233.X

Abstract: Sexual selection is a major force driving the evolution of elaborate male sexual traits. Handicap models of sexual selection predict that male sexual traits should covary positively with condition, making them reliable indicators of male quality. However, most studies have either manipulated condition through varying diet quantity and/or caloric content without knowledge of specific nutrient effects or have correlated proxies of condition with sexual trait expression. We used nutritional geometry to quantify protein and carbohydrate intake by male cockroaches, Nauphoeta cinerea, and related this to sex pheromone expression, attractiveness, and dominance status. We found that carbohydrate, but not protein, intake is related to male sex pheromone expression and attractiveness but not dominance status. Additionally, we related two condition proxies (weight gain and lipid reserves) to protein and carbohydrate acquisition. Weight gain increased with the intake of both nutrients, whereas lipid reserves only increased with carbohydrate intake. Importantly, lipid accumulation was not as responsive to carbohydrate intake as attractiveness and thus was a less-accurate condition proxy. Moreover, males preferentially consumed high carbohydrate diets with little regard for protein content suggesting that they actively increase their carbohydrate intake thereby maximizing their reproductive fitness by being attractive.

Does diet influence aging? Evidence from animal studies

Publisher: Wiley

Date: 24-06-2022

DOI: 10.1111/JOIM.13530

Abstract: Nutrition profoundly influences the risk for many age‐related diseases. Whether nutrition influences human aging biology directly is less clear. Studies in different animal species indicate that reducing food intake (“caloric restriction” [CR]) can increase lifespan and delay the onset of diseases and the biological hallmarks of aging. Obesity has been described as “accelerated aging” and therefore the lifespan and health benefits generated by CR in both aging and obesity may occur via similar mechanisms. Beyond calorie intake, studies based on nutritional geometry have shown that protein intake and the interaction between dietary protein and carbohydrates influence age‐related health and lifespan. Studies where animals are calorically restricted by providing free access to diluted diets have had less impact on lifespan than those studies where animals are given a reduced aliquot of food each day and are fasting between meals. This has drawn attention to the role of fasting in health and aging, and exploration of the health effects of various fasting regimes. Although definitive human clinical trials of nutrition and aging would need to be unfeasibly long and unrealistically controlled, there is good evidence from animal experiments that some nutritional interventions based on CR, manipulating dietary macronutrients, and fasting can influence aging biology and lifespan.

Internal consistency and convergent and divergent validity of the Liverpool jetlag questionnaire

Publisher: Informa UK Limited

Date: 14-01-2020

DOI: 10.1080/07420528.2019.1704771

Abstract: Objective measures of circadian disruption are difficult to capture in a free-living environment hence the importance of validating subjective measures of jetlag. We aimed to assess the internal consistency of the 15-item Liverpool Jetlag Scale and its convergent and ergent validity with indicators of fatigue and anxiety in a large s le of air passengers. Online survey of passengers was conducted after travel on a range of long-haul flights. Jetlag was captured using the Liverpool scale, fatigue was measured using the Vitality subscale of the Short-Form Health Survey (SF-36), and the presence of anxiety or worry before, during, and after flight was self-reported. Inter-item correlations and Cronbach's alpha were calculated to assess the internal consistency of the scale. Exploratory factor analysis was used to examine whether the scale was consistent with one underlying construct of circadian disruption. Correlations between fatigue and anxiety (flying, situational, symptoms) with jetlag were used to assess convergent and ergent validity. Linear regression was used to determine the most important symptoms contributing to subjective jetlag rating. N = 460 passengers (57% female, mean age 50, SD 16 years) were surveyed. Cronbach's alpha indicated high internal reliability (alpha = 0.85). Jetlag was more strongly correlated with fatigue (rho = 0.47) than any type of anxiety (rho = 0.10-0.22). Exploratory factor analysis indicated responses were consistent with four factors: (i) fatigue/daytime impairment, (ii) sleep disturbance, (iii) changes in appetite and (iv) changes in bowel function. Regression analysis indicated that only changes in concentration, sleep time, fatigue, sleep quality and frequency of bowel motions were independent correlates of subjective jetlag (R

A Comparison of the Australian Dietary Guidelines to the NOVA Classification System in Classifying Foods to Predict Energy Intakes and Body Mass Index

Publisher: MDPI AG

Date: 23-09-2022

DOI: 10.3390/NU14193942

Abstract: NOVA classification distinguishes foods by level of processing, with evidence suggesting that a high intake of ultra-processed foods (UPFs, NOVA category 4) leads to obesity. The Australian Dietary Guidelines, in contrast, discourage excess consumption of “discretionary foods” (DFs), defined according to their composition. Here, we (i) compare the classification of Australian foods under the two systems, (ii) evaluate their performance in predicting energy intakes and body mass index (BMI) in free-living Australians, and (iii) relate these outcomes to the protein leverage hypothesis of obesity. Secondary analysis of the Australian National Nutrition and Physical Activity Survey was conducted. Non-protein energy intake increased by 2.1 MJ (p 0.001) between lowest and highest tertiles of DF intake, which was significantly higher than UPF (0.6 MJ, p 0.001). This demonstrates that, for Australia, the DF classification better distinguishes foods associated with high energy intakes than does the NOVA system. BMI was positively associated with both DFs (−1. 0, p = 0.0001) and UPFs (−1.1, p = 0.0001) consumption, with no difference in strength of association. For both classifications, macronutrient and energy intakes conformed closely to the predictions of protein leverage. We account for the similarities and differences in performance of the two systems in an analysis of Australian foods.

Balancing of specific nutrients and subsequent growth and body composition in the slug Arion lusitanicus

Publisher: Elsevier BV

Date: 10-2013

DOI: 10.1016/J.PHYSBEH.2013.08.023

Abstract: Feeding generalists typically occupy broad ecological niches and so are potentially pre-adapted to a range of novel food objects. In northern Europe, the slug Arion lusitanicus has spread rapidly as an invasive species and a serious horticultural and agricultural pest. We used nutritional geometry to analyze nutrient balancing capabilities and consequences for performance in A. lusitanicus when provided with one of three nutritionally fixed diets or when given dietary choice. The slugs over-ingested high amounts of the most abundant nutrient in order to get more of the limited nutrient. However, they regulated protein intake more tightly than carbohydrate intake resulting in a very high food intake when fed a protein-poor diet. Growth and body composition were highly affected by the nutrient balance of their diet. When given the choice to feed from two nutritionally different diets, the slugs selected an intake balance of protein and carbohydrate with sufficient precision to maximize growth. Nutrient utilization efficiency increased with increasing deficiency of the specific nutrient in the diet. Ingested carbohydrate was more efficiently stored as lipid in slugs fed more carbohydrate-poor diets, and ingested nitrogen was more efficiently incorporated into slug bodies in slugs fed more protein-poor diets. Our experiments suggest that the evolved behavioral and physiological regulatory capacities of A. lusitanicus may explain some of the success that this slug experiences as an invasive species. We furthermore propose that invasive species might be more dependent on high protein availability in the environment than non-invasive species.

Protein Leverage: Theoretical Foundations and Ten Points of Clarification

Publisher: Wiley

Date: 24-07-2019

DOI: 10.1002/OBY.22531

Abstract: Much attention has been focused on fats and carbohydrates as the nutritional causes of energy overconsumption and obesity. In 2003, a model of intake regulation was proposed in which the third macronutrient, protein, is not only involved but is a primary driver of calorie intake via its interactions with carbohydrates and fats. This model, called protein leverage, posits that the strong regulation of protein intake causes the overconsumption of fats and carbohydrates (hence total energy) on diets with a low proportion of energy from protein and their underconsumption on diets with a high proportion of protein. Protein leverage has since been demonstrated in a range of animal studies and in several studies of human macronutrient regulation, and its potential role in contributing to the obesity epidemic is increasingly attracting discussion. Over recent years, however, several misconceptions about protein leverage have arisen. Our aim in this paper is to briefly outline some key aspects of the underlying theory and clarify 10 points of misunderstanding that have the potential to ert attention from the substantive issues.

Design and testing of foods differing in protein to energy ratios

Publisher: Elsevier BV

Date: 10-2010

DOI: 10.1016/J.APPET.2010.06.009

Abstract: Our aim was to design a selection of foods with differing proportions of protein but equal palatability in two settings, Sydney Australia and Kingston Jamaica. The foods were manipulated to contain 10, 15 or 25% E as protein with reciprocal changes in carbohydrate to 60, 55 or 45% E and dietary fat was kept constant at 30%. Naïve participants did not identify a difference in protein between the versions. On average, the versions were rated equal in pleasantness (Sydney-10%: 44±2, 15%: 49±2 and 25%: 49±2 Kingston-10%: 41±3, 15%: 41±3 and 25%: 37±3).

Effects of dietary protein to carbohydrate balance on energy intake, fat storage, and heat production in mice

Publisher: Wiley

Date: 2013

DOI: 10.1002/OBY.20007

Abstract: Protein leverage plays a role in driving increased energy intakes that may promote weight gain. The influence of the protein to carbohydrate ratio (P:C) in diets of C57BL/6J mice on total energy intake, fat storage, and thermogenesis was investigated. Male mice (9 weeks old) were provided ad libitum access to one of five isocaloric diets that differed in P:C. Food intake was recorded for 12 weeks. After 16 weeks, white adipose tissue (WAT) and brown adipose tissue (BAT) deposits were dissected, weighed, and the expression levels of key metabolic regulators were determined in BAT. In a separate cohort, body surface temperature was measured in response to 25 diets differing in protein, fat, and carbohydrate content. Mice on low P:C diets (9:72 and 17:64) had greater total energy intake and increased WAT and BAT stores. Body surface temperature increased with total energy intake and with protein, fat, and carbohydrate, making similar contributions per kJ ingested. Expression of three key regulators of thermogenesis were downregulated in BAT in mice on the lowest P:C diet. Low-protein diets induced sustained hyperphagia and a generalized expansion of fat stores. Increased body surface temperature on low P:C diets was consistent with diet-induced thermogenesis (DIT) as a means to dissipate excess ingested energy on such diets, although this was not sufficient to prevent development of increased adiposity. Whether BAT was involved in DIT is not clear. Increased BAT mass on low P:C diets might suggest so, but patterns of thermogenic gene expression do not support a role for BAT in DIT, although they might reflect failure of thermogenic function with prolonged exposure to a low P:C diet.

A rapid, precise and low‐cost method to quantify silicon for the determination of food intake and utilisation for insect herbivores

Publisher: Wiley

Date: 30-03-2018

DOI: 10.1111/AEN.12335

Nutrition, anxiety and hormones. Why sex differences matter in the link between obesity and behavior.

Publisher: Elsevier BV

Date: 04-2022

DOI: 10.1016/J.PHYSBEH.2022.113713

Abstract: Obesity and mood disorders are two of the most serious health issues of modern times. These health conditions are often linked, with obesity acting both as a cause and consequence of anxiety and depression. Although sex differences in the relationship between obesity and mood disorders are observed in clinical populations, the relative influence of biology versus societal conditioning is unclear. In part, this is because sex effects are rarely examined in the animal models used to derive our understanding of basic biological mechanisms. Due to the perceived confounding nature of hormonal fluctuations in females, rodent studies examining nutritional effects on behavioral responses are typically restricted to males. Yet, hormones play an important role in mediating effects of diet on behavior. In this mini-review, we outline interactions between obesity, hormones and the brain to illustrate the importance of considering sex-specific effects in studies of nutritional effects on behavior. We highlight the need for a more nuanced understanding of how dietary factors influence these relationships, arguing that such knowledge will help improve clinical health outcomes in the management of both obesity and mood disorders.

Swarm formation in the desert locust Schistocerca gregaria:isolation and NMR analysis of the primary maternal gregarizing agent

Publisher: The Company of Biologists

Date: 02-2008

DOI: 10.1242/JEB.013458

Abstract: Depending on their rearing density, female desert locusts Schistocerca gregaria epigenetically endow their offspring with differing phenotypes. To identify the chemical basis for such maternal transmission, we compared solitarious and gregarious locust egg pod foam using high performance liquid chromatography (HPLC). We revealed causal relationships between foam chemistry and hatchling phenotype (phase state) by iteratively applying HPLC fractions from gregarious locust egg foam extracts to solitarious eggs and assessing resulting hatchlings with a behavioural bioassay involving logistic regression. Selection and application of increasingly specific HPLC fractions allowed us to isolate compounds with gregarizing properties. Hatchling gregarization was triggered only by certain fractions and was dose dependent. In a final series of experiments, we characterized the most specific gregarizing fraction by nuclear magnetic resonance (NMR) spectroscopy. Here we present tentative structural features of the primary locust maternal gregarizing agent, which appears to be an alkylated l-dopa analogue. In addition, we propose a mechanism for phase-dependent regulation of this compound's activity.

Protein-leverage in mice: The Geometry of macronutrient balancing and consequences for fat deposition

Publisher: Wiley

Date: 03-2008

DOI: 10.1038/OBY.2007.58

Abstract: The Protein-Leverage Hypothesis proposes that humans regulate their intake of macronutrients and that protein intake is prioritized over fat and carbohydrate intake, causing excess energy ingestion when diets contain low %protein. Here we test in a model animal, the mouse: (i) the extent to which intakes of protein and carbohydrate are regulated (ii) if protein intake has priority over carbohydrates so that unbalanced foods low in %protein leads to increased energy intake and (iii) how such variations in energy intake are converted into growth and storage. We fed mice one of five isocaloric foods having different protein to carbohydrate composition, or a combination of two of these foods (N = 15). Nutrient intake and corresponding growth in lean body mass and lipid mass were measured. Data were analyzed using a geometric approach for analyzing intake of multiple nutrients. (i) Mice fed different combinations of complementary foods regulated their intake of protein and carbohydrate toward a relatively well-defined intake target. (ii) When mice were offered diets with fixed protein to carbohydrate ratio, they regulated the intake of protein more strongly than carbohydrate. This protein-leverage resulted in higher energy consumption when diets had lower %protein and led to increased lipid storage in mice fed the diet containing the lowest %protein. Although the protein-leverage in mice was less than what has been proposed for humans, energy intakes were clearly higher on diets containing low %protein. This result indicates that tight protein regulation can be responsible for excess energy ingestion and higher fat deposition when the diet contains low %protein.

Adequacy of nutritional intake among older men living in Sydney, Australia: findings from the Concord Health and Ageing in Men Project (CHAMP)

Publisher: Cambridge University Press (CUP)

Date: 12-08-2015

DOI: 10.1017/S0007114515002421

Abstract: Previous research shows that older men tend to have lower nutritional intakes and higher risk of under-nutrition compared with younger men. The objectives of this study were to describe energy and nutrient intakes, assess nutritional risk and investigate factors associated with poor intake of energy and key nutrients in community-dwelling men aged ≥75 years participating in the Concord Health and Ageing in Men Project – a longitudinal cohort study on older men in Sydney, Australia. A total of 794 men (mean age 81·4 years) had a detailed diet history interview, which was carried out by a dietitian. Dietary adequacy was assessed by comparing median intakes with nutrient reference values (NRV): estimated average requirement, adequate intake or upper level of intake. Attainment of NRV of total energy and key nutrients in older age (protein, Fe, Zn, riboflavin, Ca and vitamin D) was incorporated into a ‘key nutrients’ variable dichotomised as ‘good’ (≥5) or ‘poor’ (≤4). Using logistic regression modelling, we examined associations between key nutrients with factors known to affect food intake. Median energy intake was 8728 kJ (P5=5762 kJ, P95=12 303 kJ), and mean BMI was 27·7 ( sd 4·0) kg/m 2 . Men met their NRV for most nutrients. However, only 1 % of men met their NRV for vitamin D, only 19 % for Ca, only 30 % for K and only 33 % for dietary fibre. Multivariate logistic regression analysis showed that only country of birth was significantly associated with poor nutritional intake. Dietary intakes were adequate for most nutrients however, only half of the participants met the NRV of ≥5 key nutrients.

Lifespan and reproduction in Drosophila : New insights from nutritional geometry

Publisher: Proceedings of the National Academy of Sciences

Date: 19-02-2008

DOI: 10.1073/PNAS.0710787105

Abstract: Modest dietary restriction (DR) prolongs life in a wide range of organisms, spanning single-celled yeast to mammals. Here, we report the use of recent techniques in nutrition research to quantify the detailed relationship between diet, nutrient intake, lifespan, and reproduction in Drosophila melanogaster . Caloric restriction (CR) was not responsible for extending lifespan in our experimental flies. Response surfaces for lifespan and fecundity were maximized at different protein–carbohydrate intakes, with longevity highest at a protein-to-carbohydrate ratio of 1:16 and egg-laying rate maximized at 1:2. Lifetime egg production, the measure closest to fitness, was maximized at an intermediate P:C ratio of 1:4. Flies offered a choice of complementary foods regulated intake to maximize lifetime egg production. The results indicate a role for both direct costs of reproduction and other deleterious consequences of ingesting high levels of protein. We unite a body of apparently conflicting work within a common framework and provide a platform for studying aging in all organisms.

Macronutrient balance mediates trade‐offs between immune function and life history traits

Publisher: Wiley

Date: 19-08-2010

DOI: 10.1111/J.1365-2435.2010.01766.X

The power of protein

Publisher: Elsevier BV

Date: 07-2020

DOI: 10.1093/AJCN/NQAA088

Macronutrients modulate survival to infection and immunity in Drosophila

Publisher: Wiley

Date: 09-12-2019

DOI: 10.1111/1365-2656.13126

Sexual repurposing of juvenile aposematism in locusts

Publisher: Proceedings of the National Academy of Sciences

Date: 15-08-2022

DOI: 10.1073/PNAS.2200759119

Abstract: Adaptive plasticity requires an integrated suite of functional responses to environmental variation, which can include social communication across life stages. Desert locusts ( Schistocerca gregaria ) exhibit an extreme ex le of phenotypic plasticity called phase polyphenism, in which a suite of behavioral and morphological traits differ according to local population density. Male and female juveniles developing at low population densities exhibit green- or sand-colored background-matching camouflage, while at high densities they show contrasting yellow and black aposematic patterning that deters predators. The predominant background colors of these phenotypes (green/sand/yellow) all depend on expression of the carotenoid-binding “Yellow Protein” ( YP ). Gregarious (high-density) adults of both sexes are initially pinkish, before a YP -mediated yellowing reoccurs upon sexual maturation. Yellow color is especially prominent in gregarious males, but the reason for this difference has been unknown since phase polyphenism was first described in 1921. Here, we use RNA interference to show that gregarious male yellowing acts as an intrasexual warning signal, which forms a multimodal signal with the antiaphrodisiac pheromone phenylacetonitrile (PAN) to prevent mistaken sexual harassment from other males during scramble mating in a swarm. Socially mediated reexpression of YP thus adaptively repurposes a juvenile signal that deters predators into an adult signal that deters undesirable mates. These findings reveal a previously underappreciated sexual dimension to locust phase polyphenism, and promote locusts as a model for investigating the relative contributions of natural versus sexual selection in the evolution of phenotypic plasticity.

Diet mediates the relationship between longevity and reproduction in mammals

Publisher: Springer Science and Business Media LLC

Date: 12-01-2012

DOI: 10.1007/S11357-011-9380-8

The diet and the damage done

Publisher: Springer Science and Business Media LLC

Date: 21-10-2019

DOI: 10.1038/S42255-019-0128-6

A behavioural analysis of phase change in the desert locust

Publisher: Wiley

Date: 11-1999

DOI: 10.1111/J.1469-185X.1999.TB00038.X

LC-N2G: a local consistency approach for nutrigenomics data analysis

Publisher: Springer Science and Business Media LLC

Date: 17-11-2020

DOI: 10.1186/S12859-020-03861-3

Abstract: Nutrigenomics aims at understanding the interaction between nutrition and gene information. Due to the complex interactions of nutrients and genes, their relationship exhibits non-linearity. One of the most effective and efficient methods to explore their relationship is the nutritional geometry framework which fits a response surface for the gene expression over two prespecified nutrition variables. However, when the number of nutrients involved is large, it is challenging to find combinations of informative nutrients with respect to a certain gene and to test whether the relationship is stronger than chance. Methods for identifying informative combinations are essential to understanding the relationship between nutrients and genes. We introduce Local Consistency Nutrition to Graphics (LC-N2G), a novel approach for ranking and identifying combinations of nutrients with gene expression. In LC-N2G, we first propose a model-free quantity called Local Consistency statistic to measure whether there is non-random relationship between combinations of nutrients and gene expression measurements based on (1) the similarity between s les in the nutrient space and (2) their difference in gene expression. Then combinations with small LC are selected and a permutation test is performed to evaluate their significance. Finally, the response surfaces are generated for the subset of significant relationships. Evaluation on simulated data and real data shows the LC-N2G can accurately find combinations that are correlated with gene expression. The LC-N2G is practically powerful for identifying the informative nutrition variables correlated with gene expression. Therefore, LC-N2G is important in the area of nutrigenomics for understanding the relationship between nutrition and gene expression information.

Integrating nutrients, foods, diets, and appetites with obesity and cardiometabolic health

Publisher: Wiley

Date: 10-08-2015

DOI: 10.1002/OBY.21214

The gastrointestinal tract as a nutrient-balancing organ

Publisher: The Royal Society

Date: 03-02-2010

DOI: 10.1098/RSPB.2009.2045

Abstract: Failure to provision tissues with an appropriate balance of nutrients engenders fitness costs. Maintaining nutrient balance can be achieved by adjusting the selection and consumption of foods, but this may not be possible when the nutritional environment is limiting. Under such circumstances, rebalancing of an imbalanced nutrient intake requires post-ingestive mechanisms. The first stage at which such post-ingestive rebalancing might occur is within the gastrointestinal tract (GIT), by differential release of digestive enzymes—releasing less of those enzymes for nutrients present in excess while maintaining or boosting levels of enzymes for nutrients in deficit. Here, we use an insect herbivore, the locust, to show for the first time that such compensatory responses occur within the GIT. Furthermore, we show that differential release of proteases and carbohydrases in response to nutritional state translate into differential extraction of macronutrients from host plants. The prevailing view is that physiological and structural plasticity in the GIT serves to maximize the rate of nutrient gain in relation to costs of maintaining the GIT our findings show that GIT plasticity is integral to the maintenance of nutrient balance.

Behavioural phase polyphenism in the Australian plague locust ( Chortoicetes terminifera )

Publisher: The Royal Society

Date: 04-03-2009

DOI: 10.1098/RSBL.2008.0764

Abstract: Swarming and the expression of phase polyphenism are defining characteristics of locust species. Increases in local population density mediate morphological, physiological and behavioural changes within in iduals, which correlate with mass marching of juveniles in migratory bands and flying swarms of adults. The Australian plague locust ( Chortoicetes terminifera ) regularly forms migratory bands and swarms, but is claimed not to express phase polyphenism and has accordingly been used to argue against a central role for phase change in locust swarming. We demonstrate that juvenile C. terminifera express extreme density-dependent behavioural phase polyphenism. Isolated-reared juveniles are sedentary and repelled by conspecifics, whereas crowd-reared in iduals are highly active and are attracted to conspecifics. In contrast to other major locust species, however, behavioural phase change does not accumulate across generations, but shifts completely within an in idual's lifetime in response to a change in population density.

Ant Foragers Compensate for the Nutritional Deficiencies in the Colony

Publisher: Elsevier BV

Date: 2020

DOI: 10.1016/J.CUB.2019.11.019

Abstract: Achieving nutritional homeostasis is crucial for the fitness of all living organisms [1]. Using "collective wisdom," ants have been shown to excel at making rapid and appropriate decisions under various contexts [2, 3], including foraging [4-7]. Ants often use pheromone trails to share information about food resources [8-10], a process allowing them to focus their foraging activity on the best food source available [7, 11-14]. However, what constitutes the best food source depends on the nutritional context of the colony in relation to its food environment [15]. In this study, we exposed ant colonies to various nutrient deficiencies and observed their compensatory nutritional responses. Ants were deprived of carbohydrate, sterol, protein, a subset of amino acids, or a single amino acid. We found that ants were rapidly able to match their foraging decisions to their nutritional needs, even if the deficiency concerned a single amino acid. An in idual-based model demonstrates that these impressive feats of nutritional compensation can emerge from the iterative process of trail-laying behavior, which relies on a simple in idual decision: to eat or not to eat. Our results show that, by adjusting their feeding behavior at the in idual level, ants sustain homeostasis at the colony level.

Crowded locusts produce hatchlings vulnerable to fungal attack

Publisher: The Royal Society

Date: 12-08-2009

DOI: 10.1098/RSBL.2009.0495

Abstract: Transgenerational effects of parental experience on offspring immunity are well documented in the vertebrate literature (where antibodies play an obligatory role), but have only recently been described in invertebrates. We have assessed the impact of parental rearing density upon offspring disease resistance by challenging day-old locust hatchlings ( Schistocerca gregaria ) from either crowd- or solitary-reared parents with the fungal pathogen Metarhizium anisopliae var. acridum . When immersed in standardized conidia suspensions, hatchlings from gregarious parents suffered greater pathogen-induced mortality than hatchlings from solitary-reared parents. This observation contradicts the basic theory of positive density-dependent prophylaxis and demonstrates that crowding has a transgenerational influence upon locust disease resistance.

Modelling the ecological niche from functional traits

Publisher: The Royal Society

Date: 12-11-2010

DOI: 10.1098/RSTB.2010.0034

Abstract: The niche concept is central to ecology but is often depicted descriptively through observing associations between organisms and habitats. Here, we argue for the importance of mechanistically modelling niches based on functional traits of organisms and explore the possibilities for achieving this through the integration of three theoretical frameworks: biophysical ecology (BE), the geometric framework for nutrition (GF) and dynamic energy budget (DEB) models. These three frameworks are fundamentally based on the conservation laws of thermodynamics, describing energy and mass balance at the level of the in idual and capturing the prodigious predictive power of the concepts of ‘homeostasis’ and ‘evolutionary fitness’. BE and the GF provide mechanistic multi-dimensional depictions of climatic and nutritional niches, respectively, providing a foundation for linking organismal traits (morphology, physiology, behaviour) with habitat characteristics. In turn, they provide driving inputs and cost functions for mass/energy allocation within the in idual as determined by DEB models. We show how integration of the three frameworks permits calculation of activity constraints, vital rates (survival, development, growth, reproduction) and ultimately population growth rates and species distributions. When integrated with contemporary niche theory, functional trait niche models hold great promise for tackling major questions in ecology and evolutionary biology.

Determining the metabolic effects of dietary fat, sugars and fat-sugar interaction using nutritional geometry in a dietary challenge study with male mice

Publisher: Springer Science and Business Media LLC

Date: 21-07-2023

DOI: 10.1038/S41467-023-40039-W

Abstract: The metabolic effects of sugars and fat lie at the heart of the “carbohydrate vs fat” debate on the global obesity epidemic. Here, we use nutritional geometry to systematically investigate the interaction between dietary fat and the major monosaccharides, fructose and glucose, and their impact on body composition and metabolic health. Male mice (n = 245) are maintained on one of 18 isocaloric diets for 18–19 weeks and their metabolic status is assessed through in vivo procedures and by in vitro assays involving harvested tissue s les. We find that in the setting of low and medium dietary fat content, a 50:50 mixture of fructose and glucose (similar to high-fructose corn syrup) is more obesogenic and metabolically adverse than when either monosaccharide is consumed alone. With increasing dietary fat content, the effects of dietary sugar composition on metabolic status become less pronounced. Moreover, higher fat intake is more harmful for glucose tolerance and insulin sensitivity irrespective of the sugar mix consumed. The type of fat consumed (soy oil vs lard) does not modify these outcomes. Our work shows that both dietary fat and sugars can lead to adverse metabolic outcomes, depending on the dietary context. This study shows how the principles of the two seemingly conflicting models of obesity (the “energy balance model” and the “carbohydrate insulin model”) can be valid, and it will help in progressing towards a unified model of obesity. The main limitations of this study include the use of male mice of a single strain, and not testing the metabolic effects of fructose intake via sugary drinks, which are strongly linked to human obesity.

Evolution: Radiotracking Sexual Selection

Publisher: Elsevier BV

Date: 10-2008

DOI: 10.1016/J.CUB.2008.08.055

Abstract: Why are members of one sex bigger than those of the other? A new study in which male giant weta were radiotracked found that smaller, longer legged males win the race to inseminate females.

Cardio-metabolic consequences of dietary carbohydrates: Reconciling contradictions using nutritional geometry

Publisher: Oxford University Press (OUP)

Date: 09-05-2021

DOI: 10.1093/CVR/CVAA136

Abstract: Carbohydrates are the major source of dietary energy, but their role in health and disease remains controversial. Recent epidemiological evidence suggests that the increased consumption of carbohydrates is associated with obesity and increased risk of mortality and dietary trials show that carbohydrate restriction leads to weight loss and improved glycaemic status in obese and diabetic subjects. In contrast, the diets of populations with long and healthy lifespans (e.g. traditional Okinawans from Japan) are high in carbohydrate and low in protein, and several clinical and preclinical studies have linked low-carbohydrate–high-protein diets with increased mortality risk. In this paper we attempt to reconcile these contradictory findings by moving beyond traditional single-nutrient analyses to consider the interactions between nutrients on health outcomes. We do so using the Geometric Framework (GF), a nutritional modelling platform that explicitly considers the main and interactive effects of multiple nutrients on phenotypic characteristics. Analysis of human data by GF shows that weight loss and improved cardio-metabolic outcomes under carbohydrate restriction derive at least in part from reduced caloric intake due to the concomitantly increased proportion of protein in the diet. This is because, as in many animals, a specific appetite for protein is a major driver of food intake in humans. Conversely, dilution of protein in the diet leverages excess food intake through compensatory feeding for protein (‘protein leverage’). When protein is diluted in the diet by readily digestible carbohydrates and fats, as is the case in modern ultra-processed foods, protein leverage results in excess calorie intake, leading to rising levels of obesity and metabolic disease. However, when protein is diluted in the diet by increased quantities of less readily digestible forms of carbohydrate and fibre, energy balance is maintained and health benefits accrue, especially during middle age and early late-life. We argue that other controversies in carbohydrate research can be resolved using the GF methodology in dietary studies.

Aging Biology and Novel Targets for Drug Discovery

Publisher: Oxford University Press (OUP)

Date: 21-06-2012

DOI: 10.1093/GERONA/GLR095

Nutritional and metabolic regulation of the metabolite dimethylguanidino valeric acid: an early marker of cardiometabolic disease

Publisher: American Physiological Society

Date: 09-2020

DOI: 10.1152/AJPENDO.00207.2020

Abstract: Dimethylguanidino valeric acid (DMGV) is a marker of fatty liver disease, incident coronary artery disease, cardiovascular mortality, and incident diabetes. Recently, it was reported that circulating DMGV levels correlated positively with consumption of sugary beverages and negatively with intake of fruits and vegetables in three Swedish community-based cohorts. Here, we validate these results in the Framingham Heart Study Third Generation Cohort. Furthermore, in mice, diets rich in sucrose or fat significantly increased plasma DMGV concentrations. DMGV is the product of metabolism of asymmetric dimethylarginine (ADMA) by the hepatic enzyme AGXT2. ADMA can also be metabolized to citrulline by the cytoplasmic enzyme DDAH1. We report that a high-sucrose diet induced conversion of ADMA exclusively into DMGV (supporting the relationship with sugary beverage intake in humans), while a high-fat diet promoted conversion of ADMA to both DMGV and citrulline. On the contrary, replacing dietary native starch with high-fiber-resistant starch increased ADMA concentrations and induced its conversion to citrulline, without altering DMGV concentrations. In a cohort of obese nondiabetic adults, circulating DMGV concentrations increased and ADMA levels decreased in those with either liver or muscle insulin resistance. This was similar to changes in DMGV and ADMA concentrations found in mice fed a high-sucrose diet. Sucrose is a disaccharide of glucose and fructose. Compared with glucose, incubation of hepatocytes with fructose significantly increased DMGV production. Overall, we provide a comprehensive picture of the dietary determinants of DMGV levels and association with insulin resistance.

Impact of dietary macronutrient composition on gene regulation in adipose tissue

Publisher: Research Square Platform LLC

Date: 04-08-2023

DOI: 10.21203/RS.3.RS-2973236/V1

Abstract: Diet is a key lifestyle component that influences metabolic health through several factors, including total energy intake and macronutrient composition. While the impact of caloric intake on gene expression and physiological phenomenon in various tissues is well described, the influence of dietary macronutrient composition on these parameters is less well studied. Here, we used the Nutritional Geometry framework to investigate the role of macronutrient composition on metabolic function and gene regulation in adipose tissue. Using ten isocaloric diets that vary systematically in their proportion of energy from fat, protein, and carbohydrates, we found that gene expression and splicing are highly responsive to macronutrient composition, with distinct sets of genes regulated by different macronutrient interactions. Specifically, the expression of many genes associated with Bardet-Biedl syndrome was responsive to dietary fat content. Splicing and expression changes occurred in largely separate gene sets, highlighting distinct mechanisms by which dietary composition influences the transcriptome and emphasizing the importance of considering splicing changes to more fully capture the gene regulation response to environmental changes such as diet. Our study provides insight into the gene regulation plasticity of adipose tissue in response to macronutrient composition, beyond the already well-characterized response to caloric intake.

Nutritional PharmEcology: Doses, nutrients, toxins, and medicines

Publisher: Oxford University Press (OUP)

Date: 07-2009

DOI: 10.1093/ICB/ICP050

Abstract: The synthesis of pharmacological techniques and concepts into ecology holds considerable promise for gaining new insights into old questions, uncovering new priorities for research and, ultimately, for consolidating a new sub-discipline within the ecological sciences-PharmEcology. We argue that this potential will best be realized if the boundaries of PharmEcology are drawn broadly to encompass not only toxins and medicines, but also nutrients. The hub of our argument is that PharmEcology shares with the established discipline of nutritional ecology an organismal focus, at the core of which is the notion of evolutionary function. From this functional viewpoint the iding lines between chemicals traditionally considered as "toxins," "medicines," and "nutrients" are often thin, vague, heavily contingent and non-stationary, and thus provide a poor footing for an emerging sub-discipline. We build our argument around three points: nutrients and toxins are not so different, medicines and nutrients are not so different, and even in cases in which nutrients, medicines and toxins can be categorically distinguished, the biological actions of these compounds are heavily interdependent.

Anisotropic Interaction and Motion States of Locusts in a Hopper Band

Publisher: Cold Spring Harbor Laboratory

Date: 11-2021

DOI: 10.1101/2021.10.29.466390

Abstract: Swarming locusts present a quintessential ex le of animal collective motion. Juvenile locusts march and hop across the ground in coordinated groups called hopper bands. Composed of up to millions of insects, hopper bands exhibit coordinated motion and various collective structures. These groups are well-documented in the field, but the in idual insects themselves are typically studied in much smaller groups in laboratory experiments. We present the first trajectory data that detail the movement of in idual locusts within a hopper band in a natural setting. Using automated video tracking, we derive our data from footage of four distinct hopper bands of the Australian plague locust, Chortoicetes terminifera . We reconstruct nearly twentythousand in idual trajectories composed of over 3.3 million locust positions. We classify these data into three motion states: stationary, walking, and hopping. Distributions of relative neighbor positions reveal anisotropies that depend on motion state. Stationary locusts have high-density areas distributed around them apparently at random. Walking locusts have a low-density area in front of them. Hopping locusts have low-density areas in front and behind them. Our results suggest novel interactions, namely that locusts change their motion to avoid colliding with neighbors in front of them.

Dysbiosis in imiquimod-induced psoriasis alters gut immunity and exacerbates colitis development

Publisher: Elsevier BV

Date: 08-2022

DOI: 10.1016/J.CELREP.2022.111191

Abstract: Psoriasis has long been associated with inflammatory bowel disease (IBD) however, a causal link is yet to be established. Here, we demonstrate that imiquimod-induced psoriasis (IMQ-pso) in mice disrupts gut homeostasis, characterized by increased proportions of colonic CX

Behavioural correlates of phenotypic plasticity in mouthpart chemoreceptor numbers in locusts

Publisher: Elsevier BV

Date: 08-2004

DOI: 10.1016/J.JINSPHYS.2004.05.010

An integrative approach to dietary balance across the life course

Publisher: Elsevier BV

Date: 05-2022

DOI: 10.1016/J.ISCI.2022.104315

MasterChef recipes and takeaway foods: How do they compare?

Publisher: Elsevier BV

Date: 07-2019

DOI: 10.1016/J.IJGFS.2019.100148

Dietary balance during pregnancy is associated with fetal adiposity and fat distribution

Publisher: Elsevier BV

Date: 11-2012

DOI: 10.3945/AJCN.111.033241

Abstract: The prenatal environment can induce permanent changes in offspring phenotype. Thinness at birth is associated with adult risk of cardiometabolic disease. The objective was to investigate the association between maternal nutrition during pregnancy and intrauterine development of fetal body composition. We used prospective data from 179 Australian women with singleton pregnancies from the Women and Their Children's Health Study. A validated food-frequency questionnaire was used at 18-24 wk and 36-40 wk of gestation to quantify maternal diet during the previous 3 mo of pregnancy. Fetal body-composition measurements were ascertained from abdominal and midthigh sites by ultrasound performed at 19, 25, 30, and 36 wk. The subcutaneous fat area at each site was calculated by subtracting the lean/visceral area from the total area. In linear mixed-model regressions, maternal intakes of protein (b = -0.13 P = 0.04) and starch (b = 0.10 P = 0.02) and the protein:carbohydrate ratio (b = -3.61 P = 0.02) were associated with the percentage of abdominal fat, whereas SFA (b = 0.27 P = 0.04) and PUFA (b = -0.48 P = 0.03) were associated with the percentage of midthigh fat. Response surfaces for fetal adiposity were maximized at different macronutrient intakes. Abdominal fat was highest with low protein intakes ( 40% of energy), and low carbohydrate (<40% of energy) intakes. Fetal body composition may be modifiable via nutritional intervention in the mother and thus may play an important role in influencing the offspring's risk of future disease.

Modelling nutritional interactions: from individuals to communities.

Publisher: Elsevier BV

Date: 2010

DOI: 10.1016/J.TREE.2009.06.012

Abstract: Nutrient acquisition is a major context for ecological interactions among species but ecologists and nutritionists have developed theory in isolation from each other. Developments in agent-based modelling, state-space modelling of nutrition and multi-scale modelling of landscape ecology provide the components for a new synthesis in nutritional ecology linking the nutritional biology of in idual organisms to population- and community-level processes across multiple scales within an evolutionary context. We review the core elements for such a synthesis and set out the principles for a generic modelling framework that could be used to test specific ecological hypotheses.

CHANGES DURING THE FIFTH INSTAR OF LOCUSTA MIGRATORIA IN THE RATE OF CROP EMPTYING AND THEIR RELATIONSHIP TO FEEDING AND FOOD UTILISATION

Publisher: Wiley

Date: 05-1983

DOI: 10.1111/J.1570-7458.1983.TB03263.X

Nutrient-specific compensation following diapause in a predator: implications for intraguild predation

Publisher: Wiley

Date: 10-2007

DOI: 10.1890/07-0012.1

Abstract: In recent years it has become clear that intraguild predation (where predators feed on other predators) has important consequences for food webs, and yet very little is known about its nutritional or functional bases. In the most detailed study of the nutritional basis of foraging by a predator to date, we used geometrical analysis to test the ability of the generalist invertebrate predatory beetle, Agonum dorsale (Carabidae), to forage selectively for lipid and protein over a 10-day period following emergence from winter diapause, and we measured associated changes in body lipid and nitrogen content. Over the first 48 hours, beetles that were offered two nutritionally imbalanced but complementary foods self-selected a diet high in lipids, and thereafter the proportion of protein in the selected diet increased. Beetles confined to a single food with excess lipid (higher lipid:protein ratio than the self-selected diet) regulated intake to meet lipid requirements, while suffering a shortfall of protein. Those given diets with a lower lipid:protein ratio than the self-selected diet showed a progressive tendency across the 10-day experiment to over-ingest protein, thereby reducing the lipid deficit in their diet. Body composition changed markedly during the experiment, with the lipid content of the self-selecting insects increasing over the first 48 hours from 14% to 46% by dry mass, and thereafter remaining stable. We discuss some implications of our results for the understanding of intraguild predation.

Perspective: Tricks of the trade

Publisher: Springer Science and Business Media LLC

Date: 16-04-2014

DOI: 10.1038/508S66A

Arthropod food webs become increasingly lipid-limited at higher trophic levels

Publisher: Wiley

Date: 23-05-2013

DOI: 10.1111/ELE.12116

Abstract: Understanding why food chains are relatively short in length has been an area of research and debate for decades. We tested if progressive changes in the nutritional content of arthropods with trophic position limit the availability of a key nutrient, lipid, for carnivores. Arthropods at higher trophic levels had progressively less lipid and more protein in their bodies compared with arthropods at lower trophic levels. The nutrients present in arthropod bodies were directly related to the nutrients that predators extracted when feeding on those arthropods. As a consequence, nutrient assimilation shifted from lipid-biased to protein-biased as arthropods ascended trophic levels from herbivores to secondary carnivores. Successive changes in the nutritional consequences of predation may ultimately set an upper limit on the number of trophic levels in arthropod communities. Further work is needed to examine the influence of lipid and other nutrients on food web traits in a range of ecosystems.

Geometric framework reveals that a moderate protein, high carbohydrate intake is optimal for severe burn injury in mice

Publisher: Cambridge University Press (CUP)

Date: 27-01-2020

DOI: 10.1017/S0007114520000276

Abstract: Nutritional therapy is a cornerstone of burns management. The optimal macronutrient intake for wound healing after burn injury has not been identified, although high-energy, high-protein diets are favoured. The present study aimed to identify the optimal macronutrient intake for burn wound healing. The geometric framework (GF) was used to analyse wound healing after a 10 % total body surface area contact burn in mice ad libitum fed one of the eleven high-energy diets, varying in macronutrient composition with protein (P5−60 %), carbohydrate (C20−75 %) and fat (F20−75 %). In the GF study, the optimal ratio for wound healing was identified as a moderate-protein, high-carbohydrate diet with a protein:carbohydrate:fat (P:C:F) ratio of 1:4:2. High carbohydrate intake was associated with lower mortality, improved body weight and a beneficial pattern of body fat reserves. Protein intake was essential to prevent weight loss and mortality, but a protein intake target of about 7 kJ/d (about 15 % of energy intake) was identified, above which no further benefit was gained. High protein intake was associated with delayed wound healing and increased liver and spleen weight. As the GF study demonstrated that an initial very high protein intake prevented mortality, a very high-protein, moderate-carbohydrate diet (P40:C42:F18) was specifically designed. The dynamic diet study was also designed to combine and validate the benefits of an initial very high protein intake for mortality, and subsequent moderate protein, high carbohydrate intake for optimal wound healing. The dynamic feeding experiment showed switching from an initial very high-protein diet to the optimal moderate-protein, high-carbohydrate diet accelerated wound healing whilst preventing mortality and liver enlargement.

Branched chain amino acids, aging and age-related health

Publisher: Elsevier BV

Date: 12-2020

DOI: 10.1016/J.ARR.2020.101198

Macronutrient (im)balance drives energy intake in an obesogenic food environment: An ecological analysis

Publisher: Wiley

Date: 11-2022

DOI: 10.1002/OBY.23578

Abstract: The protein leverage hypothesis (PLH) postulates that strong regulation of protein intake drives energy overconsumption and obesity when human diets are diluted by fat and carbohydrates. The two predictions of the PLH are that humans (i) regulate intake to maintain protein within a narrow range and that (ii) energy intake is an inverse function of percentage energy from protein because absolute protein intake is maintained within narrow limits. Multidimensional nutritional geometry was used to test the predictions of the PLH using dietary data from the Australian National Nutrition and Physical Activity Survey. Both predictions of the PLH were confirmed in a population setting: the mean protein intake was 18.4%, and energy intake decreased with increasing energy from protein (L = −0.18, p 0.0001). It was demonstrated that highly processed discretionary foods are a significant diluent of protein and associated with increased energy but not increased protein intake. These results support an integrated ecological and mechanistic explanation for obesity, in which low‐protein highly processed foods lead to higher energy intake because of the biological response to macronutrient imbalance driven by a dominant appetite for protein. This study supports a central role for protein in the obesity epidemic, with significant implications for global health.

Geometric analysis of macronutrient selection in breeds of the domestic dog, Canis lupus familiaris

Publisher: Oxford University Press (OUP)

Date: 17-12-2013

DOI: 10.1093/BEHECO/ARS168

Nutritional balance of essential amino acids and carbohydrates of the adult worker honeybee depends on age

Publisher: Springer Science and Business Media LLC

Date: 13-03-2014

DOI: 10.1007/S00726-014-1706-2

The Evolution of Research on Ageing and Nutrition

Publisher: Oxford University Press (OUP)

Date: 10-09-2014

DOI: 10.1093/GERONA/GLT130

Modelling nutrition across organizational levels: from individuals to superorganisms

Publisher: Elsevier BV

Date: 10-2014

DOI: 10.1016/J.JINSPHYS.2014.03.004

Abstract: The Geometric Framework for nutrition has been increasingly used to describe how in idual animals regulate their intake of multiple nutrients to maintain target physiological states maximizing growth and reproduction. However, only a few studies have considered the potential influences of the social context in which these nutritional decisions are made. Social insects, for instance, have evolved extreme levels of nutritional interdependence in which food collection, processing, storage and disposal are performed by different in iduals with different nutritional needs. These social interactions considerably complicate nutrition and raise the question of how nutrient regulation is achieved at multiple organizational levels, by in iduals and groups. Here, we explore the connections between in idual- and collective-level nutrition by developing a modelling framework integrating concepts of nutritional geometry into in idual-based models. Using this approach, we investigate how simple nutritional interactions between in iduals can mediate a range of emergent collective-level phenomena in social arthropods (insects and spiders) and provide ex les of novel and empirically testable predictions. We discuss how our approach could be expanded to a wider range of species and social systems.

Metabolic consequences of feeding and fasting on nutritionally different diets in the wolf spider Pardosa prativaga

Publisher: Elsevier BV

Date: 09-2010

DOI: 10.1016/J.JINSPHYS.2010.03.001

Abstract: We investigated whether spiders fed lipid-rich rather than protein-rich prey elevate metabolism to avoid carrying excessive lipid deposits, or whether they store ingested lipids as a buffer against possible future starvation. We fed wolf spiders (Pardosa prativaga) prey of different lipid:protein compositions and measured the metabolic rate of spiders using closed respirometry during feeding and fasting. After a 16-day feeding period, spider lipid:protein composition was significantly affected by the lipid:protein composition of their prey. Feeding caused a large and fast increase in metabolism. The cost of feeding and digestion was estimated to average 21% of the ingested energy irrespective of diet. We found no difference in basal metabolic rate between dietary treatments. During starvation V ₀₂ and V(CO)₂decreased gradually, and the larger lipid stores in spiders fed lipid-rich prey appeared to extend survival of these spiders under starvation compared to spiders fed protein-rich prey. The results show that these spiders do not adjust metabolism in order to maintain a constant body composition when prey nutrient composition varies. Instead, lipids are stored efficiently and help to prepare the spiders for the long periods of food deprivation that may occur as a consequence of their opportunistic feeding strategy.

Challenges to assessing connectivity between massive populations of the Australian plague locust

Publisher: The Royal Society

Date: 09-03-2011

DOI: 10.1098/RSPB.2010.2605

Abstract: Linking demographic and genetic dispersal measures is of fundamental importance for movement ecology and evolution. However, such integration can be difficult, particularly for highly fecund species that are often the target of management decisions guided by an understanding of population movement. Here, we present an ex le of how the influence of large population sizes can preclude genetic approaches from assessing demographic population structuring, even at a continental scale. The Australian plague locust, Chortoicetes terminifera , is a significant pest, with populations on the eastern and western sides of Australia having been monitored and managed independently to date. We used microsatellites to assess genetic variation in 12 C. terminifera population s les separated by up to 3000 km. Traditional summary statistics indicated high levels of genetic ersity and a surprising lack of population structure across the entire range. An approximate Bayesian computation treatment indicated that levels of genetic ersity in C. terminifera corresponded to effective population sizes conservatively composed of tens of thousands to several million in iduals. We used these estimates and computer simulations to estimate the minimum rate of dispersal, m , that could account for the observed range-wide genetic homogeneity. The rate of dispersal between both sides of the Australian continent could be several orders of magnitude lower than that typically considered as required for the demographic connectivity of populations.

Parsing the life-shortening effects of dietary protein: effects of individual amino acids

Publisher: The Royal Society

Date: 11-01-2017

DOI: 10.1098/RSPB.2016.2052

Abstract: High-protein diets shorten lifespan in many organisms. Is it because protein digestion is energetically costly or because the final products (the amino acids) are harmful? To answer this question while circumventing the life-history trade-off between reproduction and longevity, we fed sterile ant workers on diets based on whole proteins or free amino acids. We found that (i) free amino acids shortened lifespan even more than proteins (ii) the higher the amino acid-to-carbohydrate ratio, the shorter ants lived and the lower their lipid reserves (iii) for the same amino acid-to-carbohydrate ratio, ants eating free amino acids had more lipid reserves than those eating whole proteins and (iv) on whole protein diets, ants seem to regulate food intake by prioritizing sugar, while on free amino acid diets, they seem to prioritize amino acids. To test the effect of the amino acid profile, we tested diets containing proportions of each amino acid that matched the ant's exome surprisingly, longevity was unaffected by this change. We further tested diets with all amino acids under-represented except one, finding that methionine, serine, threonine and phenylalanine are especially harmful. All together, our results show certain amino acids are key elements behind the high-protein diet reduction in lifespan.

Sex‐specific metabolic responses to 6 hours of fasting during the active phase in young mice

Publisher: Wiley

Date: 13-04-2020

DOI: 10.1113/JP278806

Dynamics of macronutrient self‐medication and illness‐induced anorexia in virally infected insects

Publisher: Wiley

Date: 02-09-2013

DOI: 10.1111/1365-2656.12127

Nutrient-specific compensatory feeding in a mammalian carnivore, the mink, Neovison vison

Publisher: Cambridge University Press (CUP)

Date: 20-08-2014

DOI: 10.1017/S0007114514001664

Abstract: Balancing of macronutrient intake has only recently been demonstrated in predators. In particular, the ability to regulate carbohydrate intake is little studied in obligate carnivores, as carbohydrate is present at very low concentrations in prey animal tissue. In the present study, we determined whether American mink ( Neovison vison ) would compensate for dietary nutritional imbalances by foraging for complementary macronutrients (protein, lipid and carbohydrate) when subsequently given a dietary choice. We used three food pairings, within which two macronutrients differed relative to each other (high v. low concentration), while the third was kept at a constant level. The mink were first restricted to a single nutritionally imbalanced food for 7 d and then given a free choice to feed from the same food or a nutritionally complementary food for three consecutive days. When restricted to nutritionally imbalanced foods, the mink were willing to overingest protein only to a certain level (‘ceiling’). When subsequently given a choice, the mink compensated for the period of nutritional imbalance by selecting the nutritionally complementary food in the food choice pairing. Notably, this rebalancing occurred for all the three macronutrients, including carbohydrate, which is particularly interesting as carbohydrate is not a major macronutrient for obligate carnivores in nature. However, there was also a ceiling to carbohydrate intake, as has been demonstrated previously in domestic cats. The results of the present study show that mink regulate their intake of all the three macronutrients within limits imposed by ceilings on protein and carbohydrate intake and that they will compensate for a period of nutritional imbalance by subsequently selecting nutritionally complementary foods.

Aging, lifestyle and dementia

Publisher: Elsevier BV

Date: 10-2019

DOI: 10.1016/J.NBD.2019.104481

Abstract: Aging is the greatest risk factor for most diseases including cancer, cardiovascular disorders, and neurodegenerative disease. There is emerging evidence that interventions that improve metabolic health with aging may also be effective for brain health. The most robust interventions are non-pharmacological and include limiting calorie or protein intake, increasing aerobic exercise, or environmental enrichment. In humans, dietary patterns including the Mediterranean, Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) and Okinawan diets are associated with improved age-related health and may reduce neurodegenerative disease including dementia. Rapamycin, metformin and resveratrol act on nutrient sensing pathways that improve cardiometabolic health and decrease the risk for age-associated disease. There is some evidence that they may reduce the risk for dementia in rodents. There is a growing recognition that improving metabolic function may be an effective way to optimize brain health during aging.

Kidney disease risk factors do not explain impacts of low dietary protein on kidney function and structure

Publisher: Elsevier BV

Date: 11-2021

DOI: 10.1016/J.ISCI.2021.103308

Calcium-Sensing Receptors Mediate Amino Acid Signals From the Liver to Islet Alpha Cells

Publisher: The Endocrine Society

Date: 17-03-2023

DOI: 10.1210/CLINEM/DGAD157

Male reproductive traits are differentially affected by dietary macronutrient balance but unrelated to adiposity

Publisher: Springer Science and Business Media LLC

Date: 04-05-2023

DOI: 10.1038/S41467-023-38314-X

Abstract: Dietary factors influence male reproductive function in both experimental and epidemiological studies. However, there are currently no specific dietary guidelines for male preconception health. Here, we use the Nutritional Geometry framework to examine the effects of dietary macronutrient balance on reproductive traits in C57BL/6 J male mice. Dietary effects are observed in a range of morphological, testicular and spermatozoa traits, although the relative influence of protein, fat, carbohydrate, and their interactions differ depending on the trait being examined. Interestingly, dietary fat has a positive influence on sperm motility and antioxidant capacity, differing to typical high fat diet studies where calorie content is not controlled for. Moreover, body adiposity is not significantly correlated with any of the reproductive traits measured in this study. These results demonstrate the importance of macronutrient balance and calorie intake on reproductive function and support the need to develop specific, targeted, preconception dietary guidelines for males.

Using field data to test locust migratory band collective movement models

Publisher: The Royal Society

Date: 08-2012

DOI: 10.1098/RSFS.2012.0024

Abstract: Wingless locust nymphs can form massive migratory groups known as bands, whose coordinated movement results from local interactions. We analysed the spatial distribution of locusts within naturally occurring bands and compared them with computer simulations to infer which interaction rules are used by in iduals. We found that the empirical radial distribution of neighbours around a focal in idual was isotropic, indicating a tendency for locusts to interact with neighbours all around them, rather than a bias towards pursuing in iduals ahead or escaping from the ones following behind. By using maps of neighbour densities and pair correlation functions, we found evidence for a short-range repulsion force, balanced by a clustering force, presumably alignment and/or attraction, at a distance of around 3 cm. These results were similar to those observed when using a ‘zonal’ self-propelled particles model where repulsion/alignment/attraction forces are delimited by concentric circular zones of set radii. However, the profiles obtained either by using different combinations of forces, limiting the number of neighbours involved in interactions, or by varying the range of some zones, all appeared to produce similar results, thereby limiting the ability to more precisely determine the rules underlying locust interactions.

Regulation of macronutrient intake in termites: A dietary self-selection experiment

Publisher: Elsevier BV

Date: 2020

DOI: 10.1016/J.JINSPHYS.2019.103983

Abstract: Many animals have been shown to select among nutritionally complementary foods to reach a specific balance of nutrients that optimizes key life history traits. Nutritional ecology theory, however, predicts that an animal with a diet that is very stable in its composition, and with nutritional requirements that do not vary in their balance through time, would not need to display such mechanisms of regulation. Here we use the Australian termite Nasutitermes exitiosus as a model to test this prediction for the first time. We used the nutritional geometric framework to investigate the regulation of carbohydrate and protein, as well as the effects on foraging behaviour of protein type and group caste composition and size. Our results support the prediction of nutritional ecology, as termites failed to actively defend a well-defined macronutrient ratio. Termites maintained food collection relatively constant across protein type and group composition, and only appear to vary their collection by avoiding diets too rich in protein.

Optimal foraging for specific nutrients in predatory beetles

Publisher: The Royal Society

Date: 11-01-2012

DOI: 10.1098/RSPB.2011.2410

Abstract: Evolutionary theory predicts that animals should forage to maximize their fitness, which in predators is traditionally assumed equivalent to maximizing energy intake rather than balancing the intake of specific nutrients. We restricted female predatory ground beetles ( Anchomenus dorsalis ) to one of a range of diets varying in lipid and protein content, and showed that total egg production peaked at a target intake of both nutrients. Other beetles given a choice to feed from two diets differing only in protein and lipid composition selectively ingested nutrient combinations at this target intake. When restricted to nutritionally imbalanced diets, beetles balanced the over- and under-ingestion of lipid and protein around a nutrient composition that maximized egg production under those constrained circumstances. Selective foraging for specific nutrients in this predator thus maximizes its reproductive performance. Our findings have implications for predator foraging behaviour and in the structuring of ecological communities.

Recent advances in the integrative nutrition of arthropods

Publisher: Annual Reviews

Date: 07-01-2015

DOI: 10.1146/ANNUREV-ENTO-010814-020917

Abstract: In this review we highlight recent advances in four areas in which nutrition shapes the relationships between organisms: between plants and herbivores, between hosts and their microbiota, between in iduals within groups and societies, and between species within food webs. We demonstrate that taking an explicitly multidimensional view of nutrition and employing the logic of the geometric framework for nutrition provide novel insights and offer a means of integration across different levels of organization, from in iduals to ecosystems.

Evolving migration

Publisher: Proceedings of the National Academy of Sciences

Date: 15-09-2010

DOI: 10.1073/PNAS.1011693107

Sardine cycles, krill declines, and locust plagues: Revisiting 'wasp-waist' food webs

Publisher: Elsevier BV

Date: 06-2014

DOI: 10.1016/J.TREE.2014.03.011

Abstract: 'Wasp-waist' systems are dominated by a mid trophic-level species that is thought to exert top-down control on its food and bottom-up control on its predators. Sardines, anchovy, and Antarctic krill are suggested ex les, and here we use locusts to explore whether the wasp-waist concept also applies on land. These ex les also display the traits of mobile aggregations and dietary ersity, which help to reduce the foraging footprint from their large, localised biomasses. This suggests that top-down control on their food operates at local aggregation scales and not at wider scales suggested by the original definition of wasp-waist. With this modification, the wasp-waist framework can cross-fertilise marine and terrestrial approaches, revealing how seemingly disparate but economically important systems operate.

Towards a new developmental synthesis: adaptive developmental plasticity and human disease

Publisher: Elsevier BV

Date: 05-2009

DOI: 10.1016/S0140-6736(09)60234-8

Serotonin Mediates Behavioral Gregarization Underlying Swarm Formation in Desert Locusts

Publisher: American Association for the Advancement of Science (AAAS)

Date: 30-01-2009

DOI: 10.1126/SCIENCE.1165939

Abstract: Desert locusts, Schistocerca gregaria , show extreme phenotypic plasticity, transforming between a little-seen solitarious phase and the notorious swarming gregarious phase depending on population density. An essential tipping point in the process of swarm formation is the initial switch from strong mutual aversion in solitarious locusts to coherent group formation and greater activity in gregarious locusts. We show here that serotonin, an evolutionarily conserved mediator of neuronal plasticity, is responsible for this behavioral transformation, being both necessary if behavioral gregarization is to occur and sufficient to induce it. Our data demonstrate a neurochemical mechanism linking interactions between in iduals to large-scale changes in population structure and the onset of mass migration.

Macronutrients modulate resistance to infection and immunity in Drosophila

Publisher: Cold Spring Harbor Laboratory

Date: 17-12-2018

DOI: 10.1101/498493

Abstract: Immunity and nutrition are two essential modulators of in idual fitness However, while the implications of immune function and nutrition on an in idual s lifespan and reproduction are known, the interplay between feeding behaviour, infection, and immune function, remains poorly understood. In this study, we used the fruit fly, Drosophila melanogaster, to investigate how infection through septic injury modulates nutritional intake, and how macronutrient balance affects survival to infection by the pathogenic Gram-positive bacterium Micrococcus luteus. Our results show that infected flies maintain carbohydrate intake, but reduce protein intake, thereby shifting from a protein-to-carbohydrate (P:C) ratio of ~1:4 to ~1:10 relative to non-infected and sham-infected flies. Strikingly, we found that the proportion of flies dying after M. luteus infection was significantly lower when flies were fed a low-P high-C diet, revealing that flies shift their macronutrient intake as means of nutritional self-medication against bacterial infection. This is likely due to the effects of macronutrient balance on the regulation of the constitutive expression of innate immune genes, as a low-P high-C diet was linked to an up-regulation in the expression of key antimicrobial peptides. Together, our results reveal the intricate relationship between macronutrient intake and resistance to infection, and integrate the molecular cross-talk between metabolic and immune pathways into the framework of nutritional immunology.

Body condition constrains immune function in field populations of female Australian plague locust Chortoicetes terminifera

Publisher: Wiley

Date: 27-04-2015

DOI: 10.1111/PIM.12179

Evolving resistance to obesity in an insect

Publisher: Proceedings of the National Academy of Sciences

Date: 19-09-2006

DOI: 10.1073/PNAS.0605225103

Abstract: Failure to adapt to a changing nutritional environment comes at a cost, as evidenced by the modern human obesity crisis. Consumption of energy-rich diets can lead to obesity and is associated with deleterious consequences not only in humans but also in many other animals, including insects. The question thus arises whether animals restricted over multiple generations to high-energy diets can evolve mechanisms to limit the deposition of adverse levels of body fat. We show that Plutella xylostella caterpillars reared for multiple generations on carbohydrate-rich foods (either a chemically defined artificial diet or a high-starch Arabidopsis mutant) progressively developed the ability to eat excess carbohydrate without laying it down as fat, providing strong evidence that excess fat storage has a fitness cost. In contrast, caterpillars reared in carbohydrate-scarce environments (a chemically defined artificial diet or a low-starch Arabidopsis mutant) had a greater propensity to store ingested carbohydrate as fat. Additionally, insects reared on the low-starch Arabidopsis mutant evolved a preference for laying their eggs on this plant, whereas those selected on the high-starch Arabidopsis mutant showed no preference. Our results provide an experimental ex le of metabolic adaptation in the face of changes in the nutritional environment and suggest that changes in plant macronutrient profiles may promote host-associated population ergence.

A journey towards an integrated understanding of behavioural phase change in locusts

Publisher: Elsevier BV

Date: 04-2022

DOI: 10.1016/J.JINSPHYS.2022.104370

Abstract: Behavioural phase change initiates and functionally couples the suite of traits that comprise density-dependent polyphenism in locusts. Here I provide a semi-expurgated account of my 25-year research journey studying behavioural phase transition in the desert locust. The journey spans continents, involves a cast of extraordinary colleagues, and travels across levels of biological organisation from deep within the nervous system of in idual locusts to mass migration and the evolution and population dynamics of swarming.

A correlation between macronutrient balancing and insect host-plant range: Evidence from the specialist caterpillar Spodoptera exempta (Walker)

Publisher: Elsevier BV

Date: 12-2003

DOI: 10.1016/J.JINSPHYS.2003.08.013

Abstract: In an earlier study, we showed that the ingestive responses of the generalist caterpillar Spodoptera littoralis to foods imbalanced in their protein:carbohydrate content is similar to generalist locusts, but differs from that of specialist-feeding locusts. Here we further pursued the comparison by repeating the experiments using a closely related specialist caterpillar, Spodoptera exempta. First, caterpillars were allowed to self-compose a diet of preferred protein:carbohydrate balance by mixing between nutritionally complementary foods. Then, they were confined to one of five imbalanced foods, in which we measured the trade-off between over- and under-ingesting the two nutrients. On complementary foods, the caterpillars actively regulated their protein and carbohydrate intake. In the no-choice experiment, those fed excess-protein foods ingested small surpluses of protein compared with generalist feeders, thus showing a pattern of nutrient balancing similar to that observed in specialist locusts. Utilisation data indicated that ingested excesses and deficits were to some extent offset by differential utilisation. Evidence also showed that post-ingestive responses of the specialist S. exempta were less flexible than those observed in the generalist S. littoralis, a pattern which is again in accordance with comparisons of acridids differing in their host-plant range.

Macronutrients mediate the functional relationship between Drosophila and Wolbachia

Publisher: The Royal Society

Date: 07-02-2015

DOI: 10.1098/RSPB.2014.2029

Abstract: Wolbachia are maternally inherited bacterial endosymbionts that naturally infect a erse array of arthropods. They are primarily known for their manipulation of host reproductive biology, and recently, infections with Wolbachia have been proposed as a new strategy for controlling insect vectors and subsequent human-transmissible diseases. Yet, Wolbachia abundance has been shown to vary greatly between in iduals and the magnitude of the effects of infection on host life-history traits and protection against infection is correlated to within-host Wolbachia abundance. It is therefore essential to better understand the factors that modulate Wolbachia abundance and effects on host fitness. Nutrition is known to be one of the most important mediators of host–symbiont interactions. Here, we used nutritional geometry to quantify the role of macronutrients on insect– Wolbachia relationships in Drosophila melanogaster . Our results show fundamental interactions between diet composition, host diet selection, Wolbachia abundance and effects on host lifespan and fecundity. The results and methods described here open a new avenue in the study of insect– Wolbachia relationships and are of general interest to numerous research disciplines, ranging from nutrition and life-history theory to public health.

Lower Protein-to-Carbohydrate Ratio in Maternal Diet is Associated with Higher Childhood Systolic Blood Pressure up to Age Four Years

Publisher: MDPI AG

Date: 24-04-2015

DOI: 10.3390/NU7053078

CHANGES IN THE EFFICIENCY OF UTILISATION OF FOOD THROUGHOUT THE FIFTH‐INSTAR NYMPHS OF LOCUSTA MIGRATORIA

Publisher: Wiley

Date: 03-1982

DOI: 10.1111/J.1570-7458.1982.TB03144.X

Abstract: The amounts eaten and the efficiency of utilisation of food were studied in detail for 5th‐instar nymphs of Locusta migratoria reared under a 12: 12 LD photoregime at 30°. Changes were found between the light and dark periods, and throughout the instar, in the amount of food eaten, dry weight growth efficiency and % water retention. Variations in dry weight growth efficiency were strongly correlated with changes in the efficiency of absorption of proteins. The absorption of dietary lipids followed a similar trend to that for proteins, while soluble carbohydrates were absorbed at a higher and more constant rate. Variations in the % of water retained from the food were reflected in changes in haemolymph volume and total body water content, while overall growth processes reflected the patterns of nutrient absorption. Males and females showed many similarities in the patterns of feeding, food utilisation and overall growth but greater amounts of nutrients were consumed by females which are generally larger than males. The author thanks Drs. R. F. Chapman, E. A. Bernays, W. M. Blaney and F. Slansky Jr. for help and criticism. Thanks also to other colleagues at the Centre for Overseas Pest Research for assistance and to Mr. A. G. Scott at Queen Mary College for some of the microkjeldahl analyses. Carried out under a grant from the University of Queensland. Évolution de l'efficacité de l'utilisation des aliments au cours du cinquième stade larvaire de Locusta migratoria Les quantités consummées et l'efficacité de l'utilisation des aliments ont été étudiées en détail pendant le cinquième stade larvaire de L. migratoria élevées à 30° sous photopériode 12/12. Les quantités d'aliment consommées, l'efficacité de la croissance en poids sec et le taux de retention d'eau ont tous été plus faibles pendant la plupart des scotofractions. Ces paramètres varient aussi au cours du cinquième avec un maximum de consommation à la moitié du stade, et des maxima en efficacité de croissance en poids sec et en rétention d'eau le jour de la mue du cinquième stade et 4 jours après. Les variations de l'efficacité de la croissance en poids sec sont fortement liées à l'efficacité de l'absorption des protéines. L'absorption des lipides alimentaires présente une tendance similaire à celle des protéines, tandis que les carbohydrates solubles sont absorbés à un taux plus élevé et plus constant. Les variations dans le taux d'eau retenue à partir des aliments se sont manifestées dans les variations de volume de l'hémolymphe et la teneur totale en eau du corps, tandis que les processus globaux de la croissance tels que la variation en lipides, en protides et en carbohydrates du corps ont refleté les caractéristiques de l'absorption d'aliment. Les males et les femelles ont présenté de nombreuses similarités dans les modes d'alimentation, d'utilisation de la nourriture et de croissance globale et les différences paraissaient liées pour beaucoup au fait que les femelles sont généralement plus grosses que les mâles.

Substantial changes in central nervous system neurotransmitters and neuromodulators accompany phase change in the locust

Publisher: The Company of Biologists

Date: 15-09-2004

DOI: 10.1242/JEB.01183

Abstract: Desert locusts (Schistocerca gregaria) can undergo a profound transformation between solitarious and gregarious forms, which involves widespread changes in behaviour, physiology and morphology. This phase change is triggered by the presence or absence of other locusts and occurs over a timescale ranging from hours, for some behaviours to change, to generations,for full morphological transformation. The neuro-hormonal mechanisms that drive and accompany phase change in either direction remain unknown. We have used high-performance liquid chromatography (HPLC) to compare amounts of 13 different potential neurotransmitters and/or neuromodulators in the central nervous systems of final instar locust nymphs undergoing phase transition and between long-term solitarious and gregarious adults. Long-term gregarious and solitarious locust nymphs differed in 11 of the 13 substances analysed: eight increased in both the brain and thoracic nerve cord (including glutamate,GABA, dopamine and serotonin), whereas three decreased (acetylcholine,tyramine and citrulline). Adult locusts of both extreme phases were similarly different. Isolating larval gregarious locusts led to rapid changes in seven chemicals equal to or even exceeding the differences seen between long-term solitarious and gregarious animals. Crowding larval solitarious locusts led to rapid changes in six chemicals towards gregarious values within the first 4 h(by which time gregarious behaviours are already being expressed), before returning to nearer long-term solitarious values 24 h later. Serotonin in the thoracic ganglia, however, did not follow this trend, but showed a ninefold increase after a 4 h period of crowding. After crowding solitarious nymphs for a whole larval stadium, the amounts of all chemicals, except octopamine, were similar to those of long-term gregarious locusts. Our data show that changes in levels of neuroactive substances are widespread in the central nervous system and reflect the time course of behavioural and physiological phase change.

90th Anniversary Commentary: Caloric Restriction Effects on Aging

Publisher: Elsevier BV

Date: 10-2018

DOI: 10.1093/JN/NXY146

Diet has independent effects on the pace and shape of aging in Drosophila melanogaster

Publisher: Springer Science and Business Media LLC

Date: 15-09-2017

DOI: 10.1007/S10522-017-9729-1

Changes in micronutrient intake and factors associated with this change among older Australian men: the Concord Health and Ageing in Men Project

Publisher: Cambridge University Press (CUP)

Date: 08-09-2021

DOI: 10.1017/S1368980020003249

Abstract: To examine changes in micronutrient intake over 3 years and identify any associations between socio-economic, health, lifestyle and meal-related factors and these changes in micronutrient intakes among older men. Prospective study. Dietary adequacy of in idual micronutrient was compared to the estimated average requirement of the nutrient reference values (NRV). Attainment of the NRV for twelve micronutrients was incorporated into a dichotomised variable ‘not meeting’ (meeting ≤ 6) or ‘meeting’ (meeting ≥ 7) and categorised into four categories to assess change in micronutrient intake over 3 years. The multinomial logistic regression analyses were conducted to model predictors of changes in micronutrient intake. Seven hundred and ninety-four men participated in a detailed diet history interview at the third wave (baseline nutrition) and 718 men participated at the fourth wave (3-year follow-up). The mean age was 81 years (range 75–99 years). Median intakes of the majority of micronutrients decreased significantly over a 3-year follow-up. Inadequacy of the NRV for thiamine, dietary folate, Zn, Mg, Ca and I were significantly increased at a 3-year follow-up than baseline nutrition. The incidence of inadequate micronutrient intake was 21 % and remained inadequate micronutrient intake was 16·4 % at 3-year follow-up. Changes in micronutrient intakes were significantly associated with participants born in the UK and Italy, low levels of physical activity, having ≥2 medical conditions and used meal services. Micronutrient intake decreases with age in older men. Our results suggest that strategies to improve some of the suboptimal micronutrient intakes might need to be developed and implemented for older men.

A randomized clinical trial to investigate the effect of dietary protein sources on periodontal health

Publisher: Wiley

Date: 24-01-2022

DOI: 10.1111/JCPE.13587

Abstract: The aim was to assess two macronutrient interventions in a 2 × 2 factorial dietary design to determine their effects on oral health. Participants (65–75 years old) with a body mass index between 20 and 35 kg/m 2 of a larger randomized control trial who consented to an oral health assessment were recruited. They had ad libitum access to one of four experimental diets (omnivorous higher fat or higher carbohydrate, semi‐vegetarian higher fat or higher carbohydrate) for 4 weeks. The periodontal examination included periodontal probing depth (PPD), clinical attachment level (CAL), and bleeding on probing. Oral plaque and gingival crevicular fluid (GCF) were collected before and after the intervention. Between baseline and follow up, the number of sites with a CAL mm (mean difference [MD] −5.11 ± 9.68, p = .039) increased and the GCF amount (MD −23.42 ± 39.42 Periotron Units [PU], p = .050) decreased for the semi‐vegetarian high‐fat diet. For the mean proportion of sites with PPD reduction of mm and CAL gain of mm, significant differences were calculated between the diets investigated. The clinical parameters were not associated with changes in the oral microbiota. The results of this study provided evidence that a semi‐vegetarian high‐fat diet provides benefits to clinical parameters of periodontal health. This study is registered in ClinicalTrials.gov (ACTRN12616001606471).

Insect herbivores can choose microclimates to achieve nutritional homeostasis

Publisher: The Company of Biologists

Date: 2013

DOI: 10.1242/JEB.078782

Abstract: The interaction between temperature and diet quality can affect the life-history of ectotherms. The rate and ratio at which protein and carbohydrate are obtained from food are an important aspect of diet quality, and insects have a well-developed capacity to adjust their feeding behaviour and postingestive physiology to regulate intake and allocation of these nutrients. If the supply of protein and carbohydrate varies with temperature (e.g. via effects on intake, digestion or metabolism), then herbivorous insects can use thermoregulatory behaviour to help achieve nutritional homeostasis. When fed the host grass Triticum aestivum, Locusta migratoria nymphs absorbed and allocated protein and carbohydrate to growth with the same efficiency at 38°C as at 32°C, however, at the higher temperature, they ingested more food. In contrast, when feeding on Themeda triandra, the nymphs absorbed carbohydrate with higher efficiency at 32°C and protein at 38°C. Using synthetic diets, we induced either a protein or a carbohydrate deficiency in experimental insects and showed that locusts placed in a thermal gradient following a meal of T. triandra selected 32°C when deprived of carbohydrate, and 38°C when protein-deficient. This capacity to use thermoregulatory behaviour to redress an imposed nutritional imbalance improved with experience of feeding on T. triandra. As predicted, locusts fed T. aestivum always chose higher temperatures, irrespective of nutritional state. Our results have consequences for understanding host plant choice by herbivores and interpreting the effects of changed environmental temperatures and microclimate on animal-plant interactions.

Protein-induced weight increase of the gastrointestinal tract of locusts improves net nutrient uptake via larger meals rather than more efficient nutrient absorption

Publisher: The Company of Biologists

Date: 2012

DOI: 10.1242/JEB.076489

Abstract: Increasing the tissue biomass and/or volume of the gastrointestinal tract (GIT) is commonly seen when animals feed on poor quality diets. This increase can simply permit larger meal sizes, but may also rebalance nutritionally imbalanced ingesta by allowing selective absorption of limiting nutrients. In an insect herbivore, the migratory locust, a synthetic diet with a high ratio of protein to carbohydrate was found to induce weight enhancement of the GIT. When normalized for sex and overall body size, increases to the mass of the foregut and midgut caeca resulted in higher absorption (20-30%) of both protein and carbohydrate when subsequently feeding on three chemically and structurally different grasses. Greater net absorption of macronutrients occurred because these locusts ate larger meals that transited at the same time and with the same digestive efficiency as locusts in which the GIT was not enlarged. Thus, plasticity of the GIT did not improve nutritional homeostasis, but increased the rate of nutrient uptake.

Macronutrient intakes and the lifespan-fecundity trade-off: a geometric framework agent-based model

Publisher: The Royal Society

Date: 02-2019

DOI: 10.1098/RSIF.2018.0733

Abstract: Lifespan and fecundity, the main components in evolutionary fitness, are both strongly affected by nutritional state. Geometric framework of nutrition (GFN) experiments has shown that lifespan and fecundity are separated in nutrient space leading to a functional trade-off between the two traits. Here we develop a spatially explicit agent-based model (ABM) using the GFN to explore how ecological factors may cause selection on macronutrient appetites to optimally balance these life-history traits. We show that increasing the risk of extrinsic mortality favours intake of a mixture of nutrients that is associated with maximal fecundity at the expense of reduced longevity and that this result is robust across spatial and nutritional environments. These model behaviours are consistent with what has been observed in studies that quantify changes in life history in response to environmental manipulations. Previous GFN-derived ABMs have treated fitness as a single value. This is the first such model to instead decompose fitness into its primary component traits, longevity and fecundity, allowing evolutionary fitness to be an emergent property of the two. Our model demonstrates that selection on macronutrient appetites may affect life-history trade-offs and makes predictions that can be directly tested in artificial selection experiments.

Towards a synthesis of frameworks in nutritional ecology: Interacting effects of protein, carbohydrate and phosphorus on field cricket fitness

Publisher: The Royal Society

Date: 07-10-2014

DOI: 10.1098/RSPB.2014.0539

Abstract: Phosphorus has been identified as an important determinant of nutrition-related biological variation. The macronutrients protein (P) and carbohydrates (C), both alone and interactively, are known to affect animal performance. No study, however, has investigated the importance of phosphorus relative to dietary protein or carbohydrates, or the interactive effects of phosphorus with these macronutrients, on fitness-related traits in animals. We used a nutritional geometry framework to address this question in adult field crickets ( Gryllus veletis ). Our results showed that lifespan, weight gain, acoustic mate signalling and egg production were maximized on diets with different P : C ratios, that phosphorus did not positively affect any of these fitness traits, and that males and females had different optimal macronutrient intake ratios for reproductive performance. When given a choice, crickets selected diets that maximized both lifespan and reproductive performance by preferentially eating diets with low P : C ratios, and females selected diets with a higher P : C ratio than males. Conversely, phosphorus intake was not regulated. Overall, our findings highlight the importance of disentangling the influences of different nutrients, and of quantifying both their in idual and interactive effects, on animal fitness traits, so as to gain a more integrative understanding of their nutritional ecology.

Caloric restriction and aging revisited: The need for a geometric analysis of the nutritional bases of aging

Publisher: Oxford University Press (OUP)

Date: 07-2007

DOI: 10.1093/GERONA/62.7.707

Abstract: One of the most important findings in the field of the biology of aging has been the demonstration that modest dietary restriction extends life span in a wide range of taxonomically disparate organisms. There is currently a debate as to whether longevity is prolonged because of caloric restriction or due to more specific nutrient effects. Recent advances in nutritional research, notably the development of state-space geometric models, the Geometric Framework (GF), offer new opportunities to disentangle the effects of calories and nutrients. We begin by introducing these models, then set out the four questions that must be addressed to establish the relationship between nutrition and aging and indicate how the GF might help in answering these. We next provide an exemplar experimental protocol and consider some practical challenges to implementing the GF. Our conclusion is that Drosophila provides the most suitable system for an initial study.

Polyphenism in Insects

Publisher: Elsevier BV

Date: 09-2011

DOI: 10.1016/J.CUB.2011.06.006

Abstract: Polyphenism is the phenomenon where two or more distinct phenotypes are produced by the same genotype. Ex les of polyphenism provide some of the most compelling systems for the study of epigenetics. Polyphenisms are a major reason for the success of the insects, allowing them to partition life history stages (with larvae dedicated to feeding and growth, and adults dedicated to reproduction and dispersal), to adopt different phenotypes that best suit predictable environmental changes (seasonal morphs), to cope with temporally heterogeneous environments (dispersal morphs), and to partition labour within social groups (the castes of eusocial insects). We survey the status of research on some of the best known ex les of insect polyphenism, in each case considering the environmental cues that trigger shifts in phenotype, the neurochemical and hormonal pathways that mediate the transformation, the molecular genetic and epigenetic mechanisms involved in initiating and maintaining the polyphenism, and the adaptive and life-history significance of the phenomenon. We conclude by highlighting some of the common features of these ex les and consider future avenues for research on polyphenism.

Sucrose and starch intake contribute to reduced alveolar bone height in a rodent model of naturally occurring periodontitis

Publisher: Public Library of Science (PLoS)

Date: 13-03-2019

DOI: 10.1371/JOURNAL.PONE.0212796

Osmolality as a Novel Mechanism Explaining Diet Effects on the Outcome of Infection with a Blood Parasite

Publisher: Elsevier BV

Date: 07-2020

DOI: 10.1016/J.CUB.2020.04.058

Match and mismatch: Conservation physiology, nutritional ecology and the timescales of biological adaptation

Publisher: The Royal Society

Date: 19-06-2012

DOI: 10.1098/RSTB.2012.0007

Abstract: Conservation physiology (CP) and nutritional ecology (NE) are both integrative sciences that share the fundamental aim of understanding the patterns, mechanisms and consequences of animal responses to changing environments. Here, we explore the high-level similarities and differences between CP and NE, identifying as central themes to both fields the multiple timescales over which animals adapt (and fail to adapt) to their environments, and the need for integrative models to study these processes. At one extreme are the short-term regulatory responses that modulate the state of animals in relation to the environment, which are variously considered under the concepts of homeostasis, homeorhesis, enantiostasis, heterostasis and allostasis. In the longer term are developmental responses, including phenotypic plasticity and transgenerational effects mediated by non-genomic influences such as parental physiology, epigenetic effects and cultural learning. Over a longer timescale still are the cumulative genetic changes that take place in Darwinian evolution. We present ex les showing how the adaptive responses of animals across these timescales have been represented in an integrative framework from NE, the geometric framework (GF) for nutrition, and close with an illustration of how GF can be applied to the central issue in CP, animal conservation.

A framework for uncovering the roles of calories and macronutrients in health and aging

Publisher: Elsevier

Date: 2018

DOI: 10.1016/B978-0-12-811353-0.00008-7

Testing the protein-leverage hypothesis using population surveillance data

Publisher: The Royal Society

Date: 09-2022

DOI: 10.1098/RSOS.220756

Abstract: It is hypothesized that humans exhibit ‘protein leverage’ (PL), whereby regulation of absolute protein intake results in the over-consumption of non-protein food on low percentage protein diets. Testing for PL using dietary surveillance data involves seeking evidence for a negative association between total energy intake and percentage energy from protein. However, it is unclear whether such an association might emerge without PL due to the structure of intake data (protein and non-protein intakes have different means and variances and covary). We derive a set of models that describe the association between the expected estimate of PL and the distributions of protein and non-protein intake. Models were validated via simulation. Patterns consistent with PL will not emerge simply because protein intake has a lower mean and/or variance than non-protein. Rather, evidence of PL is observed where protein has a lower index of dispersion (variance/mean) than non-protein intake. Reciprocally, the stronger PL is the lower the index of dispersion for protein intake becomes. Disentangling causality is ultimately beyond the power of observational data alone. However, we show that one can correct for confounders (e.g. age) in generating signals of PL, and describe independent measures that can anchor inferences around the role of PL.

Evidence for the protein leverage hypothesis in preschool children prone to obesity

Publisher: Elsevier BV

Date: 11-2023

DOI: 10.1016/J.CLNU.2023.09.025

The ratio of macronutrients, not caloric intake, dictates cardiometabolic health, aging, and longevity in ad libitum-fed mice

Publisher: Elsevier BV

Date: 03-2014

DOI: 10.1016/J.CMET.2014.02.009

Rapid behavioural gregarization in the desert locust, Schistocerca gregaria entails synchronous changes in both activity and attraction to conspecifics

Publisher: Elsevier BV

Date: 06-2014

DOI: 10.1016/J.JINSPHYS.2014.04.004

Protein and carbohydrate intakes alter gut microbial community structure in crickets: a Geometric Framework approach

Publisher: Oxford University Press (OUP)

Date: 04-07-2019

DOI: 10.1093/FEMSEC/FIZ106

Abstract: Proteins and carbohydrates have profound impacts on the ecology of gut microbiota, but disentangling the single and interactive effects of different dietary constituents is challenging. Here, we used a multidimensional approach, the Geometric Framework, to study the interactions between nutrition and bacterial abundances with respect to protein and carbohydrate intakes in field cricket, Teleogryllus oceanicus. Our study revealed that species richness decreased as crickets consumed more macronutrients, and species evenness peaked at high intake of protein-rich diets. Sex and protein:carbohydrate (P:C) ratios in diets were the primary factors influencing the gut bacterial community, but most of the microbial operational taxonomic units (OTUs) that were significantly different between males and females were present in low abundance. In contrast, protein intake had a greater influence than carbohydrate consumption on the relative abundances of the core bacterial taxa, as an increase in dietary protein availability could remove the growth constraint imposed by limited nitrogen. Taken together, the use of the Geometric Framework provides a deeper insight into how nutritional intakes influence the relative abundances of gut microbes, and could be a useful tool to integrate the study of gut microbiome and fitness traits in a host.

Defining the impact of dietary macronutrient balance on PCOS traits

Publisher: Springer Science and Business Media LLC

Date: 16-10-2020

DOI: 10.1038/S41467-020-19003-5

Abstract: Lifestyle, mainly dietary, interventions are first-line treatment for women with polycystic ovary syndrome (PCOS), but the optimal diet remains undefined. We combined a hyperandrogenized PCOS mouse model with a systematic macronutrient approach, to elucidate the impact of dietary macronutrients on the development of PCOS. We identify that an optimum dietary macronutrient balance of a low protein, medium carbohydrate and fat diet can ameliorate key PCOS reproductive traits. However, PCOS mice display a hindered ability for their metabolic system to respond to diet variations, and varying macronutrient balance did not have a beneficial effect on the development of metabolic PCOS traits. We reveal that PCOS traits in a hyperandrogenic PCOS mouse model are ameliorated selectively by diet, with reproductive traits displaying greater sensitivity than metabolic traits to dietary macronutrient balance. Hence, providing evidence to support the development of evidence-based dietary interventions as a promising strategy for the treatment of PCOS, especially reproductive traits.

A geometry of regulatory scaling

Publisher: University of Chicago Press

Date: 11-2008

DOI: 10.1086/591686

Abstract: Over recent years, data have accumulated for an ecologically and taxonomically erse range of animals showing that the mechanisms of feeding regulation prioritize a balanced gain of multiple nutrients. This emerging generality calls for an approach, equivalent to multidimensional morphometrics in the field of evolutionary morphology, in which regulatory systems are represented in more than one dimension. We use geometry to provide a quantitative metric of such regulatory phenotypes, which enables us to empirically address the evolutionarily interesting question of how the parameters of regulatory systems reflect performance outcomes. First, we develop a parameter-efficient geometry characterizing regulatory scaling strategies in two nutrient dimensions. We then take empirical data from several species (insects, birds, and mammals, including humans) in which in iduals were limited to one of a small number of diets varying in the balance of macronutrients, and we explore which metrics and scaling techniques best unite within a common descriptive framework their patterns of regulation. We next show how a similar approach might be applied in the context of equilibrium models of operant conditioning and briefly discuss the potential for integrating such an approach into evolutionary and ecological studies.

Diet modulates the relationship between immune gene expression and functional immune responses

Publisher: Elsevier BV

Date: 06-2019

DOI: 10.1016/J.IBMB.2019.04.009

Maternal dietary fatty acid composition and newborn epigenetic aging—a geometric framework approach

Publisher: Elsevier BV

Date: 2022

DOI: 10.1093/AJCN/NQAB318

Abstract: Maternal nutrition is associated with epigenetic and cardiometabolic risk factors in offspring. Research in humans has primarily focused on assessing the impact of in idual nutrients. We sought to assess the collective impact of maternal dietary MUFAs, PUFAs, and SFAs on epigenetic aging and cardiometabolic risk markers in healthy newborn infants using a geometric framework approach. Body fatness (n = 162), aortic intima-media thickness (aIMT n = 131), heart rate variability (n = 118), and epigenetic age acceleration (n = 124) were assessed in newborn infants. Maternal dietary intake was cross-sectionally assessed in the immediate postpartum period via a validated 80-item self-administered FFQ. Generalized additive models were used to explore interactive associations of nutrient intake, with results visualized as response surfaces. After adjustment for total energy intake, maternal age, gestational age, and sex there was a 3-way interactive association of MUFAs, PUFAs, and SFAs (P = 0.001) with newborn epigenetic aging. This suggests that the nature of each fat class association depends upon one another. Response surfaces revealed MUFAs were positively associated with newborn epigenetic age acceleration only at proportionately lower intakes of SFAs or PUFAs. We also demonstrate a potential beneficial association of omega-3 (n-3) PUFAs with newborn epigenetic age acceleration (P = 0.008). There was no significant association of fat class with newborn aIMT, heart rate variability, or body fatness. In this study, we demonstrated an association between maternal dietary fat class composition and epigenetic aging in newborns. Future research should consider other characteristics such as the source of maternal dietary fatty acids.

Thanatosis

Publisher: Elsevier BV

Date: 11-2014

DOI: 10.1016/J.CUB.2014.08.051

Abstract: In this quick guide, Rogers and Simpson provide an overview of thanatosis, the fascinating behaviour of feigning death, seen in animals ranging from insects to mammals.

Macronutrient contributions of insects to the diets of hunter-gatherers: A geometric analysis

Publisher: Elsevier BV

Date: 06-2014

DOI: 10.1016/J.JHEVOL.2014.02.007

Abstract: We present a geometric model for examining the macronutrient contributions of insects in the diets of pre-agricultural humans, and relate the findings to some contemporary societies that regularly eat insects. The model integrates published data on the macronutrient composition of insects and other foods in the diets of humans, recommended human macronutrient intakes, and estimated macronutrient intakes to examine the assumption that insects provided to pre-agricultural humans an invertebrate equivalent of vertebrate-derived meats, serving primarily as a source of protein. Our analysis suggests that insects vary more widely in their macronutrient content than is likely to be the case for most wild vertebrate meats, spanning a broad range of protein, fat and carbohydrate concentrations. Potentially, therefore, in terms of their proportional macronutrient composition, insects could serve as equivalents not only of wild meat, but of a range of other foods including some shellfish, nuts, pulses, vegetables and even fruits. Furthermore, humans might systematically manipulate the composition of edible insects to meet specific needs through pre-ingestive processing, such as cooking and selective removal of body parts. We present data suggesting that in modern societies for which protein is the more limiting macronutrient, pre-ingestive processing of edible insects might serve to concentrate protein. It is likely, however, that the dietary significance of insects was different for Paleolithic hunter-gatherers who were more limited in non-protein energy. Our conclusions are constrained by available data, but highlight the need for further studies, and suggest that our model provides an integrative framework for conceiving these studies.

Taxa-specific heat shock proteins are over-expressed with crowding in the Australian plague locust

Publisher: Elsevier BV

Date: 11-2011

DOI: 10.1016/J.JINSPHYS.2011.08.011

Abstract: Most heat shock proteins (Hsps) function as molecular chaperones that help organisms to cope with stress. Although the best empirical evidence is related to heat shock, there is evidence that Hsps and their encoding genes are involved in resistance to other ecologically relevant types of stresses such as those imposed by high population density. We quantified density-dependent gene expression of large (i.e. Hsp40, Hsc70 and Hsp90) and small (Hsp20.5, Hsp20.6 and Hsp20.7) heat shock genes in neural tissue of fifth-instar nymphs of the Australian plague locust, Chortoicetes terminifera, using reverse transcription-quantitative PCR. Locusts are of particular interest when studying the influence of stress induced by high population density since they show an extreme form of phenotypic plasticity changing from a cryptic solitarious phase to a swarming gregarious phase. Crowding led to a synchronous and sustained 2-3 fold increase in the expression of only two Hsp genes, Hsp20.5 and Hsp20.7, which do not BLAST with any known animal sequences and therefore are likely to be unique to members of the Orthoptera. This study opens a range of experiments to investigate the possibility of specific roles for these two small Hsps in the resistance to stressful conditions imposed by crowded environments and/or the expression of gregarious behavior as well as their evolutionary significance to locusts whose populations are regularly exposed to high density conditions in the field.

Prey nutrient composition has different effects on Pardosa wolf spiders with dissimilar life histories

Publisher: Springer Science and Business Media LLC

Date: 26-10-2011

DOI: 10.1007/S00442-010-1811-1

Abstract: The nutritional composition of prey is known to influence predator life histories, but how the life history strategies of predators affect their susceptibility to nutrient imbalance is less investigated. We used two wolf spider species with different life histories as model predators: Pardosa amentata, which have a fixed annual life cycle, and Pardosa prativaga, which reproduce later and can extend development across 2 years. We fed juvenile spiders of the two species ad libitum diets of one of six Drosophila melanogaster fly types varying in lipid:protein composition during three instars, from the start of the second instar until the fifth instar moult. We then tested for interactions between predator species and prey nutrient composition on several life history parameters. P. amentata completed the three instars faster and grew larger carapaces and heavier body masses than P. prativaga, but the two species responded differently to variation in prey lipid:protein ratio. Duration of the instars increased when feeding on protein-poor prey in P. amentata, but was unaffected by diet in P. prativaga. Likewise, the effect of diet on body composition was more pronounced in P. amentata than in P. prativaga. Prey nutrient composition thus affected the two species differently. During macronutrient imbalance P. amentata appear to prioritize high growth rates while experiencing highly variable body compositions, whereas P. prativaga maintain more constant body compositions and have slower growth. These can be seen as different consequences of a fixed annual and a plastic annual-biennial life cycle.

Meta-analysis links dietary branched-chain amino acids to metabolic health in rodents

Publisher: Springer Science and Business Media LLC

Date: 14-01-2022

DOI: 10.1186/S12915-021-01201-2

Abstract: The role of dietary branched chain amino acids (BCAAs) and their effect on metabolic health is complex. How dietary BCAA levels and their interaction with background nutrition affect health is unclear. Here, we used meta-analysis and meta-regression, together with the nutritional modelling, to analyse the results of rodent studies that increased the level of dietary BCAAs and measured circulating levels, outcomes related to metabolic health, body mass and food intake. Across all studies, increasing dietary BCAAs resulted in increased levels of circulating BCAAs. These effects, however, were heavily moderated by background dietary levels whereby on high BCAA diets, further increases were not reflected in the blood. Impaired glucose tolerance was associated with elevated dietary BCAAs, with the greatest effect occurring with a simultaneous increase in total protein intake. Effects of dietary BCAAs on plasma glucose, insulin, or HOMA emerged only when dietary macronutrient background was considered. We found that elevated dietary BCAAs increases % body fat, with largest increases in adiposity occurring when BCAAs are increased on a high protein, low carbohydrate dietary background. Finally, we found that increased dietary BCAAs were associated with increased food intake when the background diet was low in BCAAs. Our data highlights the interaction between BCAAs and background nutrition. We show that the effects of BCAAs on metabolic health cannot be studied in isolation but must be considered as part of complex mixture of dietary components.

Moving beyond body condition indices as an estimate of fitness in ecological and evolutionary studies

Publisher: Wiley

Date: 18-05-2016

DOI: 10.1111/1365-2435.12460

Drosophila as a useful model for understanding the evolutionary physiology of obesity resistance and metabolic thrift

Publisher: Informa UK Limited

Date: 02-01-2021

DOI: 10.1080/19336934.2021.1896960

Dietary restriction and aging: A unifying perspective

Publisher: Elsevier BV

Date: 08-2011

DOI: 10.1016/J.CMET.2011.06.013

Geometric analysis of macronutrient intake in humans: The power of protein?

Publisher: Elsevier BV

Date: 10-2003

DOI: 10.1016/S0195-6663(03)00049-7

Abstract: We introduce a state-space, geometrical approach that has previously been derived and tested using non-human animals and aim to demonstrate that it has the potential to generate testable hypotheses and provide novel insights into human nutrition and diet selection. This 'Geometric Framework' is unusual in that it focuses on the interactions between dietary constituents, and thus emphasizes the manner in which organisms regulate the balance of nutrients ingested. We report results from a pilot study, which indicate that protein ingestion is more strongly regulated than carbohydrate+fat. On the basis of these results and a brief survey of other experimental and population-level data, we hypothesize that regulation of protein intake may explain more of the modern human nutritional condition than has previously been appreciated.

Can the protein costs of bacterial resistance be offset by altered feeding behaviour?

Publisher: Wiley

Date: 09-02-2009

DOI: 10.1111/J.1365-2656.2008.01499.X

Abstract: 1. Mounting an immune response is likely to be costly in terms of energy and nutrients, and so it is predicted that dietary intake should change in response to infection to offset these costs. The present study focuses on the interactions between a specialist grass-feeding caterpillar species, the African armyworm Spodoptera exempta, and an opportunist bacterium, Bacillus subtilis. 2. The main aims of the study were (i) to establish the macronutrient costs to the insect host of surviving a systemic bacterial infection, (ii) to determine the relative importance of dietary protein and carbohydrate to immune system functions, and (iii) to determine whether there is an adaptive change in the host's normal feeding behaviour in response to bacterial challenge, such that the nutritional costs of resisting infection are offset. 3. We show that the survival of bacterially infected larvae increased with increasing dietary protein-to-carbohydrate (P:C) ratio, suggesting a protein cost associated with bacterial resistance. As dietary protein levels increased, there was an increase in antibacterial activity, phenoloxidase (PO) activity and protein levels in the haemolymph, providing a potential source for this protein cost. However, there was also evidence for a physiological trade-off between antibacterial activity and phenoloxidase activity, as larvae whose antibacterial activity levels were elevated in response to immune activation had reduced PO activity. 4. When given a choice between two diets varying in their P:C ratios, larvae injected with a sub-lethal dose of bacteria increased their protein intake relative to control larvae whilst maintaining similar carbohydrate intake levels. These results are consistent with the notion that S. exempta larvae alter their feeding behaviour in response to bacterial infection in a manner that is likely to enhance the levels of protein available for producing the immune system components and other factors required to resist bacterial infections ('self-medication').

Observations of the “Egg White Injury” in Ants

Publisher: Public Library of Science (PLoS)

Date: 13-11-2014

DOI: 10.1371/JOURNAL.PONE.0112801

Free amino acids as phagostimulants in cricket nuptial gifts: Support for the 'Candymaker' hypothesis

Publisher: The Royal Society

Date: 20-01-2009

DOI: 10.1098/RSBL.2008.0731

Abstract: Nuptial gifts that are manufactured by the male are found in numerous insect species and some spiders, but there have been very few studies of the composition of such gifts. If, as has been proposed recently, nuptial gifts represent sensory traps, males will be selected to produce gifts that are attractive to females but such gifts will not necessarily provide the female with nutritional benefits (the ‘Candymaker’ hypothesis). We examined the free amino acid content of the spermatophylax of the cricket Gryllodes sigillatus (Orthoptera: Gryllidae) using high performance liquid chromatography (HPLC). The spermatophylax (dry weight) consisted of approximately 7 per cent free amino acids. The free amino acid composition was highly imbalanced, with a low proportion of essential amino acids (18.7%) and a high proportion of proline and glycine. The main free amino acids found in the spermatophylax appeared to act as phagostimulants: the duration of feeding on artificial gels by females was positively related to the free amino acid content of the gels. The results therefore suggest that males use free amino acids to ‘sweeten’ a relatively low-value food item. A possible function of glycine in inhibiting female movement is also proposed.

Nutritional Physiology: Sex Elicits a Taste for Salt in Drosophila

Publisher: Elsevier BV

Date: 10-2015

DOI: 10.1016/J.CUB.2015.09.007

Abstract: Increased salt intake has been found to boost egg production in Drosophila. Females develop a specific appetite for salt following mating. This is not triggered by demand for sodium from developing eggs, but by release of a Sex Peptide into the female's reproductive tract by the male during mating.

The role of volumetric feedback from the hindgut in the regulation of meal size in fifth‐instar Locusta migratoria nymphs

Publisher: Wiley

Date: 12-1983

DOI: 10.1111/J.1365-3032.1983.TB00380.X

Stimuli inducing gregarious colouration and behaviour in nymphs of Schistocerca gregaria

Publisher: Elsevier BV

Date: 07-2005

DOI: 10.1016/J.JINSPHYS.2005.03.015

Abstract: Solitarious nymphs of Schistocerca gregaria were reared under various conditions in both Jerusalem and Oxford to tease apart cues involved in behavioural and colour phase change. Treatments included rearing nymphs from the IInd or IIIrd until the final nymphal stadium in physical contact with similarly aged conspecific groups or with another locust species, Locusta migratoria migratorioides, as well as confining single nymphs in mesh cages, which were kept within crowds of S. gregaria or L. migratoria migratorioides, providing visual and olfactory but no physical contact with other locusts. In the Oxford experiments, an extra treatment was included which provided olfactory cues without visual or contact stimulation. Our results confirm that transformation from the solitarious to the gregarious phase of locusts is complex, and that different phase characteristics not only follow different time courses, but are also controlled by different suites of cues. As predicted from earlier studies, behavioural phase change was evoked by non-species-specific cues. Rearing in contact with either species was fully effective in inducing gregarious behaviour, as was the combination of the sight and smell of other locusts, but odour alone was ineffective. Colour phase change was shown to comprise two distinct elements that could be dissociated: black patterning and yellow background. The former of these could be induced as effectively by rearing S. gregaria nymphs in a crowd of L. migratoria migratorioides as by rearing with conspecifics. Sight and smell of other locusts also triggered black patterning and, unlike behavioural change, some black patterning was induced by odour cues alone. Hence, physical contact was not needed to induce gregarious black patterning. Yellow colouration, however, was only fully induced when locusts were reared in contact with conspecifics, implying the presence of a species-specific contact chemical cue.

Eight polymorphic microsatellite loci for the Australian plague locust, Chortoicetes terminifera

Publisher: Wiley

Date: 29-10-2008

DOI: 10.1111/J.1755-0998.2008.02204.X

Abstract: Few population genetics studies have been carried out on major locust species. In particular, an understanding of the population genetic structure of the Australian plague locust, Chortoicetes terminifera, is lacking. We isolated and characterized eight polymorphic microsatellite loci in C. terminifera, and described experimental conditions for polymerase chain reaction multiplexing and genotyping these loci. The number of alleles per locus ranged from 11 to 29 and the expected heterozygosity ranged from 0.797 to 0.977. One locus was found to be X-linked. Results of cross-taxon lification tests are reported in four species of the Oedipodinae subfamily.

Food, culture, and sociality in Drosophila

Publisher: Frontiers Media SA

Date: 2012

DOI: 10.3389/FPSYG.2012.00165

Cardio-metabolic effects of high-fat diets and their underlying mechanisms—a narrative review

Publisher: MDPI AG

Date: 21-05-2020

DOI: 10.3390/NU12051505

Abstract: The majority of the epidemiological evidence over the past few decades has linked high intake of fats, especially saturated fats, to increased risk of diabetes and cardiovascular disease. However, findings of some recent studies (e.g., the PURE study) have contested this association. High saturated fat diets (HFD) have been widely used in rodent research to study the mechanism of insulin resistance and metabolic syndrome. Two separate but somewhat overlapping models—the diacylglycerol (DAG) model and the ceramide model—have emerged to explain the development of insulin resistance. Studies have shown that lipid deposition in tissues such as muscle and liver inhibit insulin signaling via the toxic molecules DAG and ceramide. DAGs activate protein kinase C that inhibit insulin-PI3K-Akt signaling by phosphorylating serine residues on insulin receptor substrate (IRS). Ceramides are sphingolipids with variable acyl group chain length and activate protein phosphatase 2A that dephosphorylates Akt to block insulin signaling. In adipose tissue, obesity leads to infiltration of macrophages that secrete pro-inflammatory cytokines that inhibit insulin signaling by phosphorylating serine residues of IRS proteins. For cardiovascular disease, studies in humans in the 1950s and 1960s linked high saturated fat intake with atherosclerosis and coronary artery disease. More recently, trials involving Mediterranean diet (e.g., PREDIMED study) have indicated that healthy monounsaturated fats are more effective in preventing cardiovascular mortality and coronary artery disease than are low-fat, low-cholesterol diets. Antioxidant and anti-inflammatory effects of Mediterranean diets are potential mediators of these benefits.

Nutrients, not caloric restriction, extend lifespan in Queensland fruit flies (Bactrocera tryoni)

Publisher: Wiley

Date: 24-09-2009

DOI: 10.1111/J.1474-9726.2009.00497.X

Abstract: Caloric restriction (CR) has been widely accepted as a mechanism explaining increased lifespan (LS) in organisms subjected to dietary restriction (DR), but recent studies investigating the role of nutrients have challenged the role of CR in extending longevity. Fuelling this debate is the difficulty in experimentally disentangling CR and nutrient effects due to compensatory feeding (CF) behaviour. We quantified CF by measuring the volume of solution imbibed and determined how calories and nutrients influenced LS and fecundity in unmated females of the Queensland fruit fly, Bactocera tryoni (Diptera: Tephritidae). We restricted flies to one of 28 diets varying in carbohydrate:protein (C:P) ratios and concentrations. On imbalanced diets, flies overcame dietary dilutions, consuming similar caloric intakes for most dilutions. The response surface for LS revealed that increasing C:P ratio while keeping calories constant extended LS, with the maximum LS along C:P ratio of 21:1. In general, LS was reduced as caloric intake decreased. Lifetime egg production was maximized at a C:P ratio of 3:1. When given a choice of separate sucrose and yeast solutions, each at one of five concentrations (yielding 25 choice treatments), flies regulated their nutrient intake to match C:P ratio of 3:1. Our results (i) demonstrate that CF can overcome dietary dilutions (ii) reveal difficulties with methods presenting fixed amounts of liquid diet (iii) illustrate the need to measure intake to account for CF in DR studies and (iv) highlight nutrients rather than CR as a dominant influence on LS.

Predator Percolation, Insect Outbreaks, and Phase Polyphenism

Publisher: Elsevier BV

Date: 2009

DOI: 10.1016/J.CUB.2008.10.070

Abstract: Apart from being notorious outbreak pests, locusts are of interest because of their expression of density-dependent "phase polyphenism." In this remarkable form of phenotypic plasticity, changes in local population density generate distinct solitarious and gregarious phases that differ in behavior, physiology, and appearance. A hallmark of phase polyphenism in outbreak species is the transition from solitary living to group formation and subsequent mass movement in migratory bands or swarms, yet there has been no convincing general explanation for the evolution of these density-dependent switches in spatial distribution. Using a model from "percolation theory", we show that it would be highly detrimental for locust in iduals to continue indefinitely in a dispersed spatial distribution as their population densities increase. Switching to an extremely clumped distribution is advantageous because it disrupts the connectivity of predators' food-patch networks. Thus, selection pressure from predators has probably been an important factor underlying the initial evolution of conditional switches between "dispersed" and strongly aggregative behavior, which will also affect outbreak dynamics. Although group formation is the best alternative for high-density populations, it brings its own set of severe problems, resulting in secondary selection for many of the traits seen in gregarious-phase in iduals.

Protein appetite as an integrator in the obesity system: the protein leverage hypothesis

Publisher: The Royal Society

Date: 04-09-2023

DOI: 10.1098/RSTB.2022.0212

Evidence for widespread genomic methylation in the migratory locust, Locusta migratoria (Orthoptera: Acrididae).

Publisher: Public Library of Science (PLoS)

Date: 05-12-2011

DOI: 10.1371/JOURNAL.PONE.0028167

Threats to an ecosystem service: pressures on pollinators

Publisher: Wiley

Date: 06-2013

DOI: 10.1890/120126

The interplay between PCOS pathology and diet on gut microbiota in a mouse model

Publisher: Informa UK Limited

Date: 04-07-2022

DOI: 10.1080/19490976.2022.2085961

University Of Oxford

Location: United Kingdom of Great Britain and Northern Ireland

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University Of Queensland

Location: Australia

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University Of Sydney

Location: Australia

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Jesus College, University Of Oxford

Location: No location found

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Jesus College, University Of Oxford

Location: United Kingdom of Great Britain and Northern Ireland

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University Of London

Location: United Kingdom of Great Britain and Northern Ireland

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Australian Centre Of Excellence In Twin Research

Start Date: 2014

End Date: 2019

Funder: National Health and Medical Research Council

Defining Factors That Contribute To Individual Diversity In The Diet-health Axis

Start Date: 2015

End Date: 2019

Funder: National Health and Medical Research Council

Defining And Treating The Physiological Effects Of Bushfire Smoke Exposure

Start Date: 2020

End Date: 2023

Funder: Department of Health

Dietary Nutrients, Variety And The Control Of Human Energy Intake

Start Date: 2011

End Date: 2013

Funder: National Health and Medical Research Council

Ancestral Causes Of Obesity: Understanding Epigenetic Transmission By Spermatozoa

Start Date: 2019

End Date: 2024

Funder: Novo Nordisk Fonden

Nourishing Australia: A Decadal Plan For Nutrition Science

Start Date: 2018

End Date: 2018

Funder: Australian Research Council

Structure Et Efficacité Des Réseaux De Pollinisation Dans Des Environnements Changeants

Start Date: 2017

End Date: 2020

Funder: Agence Nationale de la Recherche

Reducing Salt Intake Using Food Policy Interventions

Start Date: 2016

End Date: 2021

Funder: National Health and Medical Research Council

Nutrition And Complexity

Start Date: 2019

End Date: 2023

Funder: National Health and Medical Research Council

How FGF21 Regulates Protein Intake

Start Date: 2016

End Date: 2018

Funder: Australian Research Council

Nutritional Dynamics: From Genes To Individuals To Ecosystems

Start Date: 2009

End Date: 2014

Funder: Australian Research Council

A Systems Biology Capability For The Ramaciotti Centre For Genomics

Start Date: 2016

End Date: 2016

Funder: Australian Research Council

Making Green Guard® Greener: Enhancing The Efficacy Of A Biopesticide

Start Date: 2015

End Date: 2018

Funder: Australian Research Council

Molecular Pathways Linking Nutrition And Age-related Health

Start Date: 2016

End Date: 2018

Funder: National Health and Medical Research Council

Functional Genomics Approach To Extend Lifespan While Preventing Age - Related Cognitive Decline

Start Date: 2016

End Date: 2019

Funder: National Health and Medical Research Council

Ageing And Late Life Health: Calories, Macronutrients Or Branched Chain Amino Acids

Start Date: 2015

End Date: 2017

Funder: National Health and Medical Research Council

Integrative Behaviour: A New Synthesis

Start Date: 2004

End Date: 2009

Funder: Australian Research Council

On The Move: The Study Of Self-organised Movement Of Animal Groups With And Without Leadership

Start Date: 2006

End Date: 2008

Funder: Australian Research Council

Australian Plague Locust Population Genetics And Migratory Behaviour

Start Date: 2007

End Date: 2010

Funder: Australian Research Council

Climate Controlled Physical Containment 2 (PC2) And Pathogen/insect Contained Glasshouse Facility

Start Date: 2007

End Date: 2007

Funder: Australian Research Council

Video Analysis Suite For The Integrative Analysis Of Resource Acquisition Behaviour In Animals

Start Date: 2008

End Date: 2008

Funder: Australian Research Council

The Functional Genomics Of Locust Migratory Behaviour

Start Date: 2008

End Date: 2010

Funder: Australian Research Council

Heterarchical Modelling Of Nutritional Ecology: From Individuals To Communities

Start Date: 2009

End Date: 2011

Funder: Australian Research Council

Autonomous Tracking And Predictive Modelling Of Australian Plague Locust Migratory Band Movement

Start Date: 2009

End Date: 2011

Funder: Australian Research Council

(Advanced High Resolution Mass Spectrometer For Collaborative Proteomic And Lipidomics Research)

Start Date: 2013

End Date: 2013

Funder: Australian Research Council

Testing The Protein Leverage Hypothesis In Humans

Start Date: 2007

End Date: 2009

Funder: National Health and Medical Research Council

The Nutritional Geometry Of Ageing In A Rodent Model

Start Date: 2009

End Date: 2013

Funder: National Health and Medical Research Council

A Multiple Ion Beam Facility For Microscopy And Nanofabrication

Start Date: 2017

End Date: 2017

Funder: Australian Research Council

Dining With Dasyurids: Using Nutritional Geometry To Improve Diets For Captive Breeding Programs

Start Date: 2015

End Date: 2017

Funder: Australian Research Council

Nutritional And Bacterial Influences On Gut And Peripheral Homeostasis

Start Date: 2017

End Date: 2021

Funder: Australian Research Council

Federation Fellowships - Grant ID: FF0456170

Start Date: 2005

End Date: 12-2009

Amount: $1,519,710.00

Funder: Australian Research Council

Australian Laureate Fellowships - Grant ID: FL0992270

Start Date: 12-2009

End Date: 12-2014

Amount: $3,080,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP150100479

Start Date: 02-2016

End Date: 06-2018

Amount: $385,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP160101119

Start Date: 2016

End Date: 12-2018

Amount: $379,400.00

Funder: Australian Research Council

Learned Academies Special Projects - Grant ID: LA170100022

Start Date: 07-2017

End Date: 12-2020

Amount: $118,098.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP0664709

Start Date: 02-2006

End Date: 02-2009

Amount: $500,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP140100235

Start Date: 02-2015

End Date: 05-2017

Amount: $284,500.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP130103222

Start Date: 07-2013

End Date: 06-2016

Amount: $432,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP220200115

Start Date: 07-2023

End Date: 06-2026

Amount: $790,276.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE160100204

Start Date: 2016

End Date: 12-2016

Amount: $550,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE170100140

Start Date: 2017

End Date: 12-2018

Amount: $1,050,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE130100096

Start Date: 2013

End Date: 01-2014

Amount: $235,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP0985137

Start Date: 05-2009

End Date: 10-2013

Amount: $390,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP0669080

Start Date: 03-2007

End Date: 12-2010

Amount: $399,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE120100177

Start Date: 08-2012

End Date: 08-2013

Amount: $150,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP160100627

Start Date: 06-2017

End Date: 06-2021

Amount: $600,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE110100134

Start Date: 2011

End Date: 12-2011

Amount: $160,240.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE0775702

Start Date: 07-2008

End Date: 07-2008

Amount: $337,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE0883055

Start Date: 02-2008

End Date: 10-2008

Amount: $170,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP0989291

Start Date: 05-2009

End Date: 12-2013

Amount: $340,000.00

Funder: Australian Research Council