ORCID Profile
0000-0003-1629-3189
Current Organisation
University of Leeds
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Publisher: Elsevier BV
Date: 02-2016
Abstract: Several studies have assessed the effects of food and nonalcoholic beverage (hereafter collectively referred to as food) advertising on food consumption, but the results of these studies have been mixed. This lack of clarity may be impeding policy action. We examined the evidence for a relation between acute exposure to experimental unhealthy food advertising and food consumption. The study was a systematic review and meta-analysis of published studies in which advertising exposure (television or Internet) was experimentally manipulated, and food intake was measured. Five electronic databases were searched for relevant publications (SCOPUS, PsycINFO, MEDLINE, Emerald Insight, and JSTOR). An inverse variance meta-analysis was used whereby the standardized mean difference (SMD) in food intake was calculated between unhealthy food advertising and control conditions. Twenty-two articles were eligible for inclusion. Data were available for 18 articles to be included in the meta-analysis (which provided 20 comparisons). With all available data included, the analysis indicated a small-to-moderate effect size for advertising on food consumption with participants eating more after exposure to food advertising than after control conditions (SMD: 0.37 95% CI: 0.09 0.65 I(2) = 98%). Subgroup analyses showed that the experiments with adult participants provided no evidence of an effect of advertising on intake (SMD: 0.00 P = 1.00 95% CI: -0.08, 0.08 I(2) = 8%), but a significant effect of moderate size was shown for children, whereby food advertising exposure was associated with greater food intake (SMD: 0.56 P = 0.003 95% CI: 0.18, 0.94 I(2) = 98%). Evidence to date shows that acute exposure to food advertising increases food intake in children but not in adults. These data support public health policy action that seeks to reduce children's exposure to unhealthy food advertising.
Publisher: Elsevier BV
Date: 03-2019
Publisher: Palgrave Macmillan UK
Date: 2014
Publisher: Springer Science and Business Media LLC
Date: 12-02-2020
DOI: 10.1186/S12966-020-0920-4
Abstract: Smaller portions may help to reduce energy intake. However, there may be a limit to the magnitude of the portion size reduction that can be made before consumers respond by increasing intake of other food immediately or at later meals. We tested the theoretical prediction that reductions to portion size would result in a significant reduction to daily energy intake when the resulting portion was visually perceived as ‘normal’ in size, but that a reduction resulting in a ‘smaller than normal’ portion size would cause immediate or later additional eating. Over three 5-day periods, daily energy intake was measured in a controlled laboratory study using a randomized crossover design ( N = 30). The served portion size of the main meal component of lunch and dinner was manipulated in three conditions: ‘large-normal’ (747 kcal), ‘small-normal’ (543 kcal), and ‘smaller than normal’ (339 kcal). Perceived ‘normality’ of portion sizes was determined by two pilot studies. Ad libitum daily energy intake from all meals and snacks was measured. Daily energy intake in the ‘large-normal’ condition was 2543 kcals. Daily energy intake was significantly lower in the ‘small-normal’ portion size condition ( mean difference − 95 kcal/d, 95% CI [− 184, − 6], p = .04) and was also significantly lower in the ‘smaller than normal’ than the ‘small-normal’ condition ( mean difference − 210 kcal/d, 95% CI [− 309, − 111], p .001). Contrary to predictions, there was no evidence that the degree of additional food consumption observed was greater when portions were reduced past the point of appearing normal in size. Reductions to the portion size of main-meal foods resulted in significant decreases in daily energy intake. Additional food consumption did not offset this effect, even when portions were reduced to the point that they were no longer perceived as being normal in size. Prospectively registered protocol and analysis plan: osf.io/natws/ retrospectively registered: t2/show/NCT03811210 .
Publisher: Springer Science and Business Media LLC
Date: 03-04-2019
DOI: 10.1007/S11695-019-03823-6
Abstract: Bariatric surgery is an effective weight loss tool, but an under-communicated side effect may include the increased risk for alcohol problems. Few studies have examined contributors towards alcohol problems following surgery using a qualitative approach. Therefore, the current study aimed to generate insight informed by participants with problematic alcohol use following bariatric surgery, in comparison with participants without. Participants (14 females, n = 9 males, n = 5) completed semi-structured interviews using questions relating to alcohol use, relationship to food, support and surgical experiences. Thematic analysis was conducted to provide insight into the factors which influenced drinking behaviours that participants engaged in following bariatric surgery, and motivations for drinking or limiting alcohol. Five core themes were identified between both participants with and without problematic alcohol use: (1) drinking motivations, (2) self-image, (3) impact of restriction on eating behaviour, (4) support needs and (5) surgical preparedness. A sixth core theme ("resilience") was identified specifically amongst participants without problematic alcohol use. Divergent experiences, cognitions and behaviours formed sub-themes within the five core themes and highlighted the differences between participants with and without problematic alcohol use within the core themes. This study is the first to qualitatively assess themes relating to the development of problematic alcohol use after bariatric surgery while additionally using a comparison group without problematic alcohol use. The findings highlight key features which contribute to problematic alcohol use, as well as experiences and cognitions that may be helpful in preventing this phenomenon in bariatric populations.
Publisher: BMJ
Date: 20-05-2022
DOI: 10.1136/BMJ.O1285
Publisher: BMJ
Date: 2017
Publisher: S. Karger AG
Date: 2020
DOI: 10.1159/000505342
Abstract: Heterogeneity of interin idual and intrain idual responses to interventions is often observed in randomized, controlled trials for obesity. To address the global epidemic of obesity and move toward more personalized treatment regimens, the global research community must come together to identify factors that may drive these heterogeneous responses to interventions. This project, called OBEDIS (OBEsity Diverse Interventions Sharing – focusing on dietary and other interventions), provides a set of European guidelines for a minimal set of variables to include in future clinical trials on obesity, regardless of the specific endpoints. Broad adoption of these guidelines will enable researchers to harmonize and merge data from multiple intervention studies, allowing stratification of patients according to precise phenotyping criteria which are measured using standardized methods. In this way, studies across Europe may be pooled for better prediction of in iduals’ responses to an intervention for obesity – ultimately leading to better patient care and improved obesity outcomes.
Publisher: Wiley
Date: 11-04-2019
DOI: 10.1111/OBR.12840
Publisher: Wiley
Date: 05-09-2023
DOI: 10.1111/DOM.15257
Publisher: Wiley
Date: 03-05-2019
DOI: 10.1111/DOM.13752
Publisher: BMJ
Date: 07-2021
DOI: 10.1136/BMJOPEN-2020-045663
Abstract: The newer glucose-lowering therapies for type 2 diabetes (T2D), the glucagon-like peptide-1 receptor agonists (GLP1-RAs) and the sodium-glucose co-transporter 2 inhibitors (SGLT2i), have additional clinical benefits beyond improving glycaemic control promoting weight loss, addressing associated cardiovascular risk factors and reducing macrovascular and microvascular complications. Considering their independent mechanisms of actions, there is a potential for significant synergy with combination therapy, yet limited data exist. This 32-week randomised, double-blind, placebo-controlled trial will gain mechanistic insight into the effects of coadministration of exenatide QW, a weekly subcutaneous GLP1-RA, with dapagliflozin, a once daily oral SGLT2i, on the dynamic, adaptive changes in energy balance, total, regional and organ-specific fat mass and multiorgan insulin sensitivity. 110 obese patients with diagnosed T2D (glycated haemoglobin, HbA 1c ≥48 mmol/mol) will be treated for 32 weeks with dapagliflozin (10 mg once daily either alone or in combination with exenatide QW (2 mg once weekly) active treatments will be compared with a control group (placebo tablet and sham injection). The primary objective of the study is to compare the adjusted mean reduction in total body fat mass (determined by dual-energy X-ray absorptiometry, DEXA) from baseline following 32 weeks of treatment with exenatide QW and dapagliflozin versus dapagliflozin alone compared with control (placebo). Secondary outcome measures include changes in (1) energy balance (energy intake and energy expenditure measured by indirect calorimetry) (2) appetite (between and within meals) and satiety quotient (3) body composition including visceral adipose tissue, subcutaneous adipose tissue, liver and pancreatic fat. Exploratory outcome measures include metabolic changes in hepatic and peripheral insulin sensitivity (using a two-stage hyperinsulinaemic, euglycaemic cl ), central nervous system responses to food images using blood oxygen level-dependent (BOLD) functional MRI (fMRI) and changes in cardiovascular function (using transthoracic echocardiography, cardiac MR and duplex ultrasonography). This study has been approved by the North West Liverpool Central Research Ethics Committee (14/NW/1147) and is conducted in accordance with the Declaration of Helsinki and the Good Clinical Practice. Results from the study will be published in peer-reviewed scientific and open access journals and/or presented at scientific conferences and summarised for distribution to the participants. University of Liverpool. ISRCTN 52028580 EUDRACT number 2015-005242-60.
Publisher: Wiley
Date: 26-02-2021
DOI: 10.1111/NBU.12489
Abstract: Food systems are significant sources of global greenhouse gas emissions (GHGE). Since emission intensity varies greatly between different foods, changing food choices towards those with lower GHGE could make an important contribution to mitigating climate change. Public engagement events offer an opportunity to communicate these multifaceted issues and raise awareness about the climate change impact of food choices. An interdisciplinary team of researchers was preparing food and climate change educational activities for summer 2020. However, the COVID‐19 pandemic and lockdown disrupted these plans. In this paper, we report on shifting these events online over the month of June 2020. We discuss what we did and the reception to our online programme. We then reflect on and highlight issues that arose. These relate to: (1) the power dynamics of children, diet and climate change (2) mental health, diet and COVID‐19 (3) engaging the wider science, agriculture and food communities (4) the benefits of being unfunded and the homemade nature of this programme (5) the food system, STEAM (science, technology, engineering, arts and mathematics) and ersity and (6) how our work fits into our ongoing journey of food and climate change education.
Publisher: Cambridge University Press (CUP)
Date: 06-09-2019
DOI: 10.1017/S0007114519002307
Abstract: Reducing food portion size could reduce energy intake. However, it is unclear at what point consumers respond to reductions by increasing intake of other foods. We predicted that a change in served portion size would only result in significant additional eating within the same meal if the resulting portion size was no longer visually perceived as ‘normal’. Participants in two crossover experiments (Study 1: n 45 Study 2: n 37 adults, 51 % female) were served different-sized lunchtime portions on three occasions that were perceived by a previous s le of participants as ‘large-normal’, ‘small-normal’ and ‘smaller than normal’, respectively. Participants were able to serve themselves additional helpings of the same food (Study 1) or dessert items (Study 2). In Study 1 there was a small but significant increase in additional intake when participants were served the ‘smaller than normal’ compared with the ‘small-normal’ portion ( m difference = 161 kJ, P = 0·002, d = 0·35), but there was no significant difference between the ‘small-normal’ and ‘large-normal’ conditions ( m difference = 88 kJ, P = 0·08, d = 0·24). A similar pattern was observed in Study 2 ( m difference = 149 kJ, P = 0·06, d = 0·18 m difference = 83 kJ, P = 0·26, d = 0·10). However, smaller portion sizes were each associated with a significant reduction in total meal intake. The findings provide preliminary evidence that reductions that result in portions appearing ‘normal’ in size may limit additional eating, but confirmatory research is needed.
Publisher: Elsevier BV
Date: 2021
Publisher: American Public Health Association
Date: 09-2010
Abstract: Objectives. We compared television food advertising to children in several countries. Methods. We undertook a collaboration among 13 research groups in Australia, Asia, Western Europe, and North and South America. Each group recorded programming for 2 weekdays and 2 weekend days between 6:00 and 22:00, for the 3 channels most watched by children, between October 2007 and March 2008. We classified food advertisements as core (nutrient dense, low in energy), noncore (high in undesirable nutrients or energy, as defined by dietary standards), or miscellaneous. We also categorized thematic content (promotional characters and premiums). Results. Food advertisements composed 11% to 29% of advertisements. Noncore foods were featured in 53% to 87% of food advertisements, and the rate of noncore food advertising was higher during children's peak viewing times. Most food advertisements containing persuasive marketing were for noncore products. Conclusions. Across all s led countries, children were exposed to high volumes of television advertising for unhealthy foods, featuring child-oriented persuasive techniques. Because of the proven connections between food advertising, preferences, and consumption, our findings lend support to calls for regulation of food advertising during children's peak viewing times.
Publisher: Elsevier BV
Date: 09-2021
Publisher: Springer Science and Business Media LLC
Date: 18-04-2018
DOI: 10.1007/S00125-018-4603-5
Abstract: Low physical activity levels and sedentary behaviour are associated with obesity, insulin resistance and type 2 diabetes. We investigated the effects of a short-term reduction in physical activity with increased sedentary behaviour on metabolic profiles and body composition, comparing the effects in in iduals with first-degree relatives with type 2 diabetes (FDR+ve) vs those without (FDR-ve). Forty-five habitually active participants (16 FDR+ve [10 female, 6 male] and 29 FDR-ve [18 female, 11 male] age 36 ± 14 years) were assessed at baseline, after 14 days of step reduction and 14 days after resuming normal activity. We determined physical activity (using a SenseWear armband), cardiorespiratory fitness ([Formula: see text]), body composition (dual-energy x-ray absorptiometry/magnetic resonance spectroscopy) and multi-organ insulin sensitivity (OGTT) at each time point. Statistical analysis was performed using a two-factor between-groups ANCOVA, with data presented as mean ± SD or (95% CI). There were no significant between-group differences in physical activity either at baseline or following step reduction. During the step-reduction phase, average daily step count decreased by 10,285 steps (95% CI 9389, 11,182 p < 0.001), a reduction of 81 ± 8%, increasing sedentary time by 223 min/day (151, 295 p < 0.001). Pooling data from both groups, following step reduction there was a significant decrease in whole-body insulin sensitivity (Matsuda index) (p < 0.001), muscle insulin sensitivity index (p < 0.001), cardiorespiratory fitness (p = 0.002) and lower limb lean mass (p = 0.004). Further, there was a significant increase in total body fat (p < 0.001), liver fat (p = 0.001) and LDL-cholesterol (p = 0.013), with a borderline significant increase in NEFA AUC during the OGTT (p = 0.050). Four significant between-group differences were apparent: following step reduction, FDR+ve participants accumulated 1.5% more android fat (0.4, 2.6 p = 0.008) and increased triacylglycerol by 0.3 mmol/l (0.1, 0.6 p = 0.044). After resuming normal activity, FDR+ve participants engaged in lower amounts of vigorous activity (p = 0.006) and had lower muscle insulin sensitivity (p = 0.023). All other changes were reversed with no significant between-group differences. A short-term reduction in physical activity with increased sedentary behaviour leads to a reversible reduction in multi-organ insulin sensitivity and cardiorespiratory fitness, with concomitant increases in central and liver fat and dyslipidaemia. The effects are broadly similar in FDR+ve and FDR-ve in iduals. Public health recommendations promoting physical activity should incorporate advice to avoid periods of sedentary behaviour.
Publisher: Elsevier BV
Date: 09-2021
Publisher: Frontiers Media SA
Date: 09-04-2021
DOI: 10.3389/FPHYS.2021.659834
Abstract: This study examined the effects of a short-term reduction in physical activity, and subsequent resumption, on metabolic profiles, body composition and cardiovascular (endothelial) function. Twenty-eight habitually active (≥10,000 steps/day) participants (18 female, 10 male age 32 ± 11 years BMI 24.3 ± 2.5 kg/m 2 ) were assessed at baseline, following 14 days of step-reduction and 14 days after resuming habitual activity. Physical activity was monitored throughout (SenseWear Armband). Endothelial function (flow mediated dilation FMD), cardiorespiratory fitness ( V . O 2 peak) and body composition including liver fat (dual-energy x-ray absorptiometry and magnetic resonance spectroscopy) were determined at each assessment. Statistical analysis was performed using one-way within subject’s ANOVA data presented as mean (95% CI). Participants decreased their step count from baseline by 10,111 steps/day (8949, 11,274 P & 0.001), increasing sedentary time by 103 min/day (29, 177 P & 0.001). Following 14 days of step-reduction, endothelial function was reduced by a 1.8% (0.4, 3.3 P = 0.01) decrease in FMD. Following resumption of habitual activity, FMD increased by 1.4%, comparable to the baseline level 0.4% (–1.8, 2.6 P = 1.00). Total body fat, waist circumference, liver fat, whole body insulin sensitivity and cardiorespiratory fitness were all adversely affected by 14 days step-reduction ( P & 0.05) but returned to baseline levels following resumption of activity. This data shows for the first time that whilst a decline in endothelial function is observed following short-term physical inactivity, this is reversed on resumption of habitual activity. The findings highlight the need for public health interventions that focus on minimizing time spent in sedentary behavior.
Publisher: Elsevier BV
Date: 09-2021
Publisher: S. Karger AG
Date: 2021
DOI: 10.1159/000513042
Abstract: There is substantial evidence documenting the effects of behavioural interventions on weight loss (WL). However, behavioural approaches to initial WL are followed by some degree of longer-term weight regain, and large trials focusing on evidence-based approaches to weight loss maintenance (WLM) have generally only demonstrated small beneficial effects. The current state-of-the-art in behavioural interventions for WL and WLM raises questions of (i) how we define the relationship between WL and WLM, (ii) how energy balance (EB) systems respond to WL and influence behaviours that primarily drive weight regain, (iii) how intervention content, mode of delivery and intensity should be targeted to keep weight off, (iv) which mechanisms of action in complex interventions may prevent weight regain and (v) how to design studies and interventions to maximise effective longer-term weight management. In considering these issues a writing team within the NoHoW Consortium was convened to elaborate a position statement, and behaviour change and obesity experts were invited to discuss these positions and to refine them. At present the evidence suggests that developing the skills to self-manage EB behaviours leads to more effective WLM. However, the effects of behaviour change interventions for WL and WLM are still relatively modest and our understanding of the factors that disrupt and undermine self-management of eating and physical activity is limited. These factors include physiological resistance to weight loss, gradual compensatory changes in eating and physical activity and reactive processes related to stress, emotions, rewards and desires that meet psychological needs. Better matching of evidence-based intervention content to quantitatively tracked EB behaviours and the specific needs of in iduals may improve outcomes. Improving objective longitudinal tracking of energy intake and energy expenditure over time would provide a quantitative framework in which to understand the dynamics of behaviour change, mechanisms of action of behaviour change interventions and user engagement with intervention components to potentially improve weight management intervention design and evaluation.
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Jason Christian Grovenor Halford.