Why do we overeat from larger portions? Plate-clearing tendencies and food waste concerns as potential explanations

This thesis investigated how plate-clearing tendencies and food waste concerns may contribute to overconsumption from larger portion sizes of food. Chapter 2 demonstrated that, irrespective of the portion size served, those who self-reported a tendency to plate-clear when eating consumed significantly more food than those who reported low plate-clearing tendencies. Chapter 3 demonstrated the reliability and validity of a new scale to measure food waste concerns in an eating context. Scores on this scale positively predicted self-reported plate-clearing tendencies, but were not predictive of objectively measured energy intake, BMI or the likelihood of having overweight. Chapter 4 reports on studies in which beliefs about food waste were manipulated. Across Chapters 3 and 4, there was little evidence that food waste concerns influenced objectively measured food intake. Chapter 5 showed that plate-clearing tendencies and food waste concerns moderate the influence portion size has on intended food consumption. Given that intended consumption predicts actual consumption, individuals who are concerned about wasting food and habitually clear their plate may be at risk of overeating, especially when faced with larger portions. This thesis provides further evidence for a portion size effect on intended and actual consumption, with implications for policies and interventions aimed at reducing the size of portions available in our food environment. It also provides the first thorough investigation into how plate-clearing tendencies and food waste concerns influence food intake. My findings suggest that working to create a food environment in which plate-clearing would no longer constitute a maladaptive behaviour could induce widespread reductions in food intake. I also provide further evidence that food waste concerns are associated with plate-clearing tendencies. Further investigation into how food waste concerns influence plate-clearing tendencies, and how this may influence eating behaviour, is now warranted

Nighttime assaults: using a national emergency department monitoring system to predict occurrence, target prevention and plan services

Background: Emergency department (ED) data have the potential to provide critical intelligence on when violence is most likely to occur and the characteristics of those who suffer the greatest health impacts. We use a national experimental ED monitoring system to examine how it could target violence prevention interventions towards at risk communities and optimise acute responses to calendar, holiday and other celebration-related changes in nighttime assaults. Methods: A cross-sectional examination of nighttime assault presentations (6.01 pm to 6.00 am; n = 330,172) over a three-year period (31st March 2008 to 30th March 2011) to English EDs analysing changes by weekday, month, holidays, major sporting events, and demographics of those presenting. Results: Males are at greater risk of assault presentation (adjusted odds ratio [AOR] 3.14, 95% confidence intervals [CIs] 3.11-3.16; P < 0.001); with male:female ratios increasing on more violent nights. Risks peak at age 18 years. Deprived individuals have greater risks of presenting across all ages (AOR 3.87, 95% CIs 3.82-3.92; P < 0.001). Proportions of assaults from deprived communities increase midweek. Female presentations in affluent areas peak aged 20 years. By age 13, females from deprived communities exceed this peak. Presentations peak on Friday and Saturday nights and the eves of public holidays; the largest peak is on New Year’s Eve. Assaults increase over summer with a nadir in January. Impacts of annual celebrations without holidays vary. Some (Halloween, Guy Fawkes and St Patrick’s nights) see increased assaults while others (St George’s and Valentine’s Day nights) do not. Home nation World Cup football matches are associated with nearly a three times increase in midweek assault presentation. Other football and rugby events examined show no impact. The 2008 Olympics saw assaults fall. The overall calendar model strongly predicts observed presentations (R2 = 0.918; P < 0.001). Conclusions: To date, the role of ED data has focused on helping target nightlife police activity. Its utility is much greater; capable of targeting and evaluating multi-agency life course approaches to violence prevention and optimising frontline resources. National ED data are critical for fully engaging health services in the prevention of violence

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Diversity among flexitarian consumers; stratifying meat reducers by their underlying motivations to move to a plant-based diet

Concerns surrounding environmental and health impacts of meat production and consumption have motivated consumers to reduce their intake of animal-based products, with many adopting a ‘flexitarian’ diet that involves reduction of animal-based products, without complete abstinence. The underlying motivations driving this dietary shift remain unclear.  Two online studies investigated whether subgroups of flexitarian consumers could be identified through individual differences in psychological traits that were hypothesised to be related to flexitarianism. Consumer subgroups were compared on their self-reported meat consumption and factors important to their dietary choices.  In Study 1, self-identified flexitarians (N = 353) completed questionnaires comprising validated items related to psychological aspects of food choices (e.g., food-neophobia, food-involvement, health-consciousness). Consumer segments were created based on clusters of differences in motivations to follow a flexitarian diet. Study 2 (N = 297) sought to validate these initial clusters in a naïve sample of self-identified flexitarians.  In Study 1, consumers grouped into three distinct clusters defined as ‘health-driven’, ‘trend-cautious’, and ‘adventurous’ flexitarians. Differences in food choice motivations and the importance of reducing meat intake were observed between clusters, but not reflected in differences in meat consumption. In Study 2, four consumer segments were defined as ‘health-only’, ‘traditional trend-cautious’, ‘adventurous’ and ‘health-focused’ flexitarians. Again, differences in food motivations, health interest, justifications for meat consumption and the importance of reducing meat intake were observed between clusters, but not reflected in differences in meat consumption.  We provide a novel description of the diverse motivations among flexitarian consumers to reduce animal-based product intake.</p

A bit or a lot on the side? Observational study of the energy content of starters, sides and desserts in major UK restaurant chains

Objectives Our objective was to examine the kilocalorie (kcal) content of starters, sides and desserts served in major UK restaurant chains, comparing the kcal content of these dishes in fast-food and full-service restaurants. Design Observational study. Setting Menu and nutritional information provided online by major UK restaurant chains. Method During October to November 2018, we accessed websites of restaurant chains with 50 or more outlets in the UK. Menu items that constituted starters, sides or desserts were identified and their kcal content was extracted. Accompanying beverages were not included. We used multilevel modelling to examine whether mean kcal content of dishes differed in fast-food versus full-service restaurants. Main outcome measures The mean kcal content of dishes and the proportion of dishes exceeding public health recommendations for energy content in a main meal (>600 kcal). Results A total of 1009 dishes (212 starters, 318 sides and 479 desserts) from 27 restaurant chains (21 full-service, 6 fast-food) were included. The mean kcal content of eligible dishes was 488.0 (SE=15.6) for starters, 397.5 (SE=14.9) for sides and 430.6 (SE=11.5) for desserts. The percentage of dishes exceeding 600 kcal was 26.4% for starters, 21.7% for sides and 20.5% for desserts. Compared with fast-food chains, desserts offered at full-service restaurants were on average more calorific and were significantly more likely to exceed 600 kcal. Conclusions The average energy content of sides, starters and desserts sold in major UK restaurants is high. One in four starters and one in five sides and desserts in UK chain restaurants exceed the recommended energy intake for an entire meal