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No description available.

The increase in rates of obesity and overweight in the UK have been attributed, in part, to dietary factors. One possibility is caloric beverage consumption contributes to weight gain through weakened satiety and energy compensation. However, it is unclear if this claim applies to all beverage types and consumption conditions. This thesis investigated if the satiating effects of protein compared to carbohydrate are diminished in a between meal drink context.

Obesity presents a major public health burden with prevalence rising in both children and adults. This disorder is associated with many adverse health outcomes and improved understanding of the mechanisms is required to develop effective preventive and treatment strategies. It has been hypothesised that environmental exposures such as poor nutrition in utero and during the early post natal period can programme an individual to develop obesity in later life. These early life exposures can be ‘memorised’ by the cell in the form of epigenetic modifications, changes to the biochemical structure and function of DNA. Such modifications include DNA methylation, the addition of a methyl group to cytosine residues which is involved in the regulation of gene transcription. Epigenetic mechanisms therefore represent an attractive mechanism to explain developmental programming phenomena. The overarching aim of this study was to establish the mediating role of epigenetic processes in linking modifiable environmental exposures with subsequent risk of obesity. This was addressed through interrogation of animal models, through the development and application of bioinformatic approaches and through epidemiological investigation of human population studies. Tissue level DNA methylation patterns were investigated in hypothalamus using immunohistochemical staining. No significant differences were discernible between methylation levels in the hypothalami of control rodents when compared to hypothalami from rodents that had been exposed in utero to a dietary regimen that induces metabolic perturbation and obesity in offspring. Bioinformatic approaches were used to develop and apply an in silico workflow to interrogate gene expression dataset, in this instance from a rodent model of dietary manipulation in utero and early postnatal life. The purpose of this in silico interrogation was to identify loci that were strong candidates for epigenetic regulation of gene expression. Four genes, Esr1, Fxn, Igf2r and Rbl2 were identified and the levels of promoter methylation at these loci were assessed in rodent liver tissue from offspring of exposed and unexposed mothers using pyrosequencing. DNA methylation levels in Igf2r were observed to be higher in animals exposed to a maternal obesogenic diet.

Obesity and overweight are global issues and the rate of obesity has more than doubled in the past 30 years. The financial and physical cost of obesity and overweight continues to rise. Obesity and overweight are characterised as relapsing conditions which can share psychopathology with eating disorders. This thesis intended to evaluate current psychological approaches to obesity and overweight which was under-researched. It explored a compassionate mind approach intervention for weight management which focused on psychosocial factors present in obesity and overweight. The systematic literature review evaluated psychological interventions for the treatment of obesity and overweight. Twelve articles were reviewed and assessed for methodological quality. The results demonstrated short-term treatment efficacy for behavioural therapy but the evidence for the most effective form of psychological intervention was inconclusive. There was no conclusive evidence that psychological interventions offered long-term weight-loss maintenance. A requirement for further research into psychological interventions for obesity and overweight using robust methodology was indicated. Methodological issues were considered which may have limited the conclusions of the review. The empirical study was a randomised control trial that lasted for six months. Thirty six participants received either compassionate mind approach guided self-help (GSH) or treatment as usual (TAU) in a dietetic clinic. Measures of shame, self-compassion, psychological wellbeing, disordered eating, physical activity and BMI were taken at pre and post-intervention. No statistically significant results were demonstrated for GSH or TAU in terms of these factors. Treatment effect sizes were observed for GSH regarding levels of external shame, self-compassion and preoccupation with shape and for TAU regarding levels of uncontrolled eating. The results suggested that eating psychopathology and psychosocial factors are relevant in treatment seeking obese populations and these should be explored when developing interventions. The study limitations, clinical implications and future research were discussed.

Obesity and weight-management is primarily focused on improving diet, nutrition and activity levels. Some research suggests that psychological interventions may have a role in weight-management. This thesis sought to better understand whether there is a role for the use of psychological approaches in obesity. Literature Review: A review of literature examining the efficacy of cognitive-behavioural therapy (CBT) as a treatment for weight management was conducted. Ten quantitative studies were included in the review. The evidence showed that CBT had a positive effect on weight-loss in both short and long-term studies and was superior to treatment as usual, minimal or no treatment conditions. The literature was critically appraised and clinical implications were discussed. Research Report: The empirical paper examined the role of self-conscious emotions, such as shame, self-esteem and self-compassion along with psychological distress. These have emerged as important factors in the development and maintenance of eating disorders. These were investigated with regards to their relationship with eating behaviours (emotional eating, uncontrolled eating and restraint), as well as eating disorder psychopathology in a clinically obese population. Treatment-seeking obese adults (N=53) were recruited from a dietetic clinic and a range of psychometric measures completed. High levels of shame, distress and eating disorder psychopathology were shown when compared to other non-clinical populations. Results showed high levels of uncontrolled eating, and emotional eating. Internal shame was shown to have a unique contribution in the explanation of emotional eating. A number of significant positive correlations were found with shame, including emotional and uncontrolled eating. Although the sample size was small, the results indicated that shame might have an important role in eating behaviours. Psychological interventions addressing self-conscious negative emotions may be useful in weight management interventions.

No description available.

Obesity is a growing epidemic in the United Kingdom. An important contributor to cardiovascular disease, obesity is responsible for a growing proportion of morbidity and mortality in England, and poses a sizable burden on the UK's National Health Service. Ethnic minority and socioeconomically disadvantaged populations have been shown to have higher risk for obesity compared to whites and socioeconomically privileged populations. However, little is known about intervention strategies that can curb the epidemic and decrease inequalities in obesity. Currently, the literature about obesity and its unequal burden has relied on traditional epidemiologic regression techniques, which may not be equipped to unravel the complex social causes of obesity in ethnically and socioeconomically diverse contexts. Rather, systems approaches, such as agent-based modelling, may be well poised for studying health in a complex, heterogeneous population that features changing and adaptive behaviors and interactions between individuals and between individuals and their environments. I used agent-based modelling to shed light on the aetiology of obesity and its inequalities in England in hopes of educating strategies for intervention against this epidemic. After I systematically reviewed the literatures about ethnic and socioeconomic inequalities in obesity in the United Kingdom, I reviewed and synthesized the literature about the use of systems approaches, including social network analysis and agent-based modelling, in social epidemiology. I then developed, constructed, and implemented the Obesagent model, an agent-based model of obesity in England. Using this model, I first showed that life course trajectories in obesity produced by the model were comparable to those from real data. I then assessed life course trajectories in ethnic and socioeconomic inequalities in obesity and demonstrated that higher obesity rates among Blacks may arise during childhood. Second, I explored the effectiveness of various curative and preventive intervention strategies against obesity in this context. Third, I demonstrated that given their relatively small effect relative to other exposures in the aetiology of obesity, targeting social networks in anti-obesity interventions is not likely to improve their efficacy. Fourth, I used the model to demonstrate that interventions against neighbourhood and social segregation may not substantially decrease ethnic inequalities in obesity in England. I conclude with a synthesis of this work, a discussion of its implications for anti-obesity policy in England, and suggested directions for future research.