The aims of the studies were to assess body image perceptions, the role of stress and other possible associated psychopathologies within a non-clinical sample. The prevalence of body image concern is increasing and is widely considered as secondary to evolving socio-cultural trends. Negative self-perceptions about body image can be manifest as measurable indicators of physiological stress, or even psychopathology. This thesis describes two quantitative studies into the role and relevance of various causative factors in the development of negative body image in cohorts of volunteers drawn from the general population of the University of Bradford in West Yorkshire, UK. In Study One, subjects (n=360) completed a self-directed questionnaire that psychometrically measured satisfaction/dissatisfaction with personal appearance, queried which external sources influenced those opinions, and correlated these with demographic information. In particular, we sought to examine how a subject¿s opinion about their personal appearance varied with age, gender, ethnicity, mental health, relationship status, sexual orientation and Body Mass Index (BMI). Subjective views regarding personal appearance were determined by answers given to specific body image questions that revealed a subject¿s day-to-day appearance concerns, all preoccupations, and the extent to which these concerns resulted in distress, all social impairment. Overall, the results demonstrated that BMI values were positively correlated with personal appearance concerns. High BMI values correlated with greater dissatisfaction with personal appearance. Self ratings of appearance values were negatively correlated with BMI scores. Subjects who gave themselves high appearance ratings were relatively unaffected by media influence with regard to their image, compared to subjects rating themselves less attractive. These latter subjects also showed higher peer pressure scores in terms of both the amount of time they compared themselves to peers, and the degree to which peer comparisons affected their self-appearance ratings. Based on responses to the body image questions specifically, the entire cohort of subjects were categorised into principal clusters: those largely unaffected by any body image concerns; and those profoundly distressed by their self assessed body image. Perhaps the most interesting aspect of these findings is that the scores for this latter (n=17) group of subjects on the body image questions revealed a degree of personal distress this is almost identical to the scores expected from those people diagnosed with body dysmorphic disorder (BDD). Collectively, these results suggest that high BMI values in subjects negatively impact on self-appearance ratings, render subjects more prone to media messages that portray body image ideals, and elicit frequent comparisons with peers to validate self-image concerns. Furthermore, severely affected subjects with high BMI scores may show similar psychopathology to that of BDD sufferers. In Study Two, a small cohort of subjects (n=60) were given questionnaires and were interviewed to further investigate self-appearance ratings and mood/depressive traits. The body image questions used in Study One to assess image concerns and the magnitude of distress were repeated in Study Two. Mood and depressive state were measured using the validated Beck¿s Depression Inventory (BDI). In parallel, subjects completed the Derriford Appearance Scale 59 (DAS 59), which is a valid psychometric indication of an individual's perception of their appearance as ¿normal¿ or ¿disfigured¿, and used as a tool by plastic surgeons to inform decisions regarding the necessity for surgery to correct an individual's appearance. Physiological markers were recorded before and after exposure of subjects to a physical and a psychological stressor: these were saliva concentrations of cortisol and sIgA (an immune marker), blood glucose and blood pressure. The results of Study Two revealed no changes in scores for any of the physiological measures following stressors. BDI scores for most subjects fell within normal ranges, although females scored higher than males, but not at a pathological level. Those subjects with a history of mental illness or those who reported feeling a high degree of stress on a daily basis, or those who expressed greater self-appearance concerns, all had significantly elevated BDI values. Perhaps the most intriguing finding from Study Two, as in Study One, was that subjects again tended to fall within specific categories for body image concerns: those unaffected or minimally affected by body image concerns, and those (n=6) greatly and deleteriously affected by body image concerns. This subsection of subjects also scored very high on the DAS 59 for disfigurement. On the basis of these findings it would seem that body image concerns may be severe enough for some individuals for them to perceive themselves as actually being disfigured, or that the DAS 59 (a widely used assessment tool in plastic surgery), may not be entirely appropriate for assessment of an individual's need for surgery because it cannot distinguish between those genuinely disfigured and those merely expressing severe body image concerns.

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<p><strong>Objectives: </strong>To examine associations between macrosomia, maternal body mass index (BMI) during pregnancy, and psychopathology in youth, and to determine if these are due to prenatal environmental exposures or confounding variables.</p> <p><strong>Methods: </strong>Study 1 reviewed studies examining associations between macrosomia and mental health. Data from the Ontario Child Health Study (OCHS) were then used to explore these links in youth (Study 2). A second review summarized studies assessing associations between maternal pregnancy BMI and psychopathology in offspring (Study 3). Data from the Western Australia Pregnancy Cohort were then used to quantify associations between maternal pre-pregnancy BMI and child behaviour at age 1 and 2 (Study 4), and from 5-17 years of age (Study 5).</p> <p><strong>Results: </strong>Seven of the 15 studies that had examined associations between macrosomia and psychopathology supported a link. In the OCHS, youth born macrosomic had elevated externalizing scores compared those born at appropriate birth weights. Eight of 12 studies suggested that links exist between elevated maternal BMI during pregnancy and psychopathology in offspring. Maternal pre-pregnancy BMI was positively associated with offspring externalizing problems from age 2 to 17 and linked to less favourable trajectories of internalizing symptoms from 5-17. These findings persisted despite adjustment for confounders.</p> <p><strong>Conclusions: </strong>Youth born macrosomic have elevated levels of externalizing symptoms, though a more robust association was noted with maternal pre-pregnancy BMI. The data comprising this thesis suggest that associations between macrosomia/maternal BMI and externalizing and internalizing problems in youth may be due to intrauterine exposures rather than confounding variables.</p> / Doctor of Philosophy (PhD)

<p>Background: The objective of this thesis was to examine the role of psychosocial factors in weight loss success after bariatric surgery. It was proposed that a higher pre-operative body mass index (BMI), greater weight, depression, low self-esteem, and a childhood history of sexual abuse (CSA) would predict poor outcomes one year after Roux-en-y gastric bypass as evidenced by a BMI > 35 kg/m²and a lower percent total weight loss (%TWL). Methods: We administered a battery of psychological screening tools, including the Beck Depression Inventory-II, the Rosenberg Self-Esteem Scale and a self-report measure assessing CSA, to 262 patients seeking bariatric surgery at St. Joseph's Healthcare Hamilton. Patients completed the questionnaires prior to surgery and again one year post-surgery. Results: On average patients (n = 79) achieved good weight loss outcomes (BMI = 32.8 kg/m²) at one-year follow-up. Through multiple regression analysis we found that pre-operative BMI accounted for a significant proportion of variance in postoperative BMI [<em>R²</em> = .60, <em>F</em>(1, 77) = 114.4, <em>p</em> < .001]. Weight before surgery, however, did not predict %TWL after surgery. None of the psychosocial variables significantly predicted post-operative BMI or weight loss. These results are preliminary and are limited by the fact that participants did not present with clinically significant symptomatology and those with active psychopathology were excluded as suitable surgical candidates. Conclusion: These findings indicate that pre-operative BMI is a significant predictor of BMI one year after bariatric surgery, suggesting that more attention should be directed toward managing pre-operative BMI for heavier patients.</p> / Master of Science (MSc)

Background: Obesity has been associated with increased health care use, but it is unclear whether this is consistent across all measures of obesity. The objectives of this thesis were to compare obesity defined by four anthropometric measures, body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and percent body fat (%BF), and to estimate their associations with health care use among Canadian adults. Methods: A secondary data analysis was conducted from 30,097 individuals aged 45-85 years from the Canadian Longitudinal Study on Aging. Anthropometric measures were collected by trained research assistants and %BF, the reference standard, was measured using dual-energy x-ray absorptiometry. Obesity was defined as BMI≥30.0 kg/m2, WC≥88cm for females and ≥102cm for males, WHR≥0.85 for females and ≥0.90 for males, and %BF>35% for females and >25% for males. Approximately 18 months after baseline data collection, self-reported health care use in the past 12 months was collected, including any contact with a general practitioner, medical specialist, emergency department, and being a patient in a hospital overnight. Pearson correlation coefficients and sensitivity and specificity analyses were conducted to compare anthropometric measures to %BF. Relative risks and risk differences were calculated for measures of health care use, adjusted for sex, age, education, income, urban/rural, marital status, smoking status, and alcohol use. Secondary analyses were also stratified by sex and age. Results: The prevalence of obesity defined by BMI was 29%, by WC was 42%, by WHR was 62%, and by %BF was 73%. BMI and WC were highly correlated with %BF (r=0.75 and r=0.70, respectively) and WHR was weakly correlated with %BF (r=0.29). BMI and WC cut points demonstrated high specificity (>93%) and lower sensitivity (<58%) in predicting obesity defined by %BF. WHR cut points demonstrated high sensitivity (95%) and lower specificity (28%) in males, but lower sensitivity (44%) and high specificity (83%) in females in predicting %BF- defined obesity. There was an increased relative and absolute risk of health care use for all measures of obesity and all health care services. For example, WC-defined obesity was associated with increased relative risk (RR) of hospital overnight stay (RR: 1.40, 95% CI: 1.28- 1.54) and the risk difference (per 100) was 2.6 (95% CI:1.9-3.3). The risk of health care use was similar amongst females and males with obesity although relative risks and risk differences attenuated in the oldest adult group aged 75 and older compared to the youngest group aged 45- 54. Conclusion: The prevalence of obesity among Canadian adults varied substantially by anthropometric measure. BMI and WC have stronger correlations and concordance with %BF than does WHR, however all measures were positively associated with increased health care use. Further research should be conducted on obesity cut points to discern the best measure to predict health care use. / Thesis / Master of Public Health (MPH)

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No description available.

The nature of food insecurity has been changing in the world. While research on food insecurity in developing countries used to focus on undernourishment (i.e. lack of calorie consumption) and related outcomes, today, many developing countries face at least a “double burden of malnutrition” with persistently high rates of undernourishment and increasing rates of overweight, obesity and related non-communicable diseases (NCDs). An important driver of overweight and obesity in developing countries is the „nutrition transition“, i.e. the trend towards the consumption of more energy-dense, highly processed foods and more sedentary lifestyles. Two essays of this Ph.D. thesis analyse drivers and consequences of the nutrition transition in developing countries with a particular focus on the role of supermarkets, which have been rapidly spreading in many countries. We provide evidence that the presence of supermarkets causally affects dietary choices and nutritional outcomes. Data collection for this research was carried out in small Kenyan towns of the kind that accommodate most of the country’s urban population. We designed our sample to be quasi-experimental in nature and employ instrumental variable techniques to allow for endogeneity of supermarket purchases. Kenya’s supermarket landscape is dynamic and so far, it has followed the ‘traditional pattern’ of the so-called supermarket revolution. Supermarket purchases are found to contribute to the nutrition transition by shifting consumption towards processed and away from unprocessed foods. At the same time, calorie availability increases as calories are sourced at lower prices in supermarkets. We find that supermarket purchases increase adult Body Mass Index and their probability of being overweight or obese. Yet, we also find that buying in a supermarket tends to decrease underweight among children and adolescents (age 5-19) in terms of stunting (height-for-age). In a third essay, we use secondary household survey data from Malawi to analyse ‘one of the other faces of malnutrition’. The world food price crisis of 2007/08 and other global and regional price and income shocks that followed have spurred interest in producing timely predictions on their implications for food security. A critical research gap remains with comparing simulation outcomes across studies that use different, established methods on the same subject. This is to establish if and to which extent they might result in different and potentially conflicting policy recommendations. We address this gap building on three simulation studies set in Malawi, which analyse welfare in terms of food security and income effects using the same 2004/05 household survey data but resort to methodologies of different complexity. We harmonize simulation scenarios across methods and systematically modify relevant parameters for our comparative assessment. We find differences between methods to depend on the scenario under consideration and to grow with increasing rates of simulated price changes. The differences we find are driven by differences in conceptualising price changes. In case of Malawi, for a reasonable set of observed price changes, mean outcomes on district levels are fairly robust to underlying methodologies. We illustrate that is it important to improve our understanding of how changes in the underlying methodologies change results and to analyse the sensitivity of simulation outcomes to different model assumptions.

Obesity has been related to a greater incidence of more aggressive, advanced stage prostate cancer. It is expected that serum adipokines related to obesity will promote a more aggressive phenotype in PC cells in vitro. Patient serum (n = 80) was obtained for analysis and divided into four patient groups based on obesity and prostate cancer status. Characteristics of serum-treated PC cells in vitro were measured. In a separate set of analyses, LNCaP and PC3 cells were treated with adiponectin and resistin in vitro, and cell characteristics were analyzed. Serum from obese PC patients induces greater amounts of cell migration and lower amounts of cell proliferation and invasion in vitro. Exogenous treatment of adiponectin on PC cells in vitro does not affect cell migration or invasion. However, adiponectin modulates cytosolic protein levels of soluble β-catenin and GSK-3β, indicating that its mechanism of action may be through the Wnt signalling pathway.

Objectives: To examine variation in clustered metabolic risk (cMetS) in adolescents classified as not overweight/active (NOA), not overweight/not active (NONA), overweight/active (OA), and overweight/not active (ONA). Background: While studies to date have shown that children and adolescents who meet the current physical activity (PA) recommendations and maintain a healthy body weight demonstrate significantly lower cardiometabolic risk, there are some studies that suggest the relationship between PA and metabolic risk may be mediated by adiposity. Methods: The sample included adolescent participants (n=875; 12-17 years) of the 2007-2012 National Health and Nutrition Examination Survey (NHANES). The cMetS score included triglycerides, high-density lipoprotein cholesterol, fasting plasma glucose, and mean arterial pressure. Age- and sex-specific body mass index (BMI) percentiles were utilized; overweight was defined as BMI percentile ≥ 85th. Activity data included self-reported frequency of moderate-to-vigorous PA. Adolescents reporting ≥ 60 min/day of PA were considered “active”. General linear models, adjusted for age, sex, and race-ethnicity, were used. A six-year fasting sample weight was applied to the analyses in order to ensure representativeness of the data. Results: The cMetS scores were significantly (p Conclusions: The cMetS scores were higher in OA and ONA adolescents when compared to those classified as NOA. Whereas only ONA males demonstrated significantly higher cMetS score when compared to the NOA referent, both OA and ONA cMetS scores (vs NOA) were significantly higher in females.