Thesis (Ph. D.)--Uniformed Services University of the Health Sciences, 2005. / Includes bibliographical references (p. 84-103). Also available via the Internet.

Relatively few studies have examined the effects of psychostimulants in obese subjects. Using the dietary obese rat model, the present experiments determined the reductions in food intake (hypophagia) and increases in locomotion (hyperlocomotion) induced by cocaine in diet-induced obese prone (DIO-prone) rats and diet resistant prone (DR-prone) rats as well as diet-induced obese (DIO) rats and diet resistant (DR) rats. In Experiment 1, thirty-six male Sprague-Dawley rats were given intra-peritoneal (i.p.) injections of cocaine (0, 10, 20, and 30 mg/kg) immediately prior to placement into locomotor chambers outfitted with a food source and a water source for a 60-minute test period. In Experiment 2, the same rats were exposed to a high-fat diet, and were subsequently divided into groups according to the extent of the weight gain (high weight gainers œ DIO group, low weight gainers œ DR group, and residual weight gainers œ MIX group). The rats were retested for reactivity to cocaine using conditions similar to those in Experiment 1. Rats injected with cocaine prior to high-fat exposure (Experiment 1) showed a dose dependent suppression of food intake, as well as a dose dependent increase in locomotor activity, with DR-prone rats exhibiting an enhanced degree of cocaine-induced hypophagia, as well as cocaine-induced hyperlocomotion as compared to the other groups. In Experiment 2, DIO rats exhibited a suppression of food intake after injection of 10 mg/kg cocaine, as well as an increase in locomotor activity that was significantly greater than noted in the other groups. When the results of Experiment 1 were analyzed as a function of prospective body weight gain (as opposed to placement into distinct groups), reactivity to cocaine decreased as body weight gain increased. In contrast, after high-fat exposure and weight gain, increased body weight gain was associated with an increased magnitude of suppression in food intake after cocaine administration. Similar patterns of differential cocaine sensitivity were observed for cocaine hyperlocomotion in Experiment 2. These studies indicate that although the propensity to develop obesity is associated with a diminished cocaine response, cocaine reactivity is enhanced after the induction of obesity.

The present study explored the influence of survivor weight and participant gender, rape myth acceptance and anti-fat attitudes on perceptions of sexual assault. Using an online survey tool, participants (N = 413) read a vignette describing a hypothetical sexual assault scenario and completed several self-report questionnaires. Generalized linear model analyses revealed that participants were more likely to hold the survivor responsible, excuse the perpetrator’s actions, and respond more negatively toward the survivor and more positively toward the perpetrator when the survivor was depicted as thin versus overweight. Interactions were found between rape myth acceptance and survivor weight, gender and survivor weight, and gender and anti-fat attitudes, for certain dependent variables. In addition, men and those with higher levels of rape myth acceptance and anti-fat attitudes were found to make more negative evaluations of the survivor and more positive evaluations of the perpetrator. Recommendations for future research and interventions are discussed.

Urban Aboriginal youth are one of the fastest growing populations in Canada (Statistics Canada, 2008). There is growing concern with the increasing rate of overweight and obesity among Aboriginal youth (Reading, 2009). Although this unique group is quickly growing, and possibly experiencing more ill health than non-Aboriginal youth their voices are currently absent in Aboriginal health literature. Drawing on the voices of urban Aboriginal youth to understand their perspectives is important for the promotion and enhancement of overall health (RCAP, 1996). One specific topic absent from the literature is the influence of culture on body weight, physical activity, and diet for urban Aboriginal youth. (Gittelsohn et al., 1996; Kumanyika, 1993; Marchessault, 1999; Thompson, Gifford, & Thorpe, 2000; Willows, 2005). Culture is seen as the beliefs, behaviours, norms, attitudes, and social arrangements that form patterns in the lives of members (LeCompte & Shensul, 1999, pg 21). The purpose of this study was to examine the influence of culture on body weight, physical activity, and diet for urban Aboriginal youth.<p> This study used the qualitative methodology of focused ethnography. The study setting was an urban Aboriginal high school in Saskatoon, Saskatchewan, Canada. Fifteen participants (11 females, 4 males) took part in this study. Participants were between the ages of 14-21, with a mean age of 16.73. Methods of data collection included semi-structured interviews, informal conversations, talking circles, and participant observation. The researcher spent 10-15 hours a week for eight months on site in the research setting.<p> In this study four themes describe the influence of culture on body weight, diet, and physical activity. These themes were: (i) acceptance of our bodies, (ii) playing together, past and present, (iii) traditions and sharing, and (iv) the struggle. The young urban Aboriginal participants in this study believed that a healthy body weight comes in a variety of sizes. There was a general acceptance in the diversity of healthy body weights and sizes. Group physical activity and competitive activity was favoured among participants. Traditional physical activities such as dancing, hunting, and fishing were cited as important by all participants. Participants believed traditional foods to be healthy and desirable, and those who reported eating traditional foods less frequently desired to eat them more often. Food sharing networks consisting of friends and family were reported as a way to address food insecurity and acquire traditional foods from the participants home reserves. In this study barriers to physical activity and diet for urban Aboriginal youth were income, location or residence, and transportation. Participants attempted to overcome them when it was possible, which highlights a resiliency among urban Aboriginal youth.<p> In conclusion, this study offers valuable information on the influence of culture on body weight, physical activity, and diet for urban Aboriginal youth. Participants in this study engaged in a variety of traditional and cultural activities. These activities increased the healthy eating habits and physical activity levels of the participants. Thus, cultural engagement may be a health enhancing mechanism for urban Aboriginal youth in Canada.

The present study explored the influence of survivor weight and participant gender, rape myth acceptance and anti-fat attitudes on perceptions of sexual assault. Using an online survey tool, participants (N = 413) read a vignette describing a hypothetical sexual assault scenario and completed several self-report questionnaires. Generalized linear model analyses revealed that participants were more likely to hold the survivor responsible, excuse the perpetrator’s actions, and respond more negatively toward the survivor and more positively toward the perpetrator when the survivor was depicted as thin versus overweight. Interactions were found between rape myth acceptance and survivor weight, gender and survivor weight, and gender and anti-fat attitudes, for certain dependent variables. In addition, men and those with higher levels of rape myth acceptance and anti-fat attitudes were found to make more negative evaluations of the survivor and more positive evaluations of the perpetrator. Recommendations for future research and interventions are discussed.

Urban Aboriginal youth are one of the fastest growing populations in Canada (Statistics Canada, 2008). There is growing concern with the increasing rate of overweight and obesity among Aboriginal youth (Reading, 2009). Although this unique group is quickly growing, and possibly experiencing more ill health than non-Aboriginal youth their voices are currently absent in Aboriginal health literature. Drawing on the voices of urban Aboriginal youth to understand their perspectives is important for the promotion and enhancement of overall health (RCAP, 1996). One specific topic absent from the literature is the influence of culture on body weight, physical activity, and diet for urban Aboriginal youth. (Gittelsohn et al., 1996; Kumanyika, 1993; Marchessault, 1999; Thompson, Gifford, & Thorpe, 2000; Willows, 2005). Culture is seen as the beliefs, behaviours, norms, attitudes, and social arrangements that form patterns in the lives of members (LeCompte & Shensul, 1999, pg 21). The purpose of this study was to examine the influence of culture on body weight, physical activity, and diet for urban Aboriginal youth.<p> This study used the qualitative methodology of focused ethnography. The study setting was an urban Aboriginal high school in Saskatoon, Saskatchewan, Canada. Fifteen participants (11 females, 4 males) took part in this study. Participants were between the ages of 14-21, with a mean age of 16.73. Methods of data collection included semi-structured interviews, informal conversations, talking circles, and participant observation. The researcher spent 10-15 hours a week for eight months on site in the research setting.<p> In this study four themes describe the influence of culture on body weight, diet, and physical activity. These themes were: (i) acceptance of our bodies, (ii) playing together, past and present, (iii) traditions and sharing, and (iv) the struggle. The young urban Aboriginal participants in this study believed that a healthy body weight comes in a variety of sizes. There was a general acceptance in the diversity of healthy body weights and sizes. Group physical activity and competitive activity was favoured among participants. Traditional physical activities such as dancing, hunting, and fishing were cited as important by all participants. Participants believed traditional foods to be healthy and desirable, and those who reported eating traditional foods less frequently desired to eat them more often. Food sharing networks consisting of friends and family were reported as a way to address food insecurity and acquire traditional foods from the participants home reserves. In this study barriers to physical activity and diet for urban Aboriginal youth were income, location or residence, and transportation. Participants attempted to overcome them when it was possible, which highlights a resiliency among urban Aboriginal youth.<p> In conclusion, this study offers valuable information on the influence of culture on body weight, physical activity, and diet for urban Aboriginal youth. Participants in this study engaged in a variety of traditional and cultural activities. These activities increased the healthy eating habits and physical activity levels of the participants. Thus, cultural engagement may be a health enhancing mechanism for urban Aboriginal youth in Canada.

Relatively few studies have examined the effects of psychostimulants in obese subjects. Using the dietary obese rat model, the present experiments determined the reductions in food intake (hypophagia) and increases in locomotion (hyperlocomotion) induced by cocaine in diet-induced obese prone (DIO-prone) rats and diet resistant prone (DR-prone) rats as well as diet-induced obese (DIO) rats and diet resistant (DR) rats. In Experiment 1, thirty-six male Sprague-Dawley rats were given intra-peritoneal (i.p.) injections of cocaine (0, 10, 20, and 30 mg/kg) immediately prior to placement into locomotor chambers outfitted with a food source and a water source for a 60-minute test period. In Experiment 2, the same rats were exposed to a high-fat diet, and were subsequently divided into groups according to the extent of the weight gain (high weight gainers œ DIO group, low weight gainers œ DR group, and residual weight gainers œ MIX group). The rats were retested for reactivity to cocaine using conditions similar to those in Experiment 1. Rats injected with cocaine prior to high-fat exposure (Experiment 1) showed a dose dependent suppression of food intake, as well as a dose dependent increase in locomotor activity, with DR-prone rats exhibiting an enhanced degree of cocaine-induced hypophagia, as well as cocaine-induced hyperlocomotion as compared to the other groups. In Experiment 2, DIO rats exhibited a suppression of food intake after injection of 10 mg/kg cocaine, as well as an increase in locomotor activity that was significantly greater than noted in the other groups. When the results of Experiment 1 were analyzed as a function of prospective body weight gain (as opposed to placement into distinct groups), reactivity to cocaine decreased as body weight gain increased. In contrast, after high-fat exposure and weight gain, increased body weight gain was associated with an increased magnitude of suppression in food intake after cocaine administration. Similar patterns of differential cocaine sensitivity were observed for cocaine hyperlocomotion in Experiment 2. These studies indicate that although the propensity to develop obesity is associated with a diminished cocaine response, cocaine reactivity is enhanced after the induction of obesity.

Thesis (Ph.D.)--Kent State University, 2008. / Title from PDF t.p. (viewed Nov. 2, 2009). Advisor: Kristin Mickelson. Keywords: social support; stigma; controllability. Includes bibliographical references (p. 74-88).

Background: With adolescent obesity increasing in many developed and developing countries, many studies have investigated the effects of dietary habits on adolescent obesity. However, night-eating, which may lead to extra caloric intake and weight gain, is understudied. Given adolescents’ behavior patterns required during this period to be likely to influence long term behaviors, the present study investigated the prevalence of night-eating in Hong Kong adolescents and its association with weight status, dinner habits, bedtime, and the interval between dinner time and bedtime. Methods: This study was a secondary analysis with a sample of 24885 adolescents based on the dataset of Hong Kong Student Surveillance (HKSOS) project which was a school-based cross-sectional survey conducted in 2006/07. The subjects reported the number of days they had night-eating per week, the usual time they had dinner, the time spent on dinner, and bedtime. The interval between dinner time and bedtime was calculated and classified as long (4 hours or more) or short (below 4 hours). Weight status was estimated based on the self-reported weight and height. The prevalence of night-eating and distributions of dinner habits and bedtime were examined using descriptive statistics (mean, standard deviation and percentage). Logistic regression and multiple linear regression models with robust standard errors accounting for school clustering effects were used (Stata 11.0) to estimate crude and adjusted odds ratios (OR) and regression coefficients for associations about night-eating. Results: Half (50.2%) the subjects reported any night-eating and 21.9% reported frequent night-eating of more than three days a week. The change of BMI z-score was positive associated with night-eating (Coefficient: 0.204; 95%CI: 0.175-0.233), and night-eaters were 13% (95%CI: 6%-20%) more likely to be obese. Compared with early dinner time group, the normal dinner time group was 11% (95% CI: 6%-15%) less likely to have night-eating. Students who reported normal and slow eating speed were 30% (95 % CI: 22%-39%) and 147% (95% CI: 113%-187%) more likely to have night-eating compared with quick eating speed group; the late-sleepers were 43% (95% CI: 35%--53%) and 25% (95%CI: 18%--34%) more likely to have night-eating on weekday and weekend, respectively, compared with early-sleepers. Besides, it was observed that adolescents having longer interval between dinner time and bedtime were 22% (95% CI: 5%--42%) more likely to have night-eating. Conclusion: The prevalence of night-eating was 50.2% in Hong Kong students. The night-eating was positively related with obesity, and the relationship was the first time to be estimated in Hong Kong adolescents. Besides, the relative early dinner time (compared with bedtime), slow dinner speed, late bedtime and long interval between dinner time and bedtime were positively associated with night-eating. / published_or_final_version / Public Health / Master / Master of Public Health

Background: As modern nations undergo demographical and epidemiological transitions, infectious diseases are replaced by non-communicable and chronic illnesses as the main source of ill-health. In particular, the obesity epidemic is of important public health concern as the prevalence of overweight and obesity continues to increase at an alarming rate globally. The trend in childhood and adolescent obesity is also escalating rapidly as people are gaining excess weight at younger ages, representing a growing threat as obesity is linked to a myriad of detrimental psychosocial and physical health consequences which may persist through adulthood. The fundamental cause of obesity is energy imbalance with energy intake exceeding energy expenditure within the human body. Total daily energy expenditures can vary substantially among individuals due to non-exercise activity thermogenesis (NEAT), which accounts for the energy expended from activities we do in daily living, including spontaneous behaviours such as fidgeting. Cumulatively, trivial activities such as fidgeting may accrue to have a significant impact on total daily energy expenditure. Studies have shown that NEAT levels increase or decrease in response to over- and under-feeding, respectively, to counterbalance changes in energy homeostasis. Therefore, fidgeting and NEAT may be an important component in maintaining weight. Decreased levels of fidgeting and NEAT has been hypothesized to be more common among obese individuals as the body fails to activate NEAT in response to over-eating, leading to weight gain. Understanding the correlates of fidgeting and non-exercise physical activity will be helpful in supplementing the design and implementation of effective strategies against obesity. Objective: To investigate the correlates of fidgeting among Hong Kong adolescents, including the association between fidgeting and weight status. Methods: Post hoc statistical analysis was conducted using secondary data from the Hong Kong Student Obesity Surveillance (HKSOS) Project from 2006-2007, which surveyed 34 678 students across 42 secondary schools in Hong Kong. Multivariate logistic regression analyses yielded crude and adjusted odds ratios for the associations of background characteristics, lifestyle characteristics, and dietary intake on fidgeting. Multinomial logistic regression analyses estimated crude and adjusted odds ratios to evaluate the associations between weight status and fidgeting/non-exercise physical activity. Results: Among the sample of Hong Kong adolescents, subjects who were male, older, born outside of Hong Kong, and had daily consumption of fresh fruits, fresh vegetables, and protein were associated with having lower odds of fidgeting. In contrast, high paternal control, high maternal control, smoking, alcohol consumption, elevated levels of daily screen time, exercise time, non-exercise physical activity time, and increased intake in deep fried/fatty foods, snacks/fizzy drinks, coffee, and tea were all associated with having higher odds of fidgeting. Fidgeting did not appear to have any significant relationships with weight status. However, non-exercise physical activity was associated with increased odds of being both underweight and overweight. Conclusions: The results from this study indicate that there are meaningful associations between fidgeting and various correlates, including background demographic characteristics and modifiable behavioural factors. Further studies are required to gain a better understanding of the correlates of fidgeting and their implications to public health. / published_or_final_version / Public Health / Master / Master of Public Health