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Body weight in mammals is defended so that small changes in weight evoke neuroendocrine and metabolic responses that encourage a return to one’s previous weight. While these homeostatic responses have been more commonly studied in the case of weight loss, our lab has developed a mouse model of overfeeding to study the physiology of defense against weight gain. In response to overfeeding-induced weight gain, the return to previous body weight is mediated primarily by a striking reduction in food intake, which persists until pre-overfeeding body weight is restored. However, preliminary data do not suggest activation of anorectic POMC neurons which reduce food intake or inhibition of the appetite stimulating AgRP or NPY neurons in the arcuate nucleus of the hypothalamus. Furthermore, we found that adipose tissue from overfed mice does not show the same inflammatory response as mice that have become obese slowly due to ad libitum high-fat diet (HFD) consumption. Paradoxically, despite the existence of mammalian systems that defend against weight gain, average body weight in humans has been on the rise over the last half century. Concomitant with the rise in obesity rates, has been increasing availability and consumption of processed and fast foods which are generally high in sugar, salt, and fat making them extremely palatable and calorically dense. Both the caloric density and enticing taste of the foods have been implicated in causing overconsumption and contributing to a rise in average body weight and prevalence of obesity. Thus, while controlling for caloric density we have investigated whether diet palatability can increase body weight and suppress defense against weight gain in mice. We designed our studies so that all diets were of the same caloric density and therefore varied only proportion of calories derived from fats, carbohydrates, and protein. Palatability is the relative subjective preference of one food over another; in our mouse studies we equated preference, when given, a choice with palatability. We confirmed that liquid diets sweetened with sucrose or the non-nutritive sweeteners sucralose and saccharin were preferred over non-sweetened diets. In 12 day feeding studies, although we found that sweetened diets were more palatable than unsweetened diets, they did not increase caloric intake or body weight. Next, we tested whether increasing percent calories from fat leads to increases in palatability or caloric intake. In a similar 12 day feeding preference study, we found diets higher in percent calories from fat (high-fat diet = HFD) were preferred to diets with lower percent calories from fat (low-fat diet = LFD) and that the access to a HFD increased caloric intake and body weight. Employing a four-week single diet feeding study, we also found a linear relationship between percent calories from fat and caloric intake consistent with our hypothesis that percent calories from fat is sensed and modulates caloric intake. To test whether HFD can suppress defense of body weight, we used an overfeeding paradigm which I help develop, to test whether ad libitum access to a HFD prevented a return to the original body weight following overfeeding. HFD did attenuate the hypophagic response to overfeeding and prevented a return to each mouse’s initial weight with the mice having access to the HFD mice stabilizing at a higher body weight. Palatability has traditionally been ascribed to sensing of smell and taste, however, macronutrients can also be sensed within intestinal tract. To determine whether the effects of percent calories from fat require naso-oral sensing to modulate feeding behavior, we used an intragastric feeding system to bypass taste and smell and deliver HFD directly into the stomach of mice. Even in the absence of oropharyngeal sensing, HFD in the gut was sufficient to increase ad libitum caloric intake of a low-fat diet and increase body weight. Finally, based on our findings of post-oral fat sensing driving caloric intake, we tested whether post-oral sensing of percent calories from fat was sufficient to condition a flavor preference. However, we found that when caloric density was controlled, a high percent calories from fat was not sufficient to condition a flavor preference.

Type 2 diabetes is a highly prevalent disease, projected to increase in prevalence, while expensive to treat. This study sought to identify significant predictors of each of the two study outcome variables—a higher quality of patient-provider communication, and a higher quality of life. The online sample (N=72) was 78% (n=56) female with a mean age of 55.3 years, while 71% Black/African American with a good overall health status. They rated the overall quality of care received from their provider between good and very good. Using the new Patient-Provider Communication Scale (PP-CS-07, patient-provider communication was closest to very good. Health literacy skills were closest to very good, and health literacy self-efficacy was closest to very good. Level of knowledge for caring for type 2 diabetes was closest to very good knowledge. Participants were in an action stage with 80% confidence (very good self-efficacy) to perform seven diabetes self-management behaviors. Some 43.1% experienced depression, 44.4% experienced anxiety, and 20.8% sought counseling in the past year. The mean quality of life rating was closest to good quality of life. While controlling for social desirability, backward stepwise regression showed better quality patient-provider communication was significantly predicted by: received diabetes education, higher rating of health care quality, higher level of health literacy skills, and, being in a lower stage of change for self-care behaviors—with 79.2% of variance explained by this model. Better quality of life was significantly predicted by: female gender, having received diabetes education, no past year anxiety, higher annual household income, lower weight status, higher health literacy self-efficacy, higher rating of knowledge of diabetes self-management—with 69.4% of the variance explained by this model. Findings make a compelling case for screening patients for depression and anxiety, using the brief tool used in this study; and future research evaluating the impact of health educators and providers being trained in motivational interviewing, while using the Patient-Provider Communication Scale (PP-CS-7) as a new tool to compare ratings by patients of providers trained in motivational interviewing. Healthcare policy should mandate such training in brief motivational interviewing, and evaluate the impact of training in containing costs.

Lo Wing-sze. / One booklet (14 p. : col. ill. ; 21 cm.) mounted on leaf 156. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 100-113). / Abstracts in English and Chinese; questionnaires also in Chinese. / Acknowledgements --- p.ii / Abstract --- p.iii / Abstract (Chinese Version) --- p.v / Publications / Table of Contents --- p.viii / List of Figures --- p.xiii / List of Tables --- p.xv / List of Abbreviations --- p.xviii / Chapter Chapter One: --- Introduction / Chapter 1.1 --- Childhood obesity trends and measurement in Hong Kong and Elsewhere in the recent decade --- p.1 / Chapter 1.2 --- Health consequences of childhood obesity --- p.3 / Chapter 1.3 --- Determinants of childhood obesity --- p.4 / Physical inactivity --- p.4 / High-fat diet --- p.5 / Chapter 1.4 --- Parental eating attitudes on family food environments --- p.6 / Home food purchasing and availability --- p.6 / Family meal frequency and location --- p.7 / Child feeding practices- the food and eating rules --- p.8 / Chapter 1.5 --- The relationship of socioeconomic status and obesity --- p.8 / The economic status of households in Hong Kong --- p.10 / Chapter 1.6 --- Targeting children aged three and four years --- p.12 / Chapter 1.7 --- Conceptual framework and study objectives --- p.13 / Chapter Chapter Two: --- Survey Design / Chapter 2.1 --- Sample design and subject recruitment --- p.15 / Chapter 2.2 --- Survey methods --- p.17 / Anthropometric measurement --- p.17 / Lifestyle questionnaire --- p.18 / Three-day 24-hour dietary intake recall --- p.20 / Chapter 2.3 --- Data management and analysis methods --- p.23 / Anthropometric measurements --- p.23 / Lifestyle questionnaire --- p.24 / Three-day 24-hour dietary intake recall --- p.24 / Socioeconomic status (SES) of the subjects (Households) --- p.25 / Chapter 2.4 --- Ethics --- p.25 / Chapter Chapter Three: --- Results / Chapter 3.1 --- Responses to various components of the survey --- p.26 / Chapter 3.2 --- Socioeconomic status and related characteristics of the households --- p.28 / Chapter 3.3 --- Characteristics of the preschooler and their carers --- p.34 / Preschooler s weight status --- p.34 / Preschooler s growth --- p.35 / Other characteristicsof the preschoolers --- p.37 / Chapter 3.4 --- Home food purchasing and its determinants --- p.40 / Chapter 3.5 --- Family meal frequency and location --- p.43 / Chapter 3.6 --- Preschoolers' meal preparation activities --- p.48 / Chapter 3.7 --- Food and eating rules and mealtime activities --- p.50 / Chapter 3.8 --- Child's sedentary activities patterns and parental perceptions --- p.53 / Chapter 3.9 --- "Parental perceptions of preschooler's height and weight, and eating habits" --- p.57 / Chapter 3.10 --- Nutrient intakes of the preschoolers --- p.59 / Chapter 3.11 --- Food consumption patterns of the preschoolers --- p.63 / Chapter 3.12 --- Meal and snack patterns of the preschoolers --- p.67 / Chapter 3.13 --- Main contribution of food sub-groups to energy and various nutrient intakes for preschoolers --- p.69 / Chapter 3.14 --- Intakes of energy and various nutrients from foods eaten at home and outside home --- p.72 / Chapter 3.15 --- "Associations of parental feeding practices, preschoolers' nutrient intakes and physical activity patterns with childhood overweight and obesity" --- p.75 / Parental feeding practices and attitudes toward healthy eating by preschoolers'weight status --- p.75 / Activity patterns of the preschoolers by weight status --- p.76 / Energy and various nutrient intakes of the preschoolers by weight status --- p.77 / Chapter Chapter Four: --- Discussion / Chapter 4.1 --- Childhood obesity rate by SES group --- p.80 / Chapter 4.2 --- Characteristics of the preschoolers and the households --- p.81 / Chapter 4.3 --- High SES families dined together less frequently than their low SES counterparts --- p.84 / Chapter 4.4 --- Preferences of family members as an influential factor in purchasing fruits and vegetables --- p.86 / Chapter 4.5 --- Encouraging healthy food shopping practices with the preschoolers --- p.87 / Chapter 4.6 --- Food and eating rules imposed by parents may influence preschooler's eating habits and nutrient intakes --- p.88 / Chapter 4.7 --- Preschooler's sedentary activities patterns --- p.89 / Chapter 4.8 --- Incorrect parental perceptions of preschooler's weight --- p.91 / Chapter 4.9 --- Nutrient intakes of the preschoolers overall --- p.91 / Chapter 4.10 --- Comparing the nutrient intakes of the preschoolers with another study carried out in 2000 --- p.93 / Chapter 4.11 --- Parental/preschooler association on fruit and vegetable consumption --- p.94 / Chapter 4.12 --- Main contributors of food sub-groups to energy and various nutrient intakes for the preschoolers by SES group --- p.95 / Chapter 4.13 --- "Differences in family food environments, feeding practices, eating habits and nutrient intakes of preschoolers by maternal education level and mother's employment status" --- p.95 / Chapter 4.14 --- Strengths and limitations of the study --- p.96 / Chapter Chapter Five: --- Conclusions and Recommendations --- p.99 / References --- p.100 / Appendices / Chapter A1 --- Invitation letter to principals (English version) --- p.114 / Chapter A2 --- Invitation letter to principals (Chinese version) --- p.117 / Chapter B --- Summary of the background information of the participating schools --- p.120 / Chapter C1 --- Consent form and letter to parent(s) or guardian(s) (English version) --- p.121 / Chapter C2 --- Consent form and letter to parent(s) or guardian(s) (Chinese version) --- p.123 / Chapter D --- Paper fans with food and physical activity pyramid pictures --- p.125 / Chapter E --- Health report --- p.126 / Chapter F1 --- Lifestyle questionnaire (English version) --- p.127 / Chapter F2 --- Lifestyle questionnaire (Chinese version) --- p.136 / Chapter G1 --- 24-hour dietary recall forms (English version) --- p.144 / Chapter G2 --- 24-hour dietary recall forms (Chinese version) --- p.150 / Chapter H --- Food photo booklet --- p.156 / Chapter I1 --- Table: Households receiving social benefits by paternal occupations (p<0.001) --- p.157 / Chapter I2 --- Table: Summaries some of the characteristics of the surveyed preschoolers by gender and altogether --- p.158 / Chapter I3a --- Table: Preschooler's parents' age --- p.159 / Chapter I3b --- Table: Parents age by SES --- p.159 / Chapter I4 --- Table: Factors considered by interviewee when buying food items --- p.160 / Chapter I5 --- Table: Cost as a factor of buying queried food items by SES income group --- p.161 / Chapter I6 --- Table: Frequencies of eating out or having takeaway meals in/from different types of caterers by SES group --- p.162 / Chapter I7 --- Type of utensils used to feed the preschoolers by SES group --- p.162 / Chapter I8 --- Preschoolers' activities during dinner by SES group --- p.163 / Chapter I9 --- "Proportion of interviewees with adequate fruit, vegetable, and both fruit and vegetable intakes per day by SES group" --- p.163