Dissertation/Thesis Abstract

The Effects of Weight Maintenance on Lipid and Lipoprotein Metabolism in Men and Women Who Are Obese and Sedentary
by Hall, Christina, M.S., Southern Illinois University at Edwardsville, 2017, 38; 10608550
Abstract (Summary)

2Obesity is strongly associated with the development of metabolic and cardiovascular diseases. According to the World Health Organization, the prevalence of cardiovascular disease (CVD) mortality has increased both in the U.S. and globally. One of the primary risk factors for CVD and obesity-linked metabolic syndrome is dyslipidemia, defined as elevated circulating total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), triglyceride (Tg), and reduced high-density lipoprotein-cholesterol (HDL-C) concentrations. The benefits of weight loss on lipid and lipoprotein metabolism of obese, sedentary humans is well established; however, it remains unclear of the effect of weight maintenance on weight loss induced changes in blood lipids. Therefore, the purpose of this investigation was to determine the effects of weight loss and weight maintenance on lipid and lipoprotein-cholesterol concentrations in both men and women who were sedentary and obese. Participants (n = 66) were male (n = 20) and female (n = 46 ) ranging in age from 18–55 years. Only participants who met the criteria of a sedentary lifestyle and BMI between 25 and 45 kg/m 2 were accepted into the study. Participants completed a 3-month program that focused on weight reduction through caloric restriction (1200–1500 kcal/day) and increased physical activity (300 min/week). Following the 3-month weight loss program, participants were encouraged to maintain their weight loss using a weight maintenance program for an additional 3 months. Anthropometric, body composition, and blood samples were collected at baseline prior to weight loss and again at 3 months and 6 months following the baseline sample collection. Blood samples were analyzed for Tg, TC, LDL-C, and HDL-C concentrations. Anthropometric measures consisted of body mass, BMI, and waist circumference. Body composition, assessed by dual energy x-ray absorptiometry, included total body percent body fat. A repeated measures ANOVA was conducted to determine significant (p < 0.05) changes over time for blood lipid and lipoproteins and anthropometric dependent variables. When compared to baseline, the weight-loss program promoted a significant (p < 0.05) reduction of total body mass(8.6%), BMI(9.0%), waist circumference(7.9%), and total percent body fat(7.6%). Following weight maintenance at 6 months, results revealed that on average participants regained body mass such that total body mass, BMI, waist circumference, and total percent body fat were 2.0%, 1.0%, 1.5%, and 2.3%, respectively, significantly (p < 0.05) lower when compared to baseline. At 3 months, weight loss was associated with a significant (p < 0.05) reduction in LDL-C (–15.6%) and TC (–12.0%). Despite a modest weight-regain during the weight maintenance phase, the small transient weight loss was associated with a 15.0% significant (p < 0.05) reduction in Tg (–15%) when compared to baseline. Further, maintenance of weight loss led to a reduction in Tg concentrations not observed at the initial 3-month time point. The initial reductions of LDL and TC concentrations observed at 3-months; however, returned to baseline levels. These findings suggest that a weight loss program that incorporates an energy consumption of 1200–1500 kcal/day and 300 min/week of physical activity had a significant effect on the risk factors commonly associated with metabolic syndrome, specifically by reducing body weight, waist circumference, LDL levels, TC levels, and total body fat; however, a small weight regain eliminated the initial changes in blood lipids and lipoproteins originally observed after weight loss at 3months except for the decrease in Tg observed at 6 months.

Indexing (document details)
Advisor: Wooten, Joshua S.
Commitee: Smith, Bryan K., Webb, Benjamin
School: Southern Illinois University at Edwardsville
Department: Kinesiology and Health Education
School Location: United States -- Illinois
Source: MAI 57/02M(E), Masters Abstracts International
Subjects: Kinesiology, Physiology
Keywords: Lipid, Lipoprotein, Obese, Weight maintenance
Publication Number: 10608550
ISBN: 9780355571448
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