View clinical trials related to Overweight.
Filter by:The aim of this study was to assess the effect of calcium/vitamin D supplementation (Caltrate 600 +D®) on body weight loss during a weight-reducing program
This study will look at gene expression (whether particular sets of genes are activated ["turned on"] or deactivated ["turned off"]) in overweight people as compared to non-overweight individuals. It will also investigate the potential role of inflammatory and protective substances that are produced naturally by the body within fat tissue. Findings from the study may lead to the development of ways to predict who will respond best to diet therapy. Healthy individuals between 25 and 45 years of age may be eligible for this study. Overweight subjects must have a BMI of 25 to 40, and non-overweight control subjects a BMI of 19 to 24.9. Candidates are screened with a medical history, physical examination, blood tests and electrocardiogram (EKG). They are instructed to record their dietary intake for a 3-day period and to collect their urine for a 24-hour interval. Participants have their food records reviewed a week after the screening visit. They are then scheduled for an overnight admission to the Clinical Center. Non-overweight subjects have one or two inpatient stays; overweight subjects have six inpatient stays plus frequent nutrition counseling sessions. During the 2-day hospital admissions, the following studies are performed: - DEXA scan to determine the percentage of body fat tissue. The subject lies on a table for about 15 to 60 minutes while the body composition is measured with very low-dose x-rays. - Single-slice CT scan to compare the amount of fat tissue under the skin with that in the abdomen. The subject lies on a table for about 5 to 10 minutes while the CT scanner measures body composition with very low-dose x-rays. - Subcutaneous fat microdialysis to investigate how weight loss affects the activity of fat tissue. A small tube (catheter) is placed into the fat tissue under the skin of the abdomen after numbing the skin with a local anesthetic. Fluid samples are collected through the tube. The procedure lasts overnight. In five non-overweight controls, a small amount of a substance called leukotriene B4 is put into their fat tissue to help adjust the instruments used in the study. - Air-displacement plethysmography to measure body composition. Subjects wear close-fitting clothing and enter a small capsule called a Bod-Pod. They breathe normally in the capsule while their body fat composition is studied. - Blood tests. Blood samples are drawn to analyze thyroid hormones, lipids, glucose, electrolytes, clotting factors, kidney function, red cells and DNA. - Euglycemic-hyperinsulinemic clamp to measure the effects of insulin in the body and to derive an index of insulin-sensitivity. Catheters are placed in a vein in an arm and in a vein in the hand on the other side of the body. Insulin and glucose are infused through the catheter in the arm, and blood samples are drawn from the catheter in the hand every 5 minutes to measure glucose levels. The test lasts about 2 hours. - Subcutaneous fat biopsy to find out how weight loss affects fat tissue characteristics, gene regulation and the ability to store glucose. A small sample of fat tissue is obtained from the skin of the abdomen after numbing the area with an anesthetic. - Nutrition counseling for overweight subjects. A nutritionist reviews the food record and designs a personalized diet for each participant. - Weight loss intervention for overweight subjects. In addition to individual nutritional counseling, group sessions are provided every 2 weeks during the first 3 months of the study and then every month.
Insulin resistance and a defect in early insulin secretion are risk factors for the development of type 2 diabetes mellitus. A recent longitudinal analysis which tracked the development of diabetes demonstrated that both insulin action and early insulin secretion deteriorate as individuals progress from normal to impaired glucose tolerance and then to diabetes. These results suggest that both inherent (apparent in normal glucose tolerant subjects who progress to diabetes and likely to have a genetic basis) and acquired (evident as individuals progress from NGT to IGT to diabetes and possibly environmental in origin) defects in insulin action and secretion contribute to the pathogenesis of type 2 diabetes. To identify the genetic and environmental determinants of diabetes we are continuing to determine: (1) if there are genes that segregate with metabolic risk factors for diabetes which might therefore be genetic markers for type 2 diabetes and (2) the mechanisms mediating genetic and environmental determinants of insulin resistance and impaired insulin secretion. <TAB> Volunteers for this study will be admitted to the clinical research ward where they will undergo several tests to determine body composition, oral and intravenous glucose tolerance and in vivo insulin action. In addition, in selected subjects, adipose and/or skeletal muscle tissue will be obtained by percutaneous biopsy for in vitro studies of gene expression and insulin action in these tissues. A transformed lymphocyte cell line will be established for each subject as a permanent source of DNA for genetic studies. Genetic markers for type 2 diabetes and insulin resistance will be sought by typing each individual at positional and functional candidate loci in the hopes of finding an association between these loci and obesity, insulin secretion, insulin resistance and/or type 2 diabetes. ...
We propose to add a treatment preference component to a larger study testing standard behavioral treatment (SBT) for weight loss without specific food group restriction vs standard behavioral treatment with gradual elimination of meat, poultry, and fish [a lacto-ovo-vegetarian (LOV) meal plan]. Eligible respondents will be randomized to one of two conditions: Treatment Preference-Yes/No. Individuals in the Treatment Preference-Yes will be assigned to their choice (SBT or SBT+LOV), those in Treatment Preference-No will be randomized to either SBT or SBT+LOV without regard to their preference.
Control of food intake, size and frequency of meals are critical to the development of obesity. The stomach signals feelings of fullness after a meal and therefore plays a role in control of calorie intake. It is unclear whether the approved appetite reducing drug sibutramine changes the function of the stomach. Differences in the way individuals respond to treatment with the appetite suppressant sibutramine may also explain why some people lose weight while others do not. This single center clinical study aims to compare functions of the stomach in healthy, overweight and obese individuals, and to evaluate the effects of the FDA-approved appetite suppressing medication sibutramine on weight loss and stomach functions in patients who are overweight or obese. The effect of individual differences in inherited genes on weight reduction with sibutramine will be tested.
The purpose of this study is to investigate the effect of a diet with either high or low glycemic index (GI) on ad libitum (free) food intake, body weight, fat mass and fat-free mass, risk markers for diabetes and cardiovascular diseases, energy expenditure and substrate oxidation after 10 weeks´ intake in slightly overweight subjects.
The purpose of this pilot study is to compare two strategies intended to improve the health of overweight older adults by improving body composition. One strategy, resistance training, is designed to preserve skeletal muscle mass. The other strategy, the use of a PPAR-γ agonist, is designed to enhance the loss of fat from visceral and skeletal depots. These strategies will be used in conjunction with a hypocaloric diet and will be compared to a hypocaloric diet alone to determine if either of these strategies are superior in reducing visceral fat and preserving muscle mass.
Recent research suggests that overweight persons who are physically active may be significantly less likely to develop health complications and less likely to die early when compared even with lean persons who are not physically active. Previous treatment programs for people who have struggled with their weight have focused almost entirely on weight loss as the main goal of treatment. Our research program has a different focus. We hope to improve health and healthy self esteem independent of body weight by focusing instead on increasing physical activity as the main goal of treatment. This is a small study designed to see if this approach would be appealing to persons who are struggling with their weight who are currently sedentary. It is designed for people who are otherwise fairly healthy for whom exercise is reasonably safe. Participants are randomly (by chance) assigned to participate in the experimental treatment program or instead to meet with their regular primary care doctor. Those who are assigned to meet with their regular doctor can access traditional weight loss resources such as Weight Watchers, Jenny Craig, Fitness centers etc... After the experiment is complete, these participants will have the opportunity to participate in the experimental treatment program.
The purpose of the present study is to determine whether weight gain may be prevented by a small group seminar-based two-year educational intervention on healthy lifestyle in freshmen at the Faculté de médecine de l'Université de Sherbrooke.
Habitual consumption of coffee may have substantial beneficial effects on glucose metabolism according to recent findings of epidemiological studies in the U.S., Europe, and Japan. However, data from longer-term human intervention studies with appropriate outcome measures are lacking. We will study the effects of caffeinated and decaffeinated coffee consumption on body fatness, insulin sensitivity and glucose tolerance that may underlie the observed associations with a lower risk of type 2 diabetes in a randomized controlled trial. We hypothesize that both caffeinated and decaffeinated coffee will improve insulin sensitivity and glucose tolerance. Before starting a larger, long-term intervention study, we will conduct a pilot study to test the feasibility of such a trial. The pilot study will be an 8-week parallel trial in 45 overweight individuals, who will be randomized to drinking 5 cups per day of 1) caffeinated coffee (n=15), 2) decaffeinated coffee (n=15), or 3) water (n=15). Body fatness (weight, waist circumference, bioelectrical impedance), insulin sensitivity (HOMA model), and glucose tolerance (oral glucose tolerance test) will be the primary outcomes. We will assess the adherence of participants to their assigned treatment by measuring serum caffeine concentrations, documentation of coffee use in diaries by the participants, and counting unused coffee packets. We will also obtain feedback from participants on how to improve compliance in a future trial. If successful, this study will form the basis for a definitive trial of coffee consumption, body fatness, and glucose tolerance. Given the extensive use of coffee and the rapidly increasing health burden of type 2 diabetes, such a trial would have important public health implications.