Obesity and Fatty Acid Flux Comparison Trials

This study will explore factors that affect obesity and obesity-related diseases in both Caucasians and African Americans. By looking at the rate at which the human body burns calories while at rest (resting energy expenditure, or REE) and at the rate at which fat travels through the blood (fatty acid flux), this study will examine the relationship between REE and fatty acid flux, both of which are determinants of obesity. Researchers will compare the test results of Caucasians and African Americans to determine if race has an effect on the relationship between REE and fatty acid flux. Volunteers must be between 18 and 49 years of age. Equal numbers of typical weight, overweight, and obese participants will be recruited. Candidates will be screened with a physical examination, electrocardiogram, and blood tests, and will be interviewed about diet and exercise habits, family and medical history, and employment. Participants will be placed on a two-week maintenance diet (prepared by a dietician to regulate and maintain calorie consumption) and must visit an outpatient clinic for weight measurement for 10 consecutive weekdays. During the two-week diet, participants will also undergo two 20-minute computerized scans to measure abdominal and body fat. At the end of the two weeks, participants will then be hospitalized for two days to allow researchers to conduct blood tests, oral glucose tests, and a physical examination to measure REE and fatty acid flux levels for comparison.