The study will take 120 healthy nondiabetic African American men and women (ages 18-50) grouped by sex (60 men and 60 women) and body mass index 3 subgroups; nonobese, overweight and obese). Diabetes undeniably increases the risk of heart disease. Therefore patients suffering from diabetes will not be included in the study. Candidates for the study will undergo a series of tests and examinations over 5 outpatient visits. Subjects will have body fat analyses, resting energy expenditure measurements, an EKG (electrocardiogram), and specific blood tests.