The study determines the relations of free-living diet and exercise to total body percent fat ( percent BF), visceral adipose tissue and CV fitness in black and white boys and girls of varying socioeconomic status (SES). The study also determines the relations of fatness and fitness to different CVD risk factors. A total of 800 15 to 18 year olds, 200 in each ethnic and gender subgroup will be recruited. Diet will be assessed with seven 24-hour recalls, and exercise with two seven-day recalls and heart rate monitoring. Percent body fat will be measured with dual-energy x-ray absorptiometry, visceral adipose tissue with magnetic resonance imaging and CV fitness with a multi-stage treadmill test. Measurements will be made of major fatness- and fitness-related CV disease risk factors (e.g., total cholesterol:HDL cholesterol ratio, insulin, systolic blood pressure, left ventricular mass indexed to height, fibrinogen). Multivariate and univariate analyses will be conducted to determine relationships.