Epidemiological and clinical studies have established that high levels of high density lipoprotein (HDL) cholesterol are associated with a reduced incidence of coronary heart disease (CHD). Blacks show significantly higher high-density lipoprotein (HDL) and lower very low-density lipoprotein (VLDL) levels than whites. This may explain some of the variation in the clinical expression of atherosclerotic CHD in black and white patients. The metabolic basis for the black-white difference in lipoprotein is not known. We hypothesize that blacks may have an enhanced lipoprotein lipase activity resulting in more efficient clearance of blood VLDL and chylomicron triglyceride than whites, higher blood levels of HDL cholesterol and lower levels of VLDL cholesterol and triglyceride levels. The specific aims of the study include the following: 1) To determine if the activities of lipoprotein lipase are higher and hepatic triglyceride lipase lower in black than white healthy young adults; 2) To quantify fasting lipoproteins and postprandial triglyceride clearance in healthy, young Vietnamese-American and Hispanic American adults; 3) To examine racial differences in the magnitude of postprandial lipemia and determine if these differences are modified by apolipoprotein E genotype; 4) To assess the contribution of diet, exercise, and health habits on cardiovascular risk factors in young men and women of different racial/ethnic groups. When completed, these studies will provide further insight into the metabolic, racial and genetic determinants of human lipoprotein metabolism.