Hypothesis is that premenopausal black women have more coronary heart disease than premenopausal white women because of their greater responsiveness to dietary factors in the socioeconomic environment of the US. To be studied are rise in plasma total and LDL cholesterol concentration after high-CIS diet; plasma levels of apolipoprotein B100; lipemic response after standard test meal high in saturated fat and cholesterol; LDL susceptibility to oxidative modification, and other dietary related blood studies.