Diet and High-Density Lipoprotein Metabolism

High levels of plasma low-density lipoprotein (LDL) cholesterol constitute a major risk factor for coronary heart disease. Conversely, plasma high-density lipoprotein (HDL) cholesterol and apolipoproteins A-I and A-II, the major protein constituents of HDL, are inversely related to the disease. One approach to lowering LDL and increasing HDL-cholesterol is by dietary means. The recommended diet is low in saturated fat, total fat, and cholesterol. Since the protein content of most diets is relatively constant, a low-fat diet would result in an increase in dietary carbohydrate. The present studies were designed to determine the effect of dietary fatty acids and carbohydrate on lipoprotein metabolism. All studies were performed with normal subjects under metabolic ward conditions with solid-food diets.