This essay discusses the impact of impaired lipoprotein metabolism on coronary heart disease risk and the role of dietary modifications in blood lipid concentration. It explores the various lipoprotein particles and their functions, as well as the causal factors associated with coronary heart disease. The essay also examines the lifetime risk of coronary heart disease, the relationship between cholesterol and mortality, and the impact of dietary modifications on blood lipid concentration. Additionally, it discusses the mechanisms responsible for changes in blood lipids and coronary heart disease risk due to dietary modifications.