The study assessed the impact of consuming diets enriched in hydrogenated and other fats on a) plasma lipids and lipoprotein concentrations, b) apolipoproteins A-1 and B and Lp(a) concentrations, c) parameters related to HDL cholesterol [particle size, composition, subfraction distribution (HDL2 and HDL3, and HDL with and without A-II)], d) susceptibility of LDL to oxidation, e) activities of lecithin cholesterol acyltransferase (LCAT) and cholesterol ester transfer protein, and f) rates of endogenous cholesterol synthesis.