Early Effects of Fasting and of Carbohydrate Ingestion on Lipids and Lipoproteins of Serum in Man

It is generally assumed that plasma lipoproteins function as carriers in the transport of fatty acids to and from the liver, fat depots, and peripheral tissues, but the roles of the various lipoprotein classes in this regard are not established. A previous study showed that the concentration of triglycerides in serum was lower several hours after the ingestion of a meal containing no fat than after an overnight fast (1). In the present study large quantities of glucose were fed to fasting young adults; the resulting alterations in various lipid constituents of ultracentrifugally separated lipoprotein classes were compared with changes observed during comparable periods of continued fasting. These comparisons showed that the concentrations of all major lipid constituents of the very low density lipoproteins of serum fall significantly after the ingestion of glucose. This finding suggests that very low density lipoproteins have a significant role in the transport of fatty acids derived from endogenous sources.