Abstract
We investigated the effect of a fatty meal on plasma concentrations of lipids, apolipoproteins, and the cholesterol component of lipoproteins. Sixteen nonobese, healthy, asymptomatic males, 22–34 years of age, served as subjects for this study. None smoked, consumed more than two alcoholic drinks per day, or took any medication known to alter plasma lipids. After a 12 h fast, baseline plasma samples were obtained just before subjects consumed a high fat meal. The meal, standardized to a 70 kg individual, contained approximately 70 g fat, 580 mg cholesterol, and 1100 cal, with 56% of the calories coming from fat. During the 8 h following consumption of the meal, subjects rested quietly and consumed no food or beverages except water. Blood specimens were obtained hourly. There was a significant increase in plasma triglyceride (150% from baseline at 3 h, P < 0·0005). Very low density lipoprotein cholesterol (VLDL-C) concentrations increased 150% at 3 h (P < 0·0005) while low density lipoprotein cholesterol (LDL-C) concentration decreased 37% at 3 h (P < 0·005) when estimated by Friedewald's formula. No statistically significant differences were observed between fasting total cholesterol, high density lipoprotein cholesterol (HDL-C), HDL2-C, and HDL3-C, apolipoprotein AI (apo AI, AII), and B-100 concentrations and non-fasting samples. We conclude that plasma triglyceride concentration is significantly affected in the post-prandial state. As a result, VLDL-C and LDL-C when assessed by the Friedewald formula are also altered. A minimum of 8 h fasting is required to assess these concentrations accurately in this population. The concentrations of total cholesterol, HDL-C, HDL2-C, HDL3-C, apo AI, apo AII, and apo B-100 can be determined adequately using a non-fasting specimen.