THE EFFECT OF TEST MEAL MONOUNSATURATED FATTY-ACID SATURATED FATTY-ACID RATIO ON POSTPRANDIAL LIPID-METABOLISM

Epidemiological evidence shows that a diet high in monounsaturated fat ty acids (MUFA) but low in saturated fatty acids (SFA) is associated w ith reduced risk of CHD. The hypocholesterolaemic effect of MUFA is kn own but there has been little research on the effect of test meal MUFA and SFA composition on postprandial lipid metabolism. The present stu dy investigated the effect of meals containing different proportions o f MUFA and SFA on postprandial triacylglycerol and non-esterified fatt y acid (NEFA) metabolism. Thirty healthy male volunteers consumed thre e meals containing equal amounts of fat (40 g), but different proporti ons of MUFA (12, 17 and 24% energy) in random order. Postprandial plas ma triacylglycerol, apolipoprotein B-48, cholesterol, HDL-cholesterol, glucose and insulin concentrations and lipoprotein lipase (EC 3.1.1.3 4) activity were not significantly different following the three meals which varied in their levels of SFA and MUFA. There was a significant difference in the postprandial NEFA response between meals. The incre mental area under the curve of postprandial plasma NEFA concentrations was significantly (P = 0.03) lower following the high-MUFA meal. Regr ession analysis showed that the non-significant difference in fasting NEFA concentrations was the most important factor determining differen ce between meals, and that the test meal MUFA content had only a minor effect. In conclusion, varying the levels of MUFA and SFA in test mea ls has little or no effect on postprandial lipid metabolism.