EFFECTS OF GRADED AMOUNTS (0-50 G) OF DIETARY-FAT ON POSTPRANDIAL LIPEMIA AND LIPOPROTEINS IN NORMOLIPIDEMIC ADULTS

Eight normolipidemic males ingested on separate days and in a random o rder five mixed meals containing 0, 15, 30, 40, or 50 g fat. Easting a nd postprandial blood samples were obtained for 7 h and chylomicrons a nd lipoproteins were isolated. The nonfat and 15-g fat meals did not g enerate noticeable postprandial variations except for HDL phospholipid s (P < 0.05). The serum and chylomicron triacylglycerol responses obta ined after the meals correlated positively with the amount of fat inge sted and peaked after 2-3 h. Serum free cholesterol and phospholipids increased and esterified cholesterol decreased postprandially in a dos e-response manner. At the same time, triacylglycerol-rich-lipoprotein triacylglycerols, esterified cholesterol, LDL free cholesterol, HDL tr iacylglycerols, phospholipids, and free cholesterol increased whereas LDL and HDL esterified cholesterol decreased when the amount of ingest ed fat increased. The data showed that increasing the amount of fat in the usual range of ingestion (0-50 g) led to stepwise increases in th e postprandial rise of chylomicron and serum triacylglycerols and indu ced marked changes in serum lipoproteins postprandially. The existence of a no-effect level of dietary fat (15 g) on postprandial lipemia an d lipoproteins in healthy adults was shown.