In this study we assessed the acute effects of the consumption of varying amounts of fat and
fructose on the magnitude of postprandial
lipemia. Subjects were studied after an overnight fast on four separate mornings, ingesting in random order 5, 40, or 80 g fat, or 5 g fat plus 50 g
fructose.
Vitamin A (36 mg, or 120,000 U
retinol) was also given and blood was drawn at frequent intervals over the next 10 h for measurement of
triacylglycerol and
retinyl palmitate (RP) concentrations in plasma and the Sf > 400 and Sf 20-400
lipoprotein fractions. (Sf denotes flotation units.) In general, the postprandial
triacylglycerol response increased in plasma and in both
lipoprotein fractions as a function of both the baseline fasting
triacylglycerol concentration and the amount of fat ingested. However, no matter how high the fasting plasma
triacylglycerol concentration, there was no increase in the postprandial
triacylglycerol concentration in plasma or either
lipoprotein fraction after the 5-g oral fat load. The results of the measurements of RP concentration were somewhat similar in that there was a dose-dependent increase in the plasma and the Sf > 400
lipoprotein fraction in response to the higher fat loads. However, just the opposite was true in the Sf 20-400
lipoprotein fraction, for which the increase in RP concentration was inversely related to the size of the fat load.(ABSTRACT TRUNCATED AT 250 WORDS)