THE EFFECT OF TRIACYLGLYCEROL FATTY-ACID POSITIONAL DISTRIBUTION ON POSTPRANDIAL PLASMA METABOLITE AND HORMONE RESPONSES IN NORMAL ADULT MEN

The present study has examined the possibility that the positional dis tribution of fatty acids on dietary triacylglycerol (TAG) influences t he postprandial response to a liquid meal in adult subjects. Postprand ial TAG, non-esterified fatty acids (NEFA), ketones, glucose, insulin and gastric inhibitory polypeptide (GIP) responses were monitored in s ixteen normal adult male subjects over 6 h following consumption of te st meals containing dietary TAG in which palmitic acid was predominant ly on the sn-1 (Control) or sn-2 positions (Betapol). Plasma total TAG , chylomicron-rich TAG and chylomicron-poor TAG concentrations were id entical in response to the two test meals. The peak increase (mean (SD )) in chylomicron TAG was 0.85 (0.46) mmol/l after the Control meal an d 0.85 (0.42) mmol/l after the Betapol meal. Plasma glucose, insulin, GIP, NEFA and ketone concentrations were also very similar following t he two meals. It is concluded that dietary TAG containing saturated fa tty acids on the sn-2 position appear in plasma at a similar level and over a similar timescale to TAG in which saturated fatty acids are pr edominantly located on sn-1 or sn-3 positions. The results reported in the present study demonstrate that the positional distribution of fat ty acids on dietary TAG is not an important determinant of postprandia l lipaemia in adult male subjects, but do not exclude the possibility that different responses may occur when these dietary TAG are given lo ng term.