British Journal of Nutrition

Effects of triacylglyceride positional structure on lipid metabolism

The effect of triacylglycerol fatty acid positional distribution on postprandial plasma metabolite and hormone responses in normal adult men

A. Zampelasa1, Christine M. Williamsa1*, Linda M. Morgana1, J. Wrighta1 and P. T. Quinlan

a1 The Nutritional Metabolism Research Group, School of Biological Sciences, University of Surrey, Guildford GU2 5XH

a2 Unilever Research, Colworth House, Sharnbrook, Bedford MK44 1LQ

Abstract

The present study has examined the possibility that the positional distribution of fatty acids on dietary triacylglycerol (TAG) influences the postprandial response to a liquid meal in adult subjects. Postprandial TAG, non-esterified fatty acids (NEFA), ketones, glucose, insulin and gastric inhibitory polypeptide (GIP) responses were monitored in sixteen normal adult male subjects over 6 h following consumption of test meals containing dietary TAG in which palmitic acid was predominantly on the sn-1 (Control) or sn-2 positions (Betapol). Plasma total TAG, chylomicron-rich TAG and chylomicron-poor TAG concentrations were identical 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 and 0 85 (0 42) mmol/l after the Betapol meal. Plasma glucose, insulin, GIP, NEFA and ketone concentrations were also very similar following the two meals. It is concluded that dietary TAG containing saturated fatty 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 predominantly located on sn-1 or sn-3 positions. The results reported in the present study demonstrate that the positional distribution of fatty acids on dietary TAG is not an important determinant of postprandial lipaemia in adult male subjects, but do not exclude the possibility that different responses may occur when these dietary TAG are given long term.

(Received September 14 1992)

(Revised February 04 1993)

(Accepted April 27 1993)

Footnotes

* For reprints.