Lack of effect of meal fatty acid composition on postprandial lipid, glucose and insulin responses in men and women aged 50-65 years consuming their habitual diets.

The aim of the study was to determine the effect of consuming meals with different fatty acid compositions on the postprandial changes over 6 h in plasma triacylglycerol, NEFA, total cholesterol, glucose and insulin concentrations in middle-aged men and women. Men (n 11; 58 (5) years) and women (n 11; 56 (4) years) consumed four test meals with a similar macronutrient energy content in random order: a reference meal based on the habitual pattern of fatty acid intake in the UK, a meal with an increased (155 %) linoleic acid (LA) to alpha-linolenic acid (alphaLNA) ratio (high LA:alphaLNA), a meal with increased (23 %) MUFA content (high MUFA) and a meal with increased (583 %) EPA and DHA content (high EPA+DHA). The high-LA:alphaLNA and high-EPA+DHA meals selectively increased the ratio of LA to alphaLNA (men 341 %; women 310 %) and the EPA+DHA (men 414 %; women 438 %) concentration in plasma triacylglycerol. The high-MUFA meal did not alter the change in MUFA content of the plasma. Plasma triacylglycerol, NEFA, glucose and insulin, but not total cholesterol, concentrations changed significantly after each meal. There was no significant effect of meal fatty acid composition or gender on maximum change in concentration, time to maximum concentration or area under the curve of any of the metabolites measured in the blood. These results suggest that differences in meal fatty acid composition exert little or no effect on postprandial changes in plasma lipids, glucose and insulin concentrations.