Postprandial lipemia in young men and women of contrasting training status

1 Human Muscle Metabolism Research Group, Department of Physical Education, Sports Science and Recreation Management, 3 Department of Human Sciences, Loughborough University, Loughborough, Leicestershire LE11 3TU, United Kingdom; and 2 Department of Sport and Exercise Sciences, University of Ulster at Jordanstown, Northern Ireland BT37 0QB This study compared the postprandial triacylglycerol (TAG) response to a high-fat meal in trained and untrained normolipidemic young adults after 2 days' abstinence from exercise. Fifty-three subjects (11 endurance-trained men, 9 endurance-trained women, 10 sprint/strength-trained men, 11 untrained men, 11 untrained women) consumed a meal (1.2 g fat, 1.1 g carbohydrate, 66 kJ per kg body mass) after a 12-h fast. Venous blood samples were obtained in the fasted state and at intervals until 6 h. Postprandial responses were the areas under the plasma or serum concentration-vs.-time curves. Neither fasting TAG concentrations nor the postprandial TAG response differed between trained and untrained subjects. The insulinemic response was 29% lower in endurance-trained men than in untrained men [mean difference 37.4 (95% confidence interval 62.9 to 22.9) µIU/ml × h, P = 0.01]. Responses of plasma glucose, serum insulin, and plasma nonesterified fatty acids were all lower for endurance-trained men than for untrained men. These findings suggest that, in young adults, no effect of training on postprandial lipemia can be detected after 60 h without exercise. The effect on postprandial insulinemia may persist for longer. triacylglycerol; insulin; dietary fat; endurance-trained; sprint/strength-trained