Postprandial lipemia: effects of exercise and restriction of energy intake compared

Background: The mitigating effect of exercise on postprandial lipemia may be attributable to the energy deficit incurred. Objective: We aimed to compare the effects of prior exercise and an equivalent energy intake deficit on postprandial lipemia. Design: Eleven postmenopausal women participated in 3 oral-fat-tolerance tests after undergoing different treatments on the preceding day: control (subjects refrained from exercise and consumed a prescribed diet), exercise (subjects consumed the same diet but walked briskly for 90 min), and intake restriction (subjects' food intake was restricted to induce the same energy deficit, relative to control, as brought about by the 90-min walk). Venous blood samples were obtained after subjects fasted overnight, 30 min after they ate a mixed, high-fat meal (1.70 g fat, 1.65 g carbohydrate, and 99 kJ/kg fat-free body mass), and hourly for the next 6 h. Results: In the exercise trial, the mean fasting triacylglycerol concentration was 19% and 17% lower than the control and intake restriction values, respectively (P < 0.05 for both). Compared with the control trial, exercise reduced postprandial Lipemia by a mean of 20% (P < 0.05), whereas intake restriction reduced it by 7% (NS). In the exercise trial, fasting and post prandial fatty acid concentrations were higher than control values (P < 0.05). Exercise, but not intake restriction, reduced postprandial insulin concentrations. Conclusions: The results suggest that the effect of exercise on postprandial lipid metabolism was greater than and different from that attributable to the energy deficit incurred.