Exercise and a diet high in monounsaturated fat: Is this the optimal strategy for reducing postprandial triacylglycerol concentrations in young women?

This study examined the combined effects of exercise and monounsaturated fat (MUFA) meals on postprandial triacylglycerol (TAG) concentrations in young women. Nine healthy females completed four, 2-day trials in randomised order : olive oil-exercise (Olive-Ex), butter-exercise (Butter-Ex), olive oil-no exercise (Olive-Con), butter-no exercise (Butter-Con). Each trial was conducted during the follicular phase. For the exercise trials participants walked or ran on a treadmill for 60 min at 60% of maximum oxygen uptake on the afternoon of day 1. On the morning of day 2 participants reported to the lab after an overnight fast and a baseline blood sample was taken, then consumed a test meal comprising 55% fat, 39% carbohydrate, 6% protein and 65kJ·kg^-1 body mass. The fat in this meal was supplied from either olive oil (saturated fat, SFA : 15% ; MUFA : 76% ; polyunsaturated fat, PUFA : 9%) or butter (SFA : 71% ; MUFA : 26% ; PUFA : 3%). Further blood samples were collected at hourly intervals for 6 h. Significant (P<0.05) trial, time and trial x time interaction effects were obtained for plasma TAG concentration. The Olive-Ex trial induced the lowest TAG area under the curve concentration among the four trials (Olive-Ex : 4.40±0.13 ; Butter-Ex : 4.95±0.39, Olive-Con : 5.62±0.42 ; Butter-Con : 5.91 ±0.34). Area under the curve values on this trial were 26% lower than values obtained on the ButterCon trial (P = 0.022). These data suggest that the optimal strategy for reducing postprandial TAG concentration in young females is to exercise regularly and to consume diets high in MUFA rather than SFA.