Background: The mitigating effect of exercise on postprandial lipemia may b
e attributable to the energy deficit incurred.
Objective: We aimed to compare the effects of prior exercise and an equival
ent energy intake deficit on postprandial lipemia.
Design: Eleven postmenopausal women participated in 3 oral-fat-tolerance te
sts after undergoing different treatments on the preceding day: control (su
bjects refrained from exercise and consumed a prescribed diet), exercise (s
ubjects consumed the same diet but walked briskly for 90 min), and intake r
estriction (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 t
hey 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 concentrat
ion was 19% and 17% lower than the control and intake restriction values, r
espectively (P < 0.05 for both). Compared with the control trial, exercise
reduced postprandial Lipemia by a mean of 20% (P < 0.05), whereas intake re
striction reduced it by 7% (NS). In the exercise trial, fasting and post pr
andial fatty acid concentrations were higher than control values (P < 0.05)
. Exercise, but not intake restriction, reduced postprandial insulin concen
trations.
Conclusions: The results suggest that the effect of exercise on postprandia
l lipid metabolism was greater than and different from that attributable to
the energy deficit incurred.