Effects of acute exercise on postprandial triglyceride response after a high-fat meal in overweight black and white adolescents

Abstract

Objective: We examined the effects of acute exercise on postprandial triglyceride (TG) metabolism following a high-fat meal in overweight black vs white adolescents.

Design and subjects: Twenty-one black and 17 white adolescents (12-18 yrs, body mass index 85th percentile) were evaluated twice, during control versus exercise trials, 1-4 weeks apart, in a counterbalanced randomized design. In the control trial, participants performed no exercise on day 1. In the exercise trial, participants performed a single bout of 60-min exercise (50% VO2 peak) on a cycle ergometer on day 1. On day 2 of both trials, participants consumed a high-fat breakfast (70% calories from fat) and blood was sampled for TG concentration in the fasted state and for 6 h postprandially.

Results: There was a significant main effect of condition on postprandial peak TG concentration (P=0.01) and TG area under the curve (AUC) (P=0.003), suggesting that independent of race, peak TG and TG-AUC was lower in the exercise trial vs control trial. Including Tanner stage, gender, total fat (kg) and visceral adipose tissue (VAT) as independent variables, stepwise multiple regression analyses revealed that in whites, VAT was the strongest (P<0.05) predictor of postprandial TG-AUC, explaining 56 and 25% of the variances in TG-AUC in the control and exercise trials, respectively. In blacks, VAT was not associated with postprandial TG-AUC, independent of trial.

Conclusion: A single bout of aerobic exercise preceding a high-fat meal is beneficial to reduce postprandial TG concentrations in overweight white adolescents to a greater extent than black adolescents, particularly those with increased visceral adiposity.

FIGURE 1

Fasting and postprandial TG concentration between control vs. exercise trials. Data are mean ± SEM. * Different from time −15 and 0 minutes within that condition (P<0.05). † Different from previous time point within that condition (P<0.05).

FIGURE 2

Fasting and postprandial TG concentration between low vs. high VAT group within each race. Data are mean ± SEM. * Different from time −15 and 0 minutes within that condition and VAT group (P<0.05). † Different from previous time point within that condition and VAT group (P<0.05).