Physical Activity Offsets the Negative Effects of a High-Fructose Diet

Objective: This study aimed to determine the interaction between a high-fructose diet and PA levels on postprandial lipidemia and inflammation in normal-weight, recreationally active individuals. Methods: Twenty-two men and women (age, 21.2 +/- 0.6 yr; body mass index, 22.5 +/- 0.6 kg.m(-2)) consumed an additional 75 g of fructose for 14 d on two separate occasions: high physical activity (PA) (approximately 12,500 steps per day) (FR+active) and low PA (approximately 4500 steps per day) (FR+inactive). A fructose-rich test meal was given before and at the end of each intervention. Blood was sampled at baseline and for 6 h after the meal for triglycerides (TG), VLDL, total cholesterol, glucose, insulin, tumor necrosis factor-alpha, interleukin 6, and C-reactive protein. Results: Log-transformed TG area under the curve (AUC) significantly increased from before (10.1 +/- 0.1 mg.dL(-1) x min for 6 h) to after (10.3 +/- 0.08 mg.dL(-1) x min for 6 h, P = 0.04) the FR+inactive intervention, with an 88% increase in Delta peak TG (P = 0.009) and an 84% increase in Delta peak VLDL (P = 0.002). Delta Peak interleukin 6 also increased by 116% after the FR+inactive intervention (P = 0.009). Insulin total AUC significantly decreased after FR+ active intervention (P = 0.04), with no change in AUC after the FR+ inactive intervention. No changes were observed in glucose, tumor necrosis factor-alpha, and C-reactive protein concentrations (P > 0.05). Conclusions: Low PA during a period of high fructose intake augments fructose-induced postprandial lipidemia and inflammation, whereas high PA minimizes these fructose-induced metabolic disturbances. Even within a young healthy population, maintenance of high PA (912,500 steps per day) decreases susceptibility to cardiovascular risk factors associated with elevated fructose consumption.