The effect of the glycemic index of an evening meal on the metabolic responses to a standard high glycemic index breakfast and subsequent exercise in men

The study investigated the effect of the glycemic index of an evening meal on responses to a standard high glycemic index (HGI) breakfast the following morning. The metabolic responses to exercise 3 hours after breakfast were also investigated. 7 active males completed 2 trials. In each trial, participants were provided with an evening meal on day 1, either HGI or LGI (high or low glycemic index) carbohydrates. On day 2, participants were provided with a standard HGI breakfast, then performed a 60 minute run 3 hours later. Plasma glucose and serum insulin concentrates following breakfast were higher in the HGI trial compared to the LGI trial. During exercise there were no differences in substrate utilization. Results suggest that consuming a single LGI evening meal can improve glucose tolerance at breakfast but the metabolic responses to subsequent exercise were not affected.