The influence of the glycaemic index of an evening meal on the glycaemic response to breakfast and subsequent cognitive performance in young adults

Abstract

It has been reported that the glycaemic response to consumption of a high glycaemic index (GI) breakfast is higher after consuming a high GI evening meal compared to a low GI evening meal. However, no research has investigated how this ‘previous meal effect’ may influence cognitive performance. Eight young, healthy, male participants consumed a low GI and a high GI evening meal, in a counterbalanced order. In each condition, the following morning a high GI breakfast was consumed. Immediate recall, delayed recall, recognition, and attention were assessed before and after breakfast, and blood glucose was measured throughout. The blood glucose profiles following each meal were not significantly different between the high and low GI meals. However, there was an association between evening and morning glycaemic responses, with higher evening glycaemic responses being associated with higher morning glycaemic responses. Generally, there were no associations between GI and cognitive performance or between morning glycaemic response and cognitive performance. In conclusion, the glycaemic response to an evening meal can influence the glycaemic response to breakfast. This has implications for research investigating any associations between blood glucose, nutritional manipulations, and cognitive performance.