Purpose: Although previous research has associated the glycaemic load (GL) of a meal with cognitive functioning, typically the macro-nutrient composition of the meals has differed, raising a question as to whether the response was to GL or to the energy, nutrients or particular foods consumed. Therefore, the present study contrasted two breakfasts that offered identical levels of energy and macro-nutrients, although they differed in GL.
Methods: Using a repeated-measures, double-blind design, 75 children aged 5-11 years, from socially deprived backgrounds, attended a school breakfast club and on two occasions, at least a week apart, they consumed a meal sweetened with either isomaltulose (Palatinose™) (GL 31.6) or glucose (GL 59.8). Immediate and delayed verbal memory, spatial memory, sustained attention, reaction times, speed of information processing and mood were assessed 1 and 3 h after eating.
Results: The nature of the meals did not influence any measure of cognition or mood after an hour; however, after 3 h, children's memory and mood improved after the lower-GL breakfast. If children had eaten the lower-GL meal on the second day of testing, they were able to process information faster and had better spatial memory later in the morning.
Conclusions: Towards the end of a morning in school, having consumed a lower-GL breakfast resulted in better mood and aspects of cognitive functioning.