Grazing, cognitive performance and mood

Two experiments were carried out to examine how spreading food intake between either two or four occasions would affect mood and cognition. The first experiment used 96 participants in a between subject design where participants received either two milkshakes at 09:00 and 13:00 or four (half nutrient content but same volume) milkshakes at 09:00, 11:00, 13:00 and 15:00. The results showed that verbal reasoning accuracy improved in the four-milkshake condition. The second experiment used 24 participants in a cross-over design. The breakfast and lunch were halved in one condition and not in the other so participants either ate breakfast and lunch, or four meals at the same times as experiment 1. Verbal reasoning accuracy was improved by spreading the intake over four meals such that errors were reduced by between 30 and 40%. Speed was also increased in a five-item (but not one-item) search task. Further research is now necessary to uncover the mechanisms that underlie these effects.