Italian breakfast in mind: The effect of caffeine, carbohydrate and protein on physiological state, mood and cognitive performance

Due to the bidirectional influence between eating and mental activity, there is a growing interest in the neurosciences in the potential of food to influence mental states. Breakfast is the most investigated meal since it is supposed to influence satiety, mood and cognitive performance for the rest of the day. However, there is insufficient consistency among studies to draw firm conclusions about the short-term influence of carbohydrates and proteins on self-reported physiological state and mood. In order to shed light on this topic, 40 young Italian adults were involved in a single-blind randomized counterbalanced crossover experiment, in which we asked them to report on a series of visuo-analogue scales their physiological (i.e., hunger, tiredness and thirst) and affective states (i.e., happiness, excitement, activeness and relaxation) and perform 2 computer-administered cognitive tasks (simple reaction time and forward digit span) before and after having breakfast with a bitter espresso coffee and a whole wheat or a protein croissant. Our data show that breakfast improves the self-reported mood and physiological state, and also short-term verbal memory assessed by means of the forward digit span: we suppose that both croissants and caffeine played an important role in such findings. As for the reaction times, the whole wheat croissant intake determined slower reaction time compared with the protein croissant, maybe due to the higher glycemic response induced by carbohydrate ingestion. Confirming the bidirectional relationship between mind and food intake, the present findings are significant for nutrition science, since mood, physiological state and cognitive performance play a substantial role in general well-being as well as in eating behavior.