Influences of protein to energy ratios in breakfast on mood, alertness and attention in the healthy undergraduate students

Background: The high protein (HP) breakfast reduced gastric emptying and the most satiating macronutrient appears to be dietary protein. Few studies have investigated the effects of protein to energy ratio in breakfast on mood, alertness and attention. Objective: This study was designed to investigate whether the HP breakfast is more beneficial to mood, alertness and attention of the healthy undergraduate student than adequate-protein (AP) breakfast through the rising body temperature and remaining stable blood glucose or through other physiologic processes. Methods: Thirteen healthy male undergraduate students (18 23 y) were studied in a double-blind, randomized crossover design. Blood samples, body temperature, satiety, mood and Continuous Performance Test (CPT) were assessed after the consumption of two isocaloric breakfasts that differed in their protein and carbohydrate content: an HP breakfast (50%, 30%, and 20% of energy from protein, carbohydrate, and fat, respectively) or an AP breakfast (10%, 70%, and 20% of energy from protein, carbohydrate, and fat, respectively). Results: Consumption of an HP breakfast resulted in more steady glucose and insulin than AP breakfast consumption (p < 0.05). Satiety scores and body temperature were higher after HP breakfast consumption (p < 0.05). And most important, the positive mood and CPT scores were higher after HP breakfast than after AP breakfast intake (p < 0.05). Conclusion: HP breakfast can effectively stabilize postprandial serum glucose concentration and elevate postprandial temperature of healthy male undergraduate students. Our present findings demonstrate the relationship between HP breakfast and mood, alertness and attention. This study indicated that HP breakfast may enhance human performance probably by increasing the thermic effect of a food and elevating body temperature.