Nutrition, vigilance et sommeil : relations biologiques et comportementales

Both amount and content of meals, and more generally food intake affect sleep duration and its content. There is a strong relationship between energy intake and wakefulness, and previous studies showed that food ingestion per se increased objective signs of sleepiness. The role played by the cellular energy status is discussed in the present paper. Even, the effects of peptides produced either in peripheral tissues, such as bombesin, leptin, insulin, ghrelin, or at the central level such as orexins or neuropeptide Y are also reported in the present review. Moreover, some specific macronutrients or food constituents affect vigilance.Both carbohydraterich and fat-rich meals cause an enhancement in sleepiness in human. These findings led to suggest that subjects eating meals that differed greatly from standard food, either by increasing carbohydrate or fat, induced sleepiness. The role played by specific amino acids such as tryptophan or tyrosine is discussed. Sleep deprivation is a growing problem in our industrial societies and increased sleepiness related to shift and night work is also a major problem that needs to be taken into account for maintaining health. The prevention of nutritional conditions able to increase alterations in vigilance should be carefully considered. Excluding environmental conditions of high energy expenditure, the consumption of low caloric meals is recommended. These meals should provide standard quantities of macronutrients, except when subjects are very active ; under these conditions, high-carbohydrate meals are needed. The potential use of caffeine is specified, in order to increase walkefulness.