An object of the present invention is to provide a food etc. containing histidine in a composition and/or form not conventionally present, and provide a food etc. having a new function based on histidine, more particularly, a food etc. having a less fear of causing side effects and capable of effectively improving mental energy. The present invention provides a food etc. for improving mental energy, which is in a unit package form per meal and contains, in the unit, not less than 0.3 g of histidine as an ingestion amount per meal.