Pay attention to macronutrients (carbohydrates/protein/fat) and eat them in proportion to each other. You'll need to do some reading and a bit of experimentatio

Pay attention to macronutrients (carbohydrates/protein/fat) and eat them in proportion to each other. You'll need to do some reading and a bit of experimentation to find what fits your needs best. Getting the right balance of macronutrients will postively affect your mental acuity. That and exercise. If you're getting enough exercise, it's much easier to get good sleep. Once these big picture things are in place, then worry about micronutrients (vitamins).