A diet that provides all the essential nutrients in sufficient quantity and in the correct proportions to promote good health. The six main classes of nutrients are carbohydrate, fat (lipid), protein, vitamins, minerals, and water. For the general population, health professionals suggest that a healthy, balanced diet is one that provides at least 50% of energy from carbohydrate, 35% from fat, and 15% from protein. Many sports nutritionists suggest that a balanced diet for athletes should include more carbohydrates with at least 60% of energy coming from this source, 30% or less from fat, and 10–15% from protein. The precise optimal quantities of each nutrient will vary with age, sex, and activity. Vitamins and minerals are required in relatively small amounts. In addition to nutrients, fibre is a necessary component of a healthy diet. In the past, athletes in training ate large amounts of protein, such as eggs, steaks, and milk, but it is now recognized that carbohydrate, not protein, is the best source of energy. Pasta parties have become almost a ritual for runners on the eve of a marathon race (see carbohydrate loading). See also sports nutrition.
Subjects: Sports and Exercise Medicine.