Healthful diets help children grow, develop, and do well in school. They enable people of all ages to work productively and feel their best. Food choices also can help to reduce the risk for chronic diseases, such as heart disease, certain cancers, diabetes, stroke, and osteoporosis, that are leading causes of death and disability among Americans. These nutrients are essential because the body cannot make them and must obtain them from food. Essential nutrients include vitamins, minerals, certain amino acids, and certain fatty acids.
Foods also contain other components such as fiber that are important for health.
Although each of these food components has a specific function in the body, all of them together are required for overall health. People need calcium to build and maintain strong bones, for example, but many other nutrients also are involved. The carbohydrates, fats, and proteins in food supply energy, which is measured in calories. Carbohydrates and proteins provide about 4 calories per gram. Foods that are high in fat are also high in calories.