Nutrition: At a Glance
Healthy eating is really pretty simple (though not easy):
If your medical condition requires a special diet, follow it.
For a full discussion of nutrition, see Overview of Nutrition.
See also ChooseMyPlate.
Developing healthy eating habits is important, especially for children.
In the United States, general guidelines for a healthy diet, including recommended dietary allowances (RDAs) for most vitamins and minerals, have been developed. The RDAs are intended to meet the needs of healthy people. Special diets are required by people who have certain disorders or food sensitivities.
Carbohydrates, proteins, and fats supply 90% of the dry weight of the diet and 100% of its energy. All three provide energy (measured in calories), but the amount of energy in 1 gram (1/28 ounce) differs: 4 calories in a gram of carbohydrate or protein and 9 calories in a gram of fat. These nutrients also differ in how quickly they supply energy. Carbohydrates are the quickest, and fats are the slowest.
See how many calories you need each day: Estimate your daily energy expenditure.
Are you at a healthy body weight for your height? Calculating your body mass index is one way to find out.
The body needs protein to maintain and replace tissues and to function and grow. Proteins consist of amino acids. The body synthesizes some of them from components within the body, but some of them—called essential amino acids—must be consumed in the diet.
If people do not consume enough calories, protein may be used for energy. If people consume more protein than they need, it is broken down into components that are stored as fat.
Not all fats are created equal: See Where’s the Fat?