Diets are regulated selections of foods, specially designed and prescribed for medical and/or general nutritional reasons.

Eating the proper diet is critical for the health of individuals, groups with special medical and dietary needs, and entire populations afflicted with malnutrition.

The Food and Nutrition Board of the National Research Council of the National Academy of Sciences has determined dietary standards called Recommended Dietary Allowances (RDA). These standards explain the daily amounts of energy, protein, minerals, and fat-soluble and water-soluble vitamins needed by healthy males and females, from infancy to old age.

Experts in nutrition recommend a variety of foods and the maintenance of an ideal weight. Large amounts of fat, saturated fat, and cholesterol should be avoided. Individuals should consume adequate starch and fiber and avoid excess sugar and sodium.

The U.S. Department of Agriculture and the U.S. Department...