Protein

Proteins are indispensible parts of organisms and participate in every process within cells. Many proteins are enzymes that catalyze biochemical reactions, and are vital to metabolism. Protein is also a necessary part of our diet because of the essential amino acids it provides.

Deficiencies: Deficiencies of protein or of one or more of the essential amino acids will lead to reduced growth in children or loss of muscle mass in adults. Susceptibility to disease will be increased, and in extreme cases, death may result. Protein-energy malnutrition is often described in its two extreme forms: marasmus which is a generalized wasting due to a deficiency of both protein and energy, and kwashiorkor which is characterized by edema and a deficiency of both protein quantity and quality.

Food sources: Virtually all unprocessed foods contain protein, and the protein of these foods is characterized by the quantity and ratio of indispensable amino acids contained therein. Animal proteins (meat, milk, eggs) are considered to be excellent in both protein quantity and quality. Plant proteins vary in protein quantity and quality. Members of the bean family (soybeans, kidney beans, navy beans, split peas, lentils, and lima beans) are rich in protein, and the protein quality is quite good as well.

2000-Calorie Diet Recommendations

Shown below are the reference numbers used to compute the Daily Value percentages that appear on the Nutrition Facts labels on foods sold in the U.S. These numbers are meant to approximate the nutrients needed for the average person consuming 2000 calories per day.

Click any of the vitamin or nutrient names below to learn more about the importance of each element, and to see detailed dietary allowances for specific population groups.

***Daily Value recommendations are based on a 2000-calorie diet. Recommendations for individuals will vary depending on gender, age, weight, and other factors.