Meeting Your Protein Needs

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The Recommended Dietary Allowances for protein are based on body size, with extra amounts recommended for growth, pregnancy and breast feeding. More protein may be needed under conditions of stress such as fever, surgery or shock, and extra amounts may be advised by a physician.

Nitrogen equilibrium

The ideal level of protein intake allows the body to be in a state of nitrogen equilibrium, a condition nutrition scientists determine by measuring the amount of nitrogen waste resulting from use of body protein.

Protein intake

A recommendation of 0.8 gram of protein per kilogram of body weight has been established, based on the mixed protein that make up the typical diet, and allows a generous amount (30%) above the proven minimum need to cover individual differences. This amount allows 50 grams of protein per day for a man of average size, and 44 grams per day for a woman. This requirement is easily met by two 3-ounce servings of lean meat, fish, or poultry, a cup of milk, and an egg (although this may not be the ideal diet for some people who would have to look elsewhere for their protein).

Protein Myths

Over the years, protein has been the subject of much misunderstanding. As a result, a body of myths have arisen regarding the power of proteins. Here are some popular fallacies about protein, and the facts to set them straight.

  • Large amounts of protein are needed every day for good health. The body uses protein very efficiently, and a little goes a long way. The amount of protein in two chicken breasts will supply an average person's daily need.
  • Athletes need extra protein for strength and endurance. Research shows that no extra protein is used by the body during exercise. Protein supplements and high protein diets promoted for many athletes are expensive and can be stressful to the body. A balanced diet, with extra carbohydrates for needed calories, and a controlled training schedule are recommended for strength and endurance.
  • Red meat builds muscle. The body has a complex system for using proteins in all the food taken in and for all the functions it carries out. Meat protein does not go directly to the muscles but is processed in the body in the same way as all other proteins. The body can make protein from carbohydrates and, conversely, can take stored protein to use as an energy source for the carbohydrates missing from the diet.
  • Protein foods are low in calories. Proteins supply the same number of calories as carbohydrates -- 4 per gram. Protein foods such as beef can be high in fat and calories, whereas protein foods such as chicken or skim milk are low in fat and therefore low in calories.
  • Extra protein provides extra calories. The body's most efficient energy source is carbohydrates. For fighting fatigue, a balanced diet, adequate rest, and regular exercise are recommended.
  • A high-protein diet is the best way to lose weight. Proteins do not have the power to burn fat, as some people claim. High-protein diets are not balanced, can put a strain on the kidneys, and do not really change eating habits for the better. Experts recommend a balanced, low-calorie diet for weight loss.
  • Vegetables have no protein. Most vegetables contain some amount of protein; dried peas and beans contain very good amounts. However, vegetable protein is not as high quality as animal protein, although it can be made so by balancing vegetables in the diet.
  • Older people no longer need protein because they are not actively growing. While infants and children need the most protein per pound of body weight, everyone needs some protein for good health. Experts recommend that older people eat no less than 12% of their calories as protein, which is similar to the amount recommended for young people.
  • Cosmetics containing protein nourishes the skin and hair. Proteins cannot be absorbed into living cells through the skin and hair. These products have only a surface effect on the skin and hair.

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