Health Topics for Nutrition

Protein: how much is enough?

Protein is the major building block for the body. It is the primary component of muscle and is essential for the formation of all cells. Protein is also critical for optimum immune function. When deprived of protein, the body is more susceptible to allergies, infection, and disease. Anyone who is recovering from surgery, a wound, or burn may require more protein to promote tissue repair during healing.

Proteins used by the body are made up of several different amino acids. The body is capable of making some of the amino acids, but not all of them. The amino acids that it cannot make are called "essential" amino acids because they must be consumed in the food we eat. Eat a variety of foods to be sure that you get all of the amino acids you need. Lack of protein can cause growth failure, loss of muscle mass, decreased immunity, weakening of the heart and respiratory system, and death.

In order to get adequate protein from our diet we need to eat a variety of foods each day. The most common source of protein in the American diet is meat. Milk and most dairy products are also rich in protein. Egg white is said to have the most complete protein. Like the egg's yoke, many of these animal sources of protein can also be high in fat. To avoid too much fat, select leaner cuts of meat, fish, and poultry. Cook without adding fat by baking, broiling, barbecuing, or boiling your meat.

Vegetarians can also get adequate protein in their diets by eating beans and lentils as well as a variety of vegetables and grains. Certain beans, when eaten together with certain other beans or grains, can make a complete protein. An example is eating corn with black beans. Nuts and seeds are also good sources of protein.

How much protein do we need? Most Americans get more than enough protein in their daily diets. The average adult needs 8 grams of protein per 20 pounds of body weight. This equates to 45 to 70 grams of protein daily for most adult females and males, respectively. Yet, we generally consume twice that much.

Balance carbohydrates with proteins. Eat a variety of foods to be sure that you get all of the amino acids you need. Soybeans, tofu, and other soy-based foods are excellent alternatives to red meat. Eat 2 to 4 servings of soy a week. A high protein diet (such as red meat, cheese, and full-fat dairy products) that is high in saturated fat and low in vitamins and minerals may increase the risk for heart disease. Cut back on highly processed carbohydrates (like commercially prepared foods) and increase protein to improve levels of blood triglycerides and HDLs.

Digesting lots of protein takes calcium. Eating a high protein diet for a few weeks will not affect your bone strength. However, eating a high protein diet for a long time may increase the risk of weakening bone. High protein diets should be used with caution, if at all. If you are overweight you do not necessarily need more protein. Some athletes feel they will perform better and increase their muscle mass if they follow a high protein diet. However, this has not been proven in scientific studies.

The USDA Food Guide Pyramid recommends that adults get 2 to 3 servings of meat and 2 to 3 servings of milk group products everyday. Low-fat selections are best. A serving of meat is 3 to 4 ounces or about the size of a deck of cards. One serving of milk is one cup and for cheese, a serving is about 2 ounces.

Last Reviewed 2005

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.

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