How to get the right amount of dietary protein

With so much focus given lately to the benefits of protein, you might assume that it should make up the bulk of the diet, but this is not the case. Here are some tips on getting the right amount of dietary protein.

• In an ideal balanced diet, only 10 to 12 percent of daily calories should come from protein.
• A 85 gram (three ounce) serving of meat, fish or poultry contains about 21 grams of protein, one egg contains six grams, one cup of milk contains eight grams, and 125 grams (half a cup) cooked lentils contains eight grams.
• With the exception of oils and pure sugar, all foods contain at least some protein, but its quality varies according to the variety of amino acids it provides.
• Animal protein (with the exception of gelatin) provides all nine essential amino acids in the proportions required by the body and is therefore referred to as complete, or high-quality, protein.
• Plant proteins (with the exception of soy, which is almost as complete as animal food) lack one or more of the essential amino acids. Because not all plant foods lack the same amino acids, the body can build a complete protein if these foods are combined in such a way that they complement each other.
• Grains are high in the essential amino acid methionine, but they lack lysine. This essential amino acid is plentiful in dried beans and other legumes, which are deficient in methionine. By combining a grain with a legume, you can obtain the complete range of amino acids.

Interestingly, low-meat ethnic diets all have dishes that provide complementary proteins: the refried beans and corn tortillas of Mexico; the rice and dahl of India; the tofu, rice, and vegetable combinations in Asian cuisine; and the chickpeas and bulgur wheat in Middle Eastern dishes.

• Even strict vegetarian diets can supply ample protein by combining complementary grains and legumes. However, if an essential amino acid is missing from the diet, the body breaks down lean tissue to get it.
• Moderate cooking makes protein easier to digest because heat breaks down some of the bonds that join amino acids together.
• Overcooking can cement some amino acids together, making the protein more difficult to digest and to break down into individual amino acids.

High-protein, low-carbohydrate diets are a popular weight-loss regime.

• While people do lose weight on these diets, there is concern about the effects of high protein and high fat intakes on kidney function, bone health, cardiovascular function and cancer rates.
• A diet that is high in protein is likely to be low in fruits and consequently low in the numerous beneficial compounds that fruits provide.

The typical North American diet provides more protein than the human body needs. This does not pose a serious threat for healthy persons, but too much protein adds to the workload of the kidneys and liver.

• People with diseases affecting the kidneys and liver are often put on a low-protein diet.
• Purified protein and amino acid powders or pills are often promoted as high-energy, muscle-bulking supplements for athletes and bodybuilders, as well as weight-loss aids for dieters.
• There is no evidence that athletes benefit from high protein intakes. A balanced diet provides all the needed protein; any excess is just excreted.