Two Sources of Protein

Protein has historically been the mainstay of most meals and is one of the three macronutrients needed by the body for optimal health. Today, however, that roast beef and mashed potato dinner is often replaced with other types of high-protein entrées. Every cell in your body contains proteins, which act as the main structural component of your body, which is why this nutrient should be an essential part of every diet.

Complete Proteins

Foods containing all of the essential amino acids are considered complete proteins. Amino acids are the building blocks of protein, and nine essential amino acids must be obtained from the diet. There are also 11 non-essential amino acids, which can be made by the body. Animal foods provide the richest source of protein. However, animal proteins are usually higher in fat and almost always higher in cholesterol than other sources of protein. Examples of complete proteins include poultry, fish, milk, eggs and other dairy products.

Incomplete Proteins

An incomplete protein lacks one or more essential amino acid. Plant foods, while lacking in certain amino acids, need a complementary food in order to provide all of the essential amino acids. For instance, eating peanut butter on a slice of seven-grain bread will provide all of the essential amino acids. Plant foods containing protein include grains, legumes, seeds and nuts.

Alternatives

While meat is most often the most expensive item on the menu, there are fewer expensive protein alternatives. However, these alternatives may not always have an equivalent amino acid profile. For example one egg, ¼ cup of tofu or ½ ounce of nuts is equivalent in protein to 1 oz. of meat, fish or poultry.

Protein Content

Three ounces of ground beef, and 3 oz. of broiled flounder each have 21 g of protein. Three ounces of roast turkey has 25 g of protein. One cup of reduced fat milk has 8 g of protein and 1 oz. of American cheeses has 6 g of protein. One cup of cooked brown rice has 5 g of protein and one cup of red kidney beans has 15 g of protein. These two complementary proteins provide all of the essential amino acids. One banana has 1 g of protein, while 1 cup of broccoli has 6 g of protein.