Most Complete Protein In Food

Protein is one of three macronutrients and should account for a substantial portion of your total caloric intake. You can find proteins, varying in quality, in both plant and animal sources. Protein molecules are formed from the linkage of up to thousands of amino acids. The human body requires 20 amino acids to function properly, but eight of them it cannot produce on its own. These eight essential amino acids must be consumed through dietary sources. Foods that contain all eight essential amino acids, considered "complete" proteins, have high biological value.

Most Complete Proteins

A way to measure the biological value of protein is to assess the amount of protein intake and then measure the rate of nitrogen uptake versus nitrogen excretion in the body. Biological value scales list protein sources based on how well the body actually uses these proteins. Eggs provide the most optimal amino acid mixture and offer the highest biological value of any dietary source of protein. Cow's milk is also a high-value protein, followed by fish and beef. Soybeans are the highest-quality plant source of protein, followed by polished rice, whole wheat, corn and dry beans.

Highest Protein Sources

While protein quality and content are generally related, they don't necessarily go together. Numerous foods have high protein content but lack certain amino acids and are not of high quality. The USDA provides a list of the top sources of protein based on common serving sizes. Duck, chicken, fish and turkey contain the most protein per serving with about 35 to 50 g. Cottage cheese is the non-meat source of protein that has the highest amount per serving, 31 g, while soybeans are the plant source with the highest amount, nearly 29 g per serving.

Protein Functions

Protein accounts for about 12 to 15 percent of the mass of a typical human body. Protein composes about 10 percent of brain mass and 20 percent of the mass of red blood cells. The amino acids in protein form the building blocks needed to synthesize RNA, DNA, and hormones and to activate numerous vitamins. Protein is also needed to synthesize tissue and repair damaged tissue. Protein plays a vital role in maintaining blood health and regulating the breakdown of all three macronutrients during energy metabolism.

Daily Protein Recommendations

According to the Food and Nutrition Board of the Institute of Medicine, protein should account for 10 to 30 percent of the caloric intake in children up to the age of 18 and for 10 to 35 percent of total calories in adults. An accurate way to determine how many grams of protein you need daily is to multiply your body weight in pounds by 0.38. For example, a 165 lb. man requires about 63 g of protein each day.