No other class of biomolecules has such a broad variety of functions. Requirements For persons of average weight, the RDA of protein is 44-60 g, depending on age and sex. A higher intake is recommended under conditions of stress, infection, injury, and pregnancy. The animal proteins of meat, eggs, and dairy products closely match human proteins in amino acid composition, thus animal proteins are complete proteins. An exclusive vegetarian diet cannot meet all of your nutritional needs unless supplemented with vitamin B 12 and essential amino acids.
Proteins are our chief dietary source of nitrogen.
Someone in positive nitrogen balance is in a period of growth, like a child or pregnant woman. Negative nitrogen balance means that body proteins are being broken down and used as fuel. This condition may occur if carbohydrate and fat intake are insufficient to meet the need for energy. Nitrogen balance is affected by growth hormone and sex hormones that promote protein synthesis. Glucocorticoids promote protein catabolism during times of stress.