polypeptides dietary sources FAQ

Signs of a protein deficiency include weak muscle tone, swelling in the body, and thin, brittle hair.

Most adults on a 2,000-calorie diet require 50 grams (g) of protein daily.

Amino acids are the building blocks of protein. These molecules come together to form proteins. Your body uses them for many important functions, such as making hormones, building muscle, and repairing tissue. Your body needs 20 amino acids to work properly and makes many of these amino acids on its own. But your body can’t make nine of them. You have to get these amino acids through certain foods or supplements. They’re called essential amino acids and include:

Protein is present in every body cell, and an adequate protein intake is essential for keeping the muscles, bones, and tissues healthy. Protein plays a role in many bodily processes, including:

2 eggs equal around 12 g of protein, a bit less than a quarter of a person's daily intake. Pairing eggs with other protein sources, such as lean meats, can help increase the overall protein intake.

Your body uses amino acids to: Build muscle. Muscles are made mainly from protein, which amino acids help build. Grow and repair tissue. Many amino acids, such as leucine and methionine, are used to grow and repair tissues. They’re important for healing wounds and injuries. Make hormones. Amino acids help make many hormones. For example, phenylalanine is needed to produce the hormones epinephrine and norepinephrine. Other amino acids play a role in making thyroid and growth hormones. Boost the immune system. Amino acids are an important nutrient for immune cells. They’re needed for these cells to work properly. Make brain chemicals. Certain amino acids, such as tryptophan and phenylalanine, are used to make important chemicals in the brain, called neurotransmitters. These include dopamine and serotonin, which can affect your mood, sleep, and appetite. Provide energy. Although your body prefers to burn carbohydrates or fat for energy, it can use protein as needed. After breaking down protein, the amino acids supply energy. Support the digestive system. Amino acids help keep your digestive system running. They fuel the membrane that lines the small intestine and help your gut make key proteins and chemicals.