Proteins

Proteins are essential parts of organisms and participate in every process within cells. Many proteins are enzymes that catalyze biochemical reactions and are vital to your metabolism. Other proteins are important in cell signaling, immune responses, cell adhesion, and the cell life cycle. Proteins are also necessary in the animal diet, (humans being part of the animal world) since animals cannot synthesize all the amino acids they need and must obtain essential amino acids from food. Through the process of digestion, animals break down ingested protein into free amino acids that are then used in metabolism, recuperation, tissue building and repairing.

The body is continually breaking down protein from tissues, so all adults – even those who don't practice sports - need to include adequate protein in their diet every day. If enough protein is not taken in, the body uses the protein from muscle to meet its needs, leading to muscle loss and metabolic slow down.