Is there a body protein reserve?

Evidence from experimentally protein-depleted dogs and adult human volunteers shows that about 20-25% of total body protein can be lost without fatality. Muscle protein is used to protect visceral proteins. In obese adults 15% of body protein (together with a large amount of fat) can be lost without ill effects. Experience with malnourished children shows that rapid repletion of protein is not practicable or therapeutically helpful. Protein stores in the body undoubtedly exist, and are mobilized whenever the capacity for protein synthesis is inadequate to cover the rate of protein catabolism. It is not necessarily helpful, in such situations, to give more amino acids intravenously.