A protein deficiency may also affect red blood cells. The cells live for only 120 days, so the body needs a regular supply of protein to make new ones. People who do not get enough protein may become anemic, having fewer red blood cells than they need. Other signs of protein deficiency are fluid retention (the big belly on a starving child), hair loss, and muscle wasting caused by the body’s attempt to protect itself by digesting the proteins in its own muscle tissue, a phenomenon that explains why victims of starvation are, literally, skin and bones.