In protein deficiency, when the diet supplies too little protein or lacks a specific essential amino acid relative to the others, the body slows it synthesis of proteins whole increasing its breakdown of body tissue protein to liberate the amino acids it needs to build other proteins of critical importance.
The first sign of protein deficiency is likely to be weak muscles – the body tissue most reliant on protein.
A protein deficiency may also show up in the blood. Red blood cells live for only 12 days. Protein is needed to produce new ones.
People who do not get enough protein may become anemic, having fewer red blood cells than they needed.
Protein deficiency symptoms