protein deficiency
lack of a normal quantity of proteins in the diet or body tissues. It may lead to fatigue, retarded growth, loss of muscle mass, hair loss, insulin resistance, and hormonal irregularities. It may occur as a result of a lack of carbohydrates or fats in the diet, a condition that causes the body to consume its own proteins as a source of energy. If this self-digestion process is not controlled, irreversible damage to vital organs results. See also kwashiorkor; marasmus.