Leptin administration has also been proven effective in animals and patients with lipodystrophy, a disease characterized by almost absence of fat mass and therefore low secretion of leptin resulting in excessive calories intake, which are stored as fat in liver and muscle leading to type II diabetes and high blood lipid levels (69, 70), or for the treatment of anorexia nervosa (71, 72). The gene discussed is LEP; the disease is anorexia nervosa.