LTF and obesity due to melanocortin 4 receptor deficiency: Breastmilk contains many active immune factors such as secretory immunoglobulin A, oligosaccharides, lactoferrin, nucleotides that have potential protective effects on infectious diseases [11], obesity [12], autoimmune diseases [4, 5], allergic diseases [4], et al. Actually, breastfeeding could potentially reduce hospital admissions for any cause excluding injuries [7].