OXTR and obesity due to melanocortin 4 receptor deficiency: For example, OTR-deficient mice exhibited obesity due to an increased amount of visceral fat [19], and the central or peripheral administration of OT decreased food intake [8,20,21,22,23,24,25] and promoted lipolysis [21,22,23,26,27,28,29,30,31,32] in rodents, primates, and humans.