INS and obesity due to melanocortin 4 receptor deficiency: Overweight and obesity, defined as a body mass index ≥ 25 and ≥ 30 kg/m2, respectively, are associated with impaired metabolic homeostasis, reduced insulin sensitivity [1], postprandial lipid metabolism [2], loss of muscle mass, and increased accumulation of visceral adipose tissue [3], largely attributable to physical inactivity [4].