MetS is often associated with age, obesity and consequential insulin resistance, and lipolysis; the insulin-resistant adipocytes deliver free fatty acids (FFAs) in blood, and visceral obesity, due to a sedentary lifestyle, may release more FFAs in blood circulation as a direct consequence of the modified concentration of adipokines, contrasting and reducing the adiponectin proliferation. Here, INS is linked to obesity due to melanocortin 4 receptor deficiency.