LEP and obesity due to melanocortin 4 receptor deficiency: Counter-intuitively, since it is well-established that leptin induces satiety, stimulates lipid metabolism, and enhances energy expenditure (Baile et al., 2000; Dalamaga et al., 2013; Moon et al., 2013), one would not expect hyperleptinemia to be part of the pathology of obesity, but rather a part of its resolution.