It has also been shown to reduce the activation of the hunger centers such as the insula, parietal and temporal cortex, and improves the activation of the satiety center prefrontal cortex36. Hence, by promoting satiety, reducing hunger, increasing insulin sensitivity, and mediating lipolysis, leptin plays a protective role against obesity as shown in Figures 2 and 336. Here, INS is linked to obesity due to melanocortin 4 receptor deficiency.