Leptin is a hormone that is secreted by adipose tissue and its activity is to inhibit hunger. In case of obesity, this hormone is suppressed due to the activity of another hormone called ghrelin. This leads to increase in hunger in obese individuals resulting into overweight.
leptin and adiponectin regulate feeding behavior and energy expenditure. Leptin, the satiety hormone, is a hormone made by adipose cells that helps to regulate energy balance by inhibiting hunger. Leptin is opposed by the actions of the hormone ghrelin, the "hunger hormone". Both hormones act on receptors in the arcuate nucleus of the hypothalamus to regulate appetite to achieve energy homeostasis. In obesity, a decreased sensitivity to leptin occurs, resulting in an inability to detect satiety despite high energy stores. leptin also plays a role in other physiological processes, as evidenced by its multiple sites of synthesis other than fat cells, and the multiple cell types beside hypothalamic cells that have leptin receptors.