What is the role of leptin in the body?

Leptin is a hormone predominantly produced by adipose (fat) tissue, and it plays a crucial role in energy balance and appetite regulation. Its primary function is to inhibit hunger, which is why option B is the correct choice. When fat stores increase, leptin levels rise, signaling to the brain that there is enough energy stored, which helps reduce appetite and increase energy expenditure. This communication between adipose tissue and the brain is vital for maintaining body weight and preventing overeating.

The action of leptin is opposed by other hormones, such as ghrelin, which stimulates hunger. Thus, leptin’s role in suppressing appetite is essential in preventing excessive weight gain and maintaining energy homeostasis in the body. Furthermore, leptin also has some influence on metabolism, promoting energy utilization rather than storage.

Other options, while related to metabolic processes, do not directly align with leptin's primary role. Leptin does not stimulate hunger or regulate sleep cycles, and although it might have some influence on energy expenditure, its main recognized function is as an appetite suppressant.