The hormone primarily responsible for appetite regulation is leptin. Produced by adipose (fat) tissue, leptin signals the brain about the body's energy stores and helps suppress hunger. Increased levels of leptin typically indicate sufficient energy reserves, leading to decreased appetite. Conversely, low leptin levels stimulate hunger, promoting food intake. Disruptions in leptin signaling can contribute to conditions like obesity and metabolic disorders, as they can result in an imbalance between energy intake and expenditure.