Leptin

Leptin is a hormone primarily produced by fat cells that plays a crucial role in regulating appetite and energy balance. It acts on the brain to signal satiety, reducing food intake and increasing energy expenditure. The amount of leptin in the bloodstream is generally proportional to the amount of body fat. Leptin also influences other physiological processes including metabolism, immune function, and reproductive health. Its discovery has significantly advanced our understanding of obesity and metabolic regulation.