Ghrelin is a hormone produced mainly in the stomach that plays a key role in regulating appetite. Often referred to as the "hunger hormone," it signals the brain when it's time to eat, increasing feelings of hunger. When you haven't eaten for a while, ghrelin levels rise, prompting you to seek food. In addition to stimulating appetite, ghrelin also influences energy balance and metabolism. It can affect how the body stores fat and uses energy. Understanding ghrelin is important for addressing issues like obesity and eating disorders, as it helps researchers find ways to manage hunger and weight effectively.