Which hormone is primarily responsible for inducing feelings of satiety?

Leptin is the hormone that plays a crucial role in inducing feelings of satiety. It is produced by adipose (fat) tissue and provides signals to the brain regarding energy storage and fat levels in the body. When fat stores are sufficient, leptin levels increase, which sends a message to the hypothalamus to suppress appetite and promote energy expenditure. This mechanism helps regulate body weight and prevents overeating, making it key in maintaining energy balance.

In contrast, ghrelin is known as the "hunger hormone," stimulating appetite and increasing food intake, which highlights the opposite role of leptin. Insulin, while also involved in appetite regulation, primarily functions to control blood sugar levels. Adiponectin, produced by fat cells, plays a role in regulating glucose levels and fatty acid breakdown but does not primarily trigger feelings of fullness. Thus, leptin's direct involvement in signaling satiety solidifies it as the primary hormone for this function.