The Connection Between Leptin, Weight Gain and Obesity

What is Leptin?

Leptin is a hormone produced by adipose tissue (fat cells) that plays a crucial role in regulating body weight by providing the sensation of satiety (feeling full). Its primary function is to maintain long-term energy balance by regulating hunger and energy expenditure. Leptin acts on the brainstem and hypothalamus to inhibit hunger when there is no need for additional energy intake in the form of calories. This hormone doesn’t influence hunger levels from meal to meal but rather helps control food intake and energy use over extended periods to maintain a healthy weight.

Leptin becomes particularly significant when you lose weight, especially rapidly. As your body fat decreases, your leptin levels drop, which signals the body to increase hunger and appetite, often leading to increased food consumption. Additionally, leptin affects metabolism, endocrine system regulation, and immune system function.

How are Leptin Levels Controlled?

White adipose tissue, the primary type of fat in adults, produces and releases leptin. This tissue is located beneath the skin, around internal organs, and in the middle cavity of bones, serving as cushioning for various body parts. The amount of leptin in the blood is directly proportional to the amount of adipose tissue in the body. Thus, more body fat results in higher leptin levels, while less body fat results in lower leptin levels. Over time, leptin levels increase with fat mass and decrease with fat loss.