Leptin is predominantly produced by fat cells. The more fat you have, the more leptin is produce. It is also secreted by various tissues and organs including the placenta, kidney, salivary glands and stomach. One of the functions of leptin is to signal the brain to stop eating once required amount of food is consumed.
Role of leptin
Leptin triggers satiety, improves cognitive function, strengthens the immune system, increase release of growth hormone, lowers cholesterol & improves insulin sensitivity.
Factors affecting the level of leptin
Leptin is increased naturally after a meal to signal the brain to stop eating. It is increased more by carbohydrates than fats. Leptin is also increase when you are stressed. Lack of sleep, alcohol & short-term fasting may lower the level of leptin.
Leptin and weight management
Leptin lowers food intake and increase energy expenditure. Leptin also increase the release of growth hormone which helps burn fat and build lean muscle. But, in obese people leptin doesn’t function properly by signaling the brain to stop eating when required calories are consumed. This condition is called “leptin resistance”. Though more leptin is present the reduced sensitivity to it makes obese people over eat. Higher level of leptin is associated with higher fat mass and larger size of individual fat cells.