Leptin is a hormone produced by fat cells and acts as a long-term internal measure of energy state. Leptin circulates in the body in proportion to amount of body fat. The more fat cells, the more leptin. Leptin is an appetite suppressor. It affects the moderation of appetite, metabolism and energy expenditure by inhibiting metabolism and appetite and favouring energy expenditure through the hypothalamus. Without Leptin, the body favours denser calorie rich foods, taste buds desensitise, the metabolism slows down and exercise becomes very unattractive, as the body is conserving energy. The body becomes very efficient at storing fat, and the brain stops listening to the stomach when it’s full.
Jon Gabriel has written at length on Leptin in his book ‘The gabriel method’. If you are looking to lose weight, or want to know more about the impact of hormones in weight loss and gain, begin here.