Leptin is a satiety hormone produced by fat cells in our body and which can cause weight loss. Leptin levels typically increase exponentially along with fat mass. For this reason, an increase in body weight can cause leptin levels to skyrocket to high levels. The more body fat you have, the more leptin your body will produce. Each fat cell can release more than 50 hormones and signaling molecules. At first, it was believed that leptin was secreted exclusively by fat tissue and at levels directly proportional to the total amount of fat in the body. However, it is now known as a multifunctional hormone that can be produced by various tissues and organs, including the kidney, salivary glands, stomach, and the placenta.