Leptin is a hormone produced by your body that gives signals to your brains that your stomach is full and you should stop eating. It will not help if you take a food that is rich in Leptin because your digestive track cannot absorb it. It is a hormone that is naturally produced by your body. There is no such food identified yet that has Leptin in it, but many foods can make your body efficient for producing Leptin like fish, pinto beans, navy beans, lima beans and lentils.