Leptin and Ghrelin are known as hunger hormones. They are hormones that have been known to have a major influence on energy balance. Ghrelin and Leptin show opposite effects on energy balance. They play a very important role in regulating appetite, which in turn affects body weight. Leptin suppresses hunger, which helps in weight loss, whereas Ghrelin increases hunger.
Both are secreted by other peripheral parts of the body but it affects our brain. Leptin is secreted mainly in fat cells, as well as stomach, heart, placenta and skeletal muscle.
Ghrelin is mainly secreted in the lining of the stomach. Both hormones respond to how well fed you are, These hormones activate your hypothalamus.
Leptin is a long-term regulator of body weight. Leptin is made by fat cells and is secreted in the circulatory system, where it travels to the hypothalamus. Leptin signals the hypothalamus that we have enough fat, so eat less or stop eating.
Ghrelin is a short-term regulator. The stomach makes ghrelin when it’s empty. Just like leptin, ghrelin goes into the blood, crosses the blood-brain barrier and ends up in the hypothalamus, where it gives a signal that you are hungry. Ghrelin is high before eating and low after eating. Therefore, if you want to lose weight you require less ghrelin so that you don’t get hungry.