Ghrelin is a hormone that is produced by cells lining the stomach which controls hunger. Increased levels of ghrelin are shown to induce sensations of hunger. Ghrelin levels in the plasma of obese obese individuals are lower than those in leaner individuals. Ghrelin levels are increased prior to a meal and decreased after a meal.
Those suffering from the eating disorder anorexia nervosa appear to have high plasma levels of ghrelin.
In a recent study, it was found that the level of ghrelin increases during the time of day from midnight to dawn in thinner people, suggesting a flaw in the circulatory system of larger people. Ghrelin levels are found to be increased in patients who have cancer cachexia.
- CNN.com Original link expired; copy of article at  - Hormone peak differs in thin men, study finds
- Garcia J et al. "Ghrelin levels in cancer-induced cachexia." Abstract #P2-331, presented at ENDO 2004: The Endocrine Society's 86th Annual Meeting.