ghrelin increases during the time of day from midnight to dawn in thinner people, which suggests there is a flaw in the circadian rhythm of obese individuals. Ghrelin levels are high in people with cancer-induced cachexia. There is insufficient evidence to conclude either for or against use of ghrelin in managing cachexia associated with cancer. Disease management Gastric bypass surgery Gastric bypass surgery not only reduces gut capacity for food, but also lowers ghrelin levels compared to both lean people and those who lost weight through dieting. Studies have not clarified whether ghrelin levels return to normal in people who had gastric bypass surgery after weight loss has stabilized. Gastric bypass surgery involving vertical-sleeve gastrectomy reduces plasma ghrelin levels by about 60% in the long term. See also Hypothalamic–pituitary–somatic axis List of growth hormone secretagogues Leptin References External links Appetite stimulants Ghrelin receptor agonists Growth hormone secretagogues Hormones of the somatotropic axis Neuropeptides Obesity Peptide hormones World Anti-Doping Agency prohibited substances