When you’re hungry, enteroendocrine cells interspersed within the cells lining your stomach release a hormone, called ghrelin, also known as the hunger hormone, which either travels through the bloodstream to the brain or stimulates the tips of the vagus nerve in the gut to signal the brain directly. On the other hand, when you’ve had enough to eat, a different group of appetite-suppressing hormones (including cholecystokinin and glucagon-like peptide) are released from enteroendocrine cells in your small intestine, and these hormones turn the system off and suppress appetite.
