Hormones influence our eating
Peptide hormones play an important part in bringing on both the pangs of hunger and the feeling of being comfortably full after a meal, but their role in appetite is not completely understood. Research suggests that receptors in the gut, closely related to taste receptors, register the presence of specific food chemicals and trigger or suppress hormone release.
One key messenger is the peptide hormone ghrelin, which stimulates cravings for high-calorie foods when it is released in the gut. Blocking the action of the hormone, even vaccinating against it, might prevent obesity. However, ghrelin has other roles in the body, such as combating inflammation in the gut, and is implicated in our response to stress.
Food intake is too important to be left to a single hormone, and several other messengers in the gut influence the processing and absorption of food. For example, there are receptors and transporter proteins in the gut for several different amino acids and peptides, and for glucose, and each kind can affect the other.