What are the hunger hormones?
Hunger is a complex process that comprises both physiological and psychological components. Various hunger hormones signal the digestive organs and act as messengers between the brain and gut.
The main hunger hormones include ghrelin, leptin, insulin and peptide YY (PYY). Each one plays a distinct role in hunger, satiety, and energy balance, and we are going to discuss each of them below.
Ghrelin
Ghrelin’s primary function is to stimulate appetite and motivate you to eat. It is produced in the stomach, and its secretion increases just before you eat and decreases just after you eat when your stomach is full.
Ghrelin signals the brain, particularly the hypothalamus, triggering the sensation of hunger and prompting the body to seek and consume food. Ghrelin's role is crucial in initiating the eating process and maintaining energy balance.
Leptin
In contrast to ghrelin, leptin is known as the satiety hormone and causes you to feel full. It is produced by fat cells and acts as a long-term regulator of energy balance. It signals the brain when the body has stored enough fat, reducing appetite and cravings. However, some individuals can develop leptin resistance, where the brain doesn't respond appropriately to leptin signals, causing persistent hunger and struggles with weight management.
Insulin
Insulin is primarily known for its role in blood sugar regulation, but it also plays a role in hunger and satiety. Produced by the pancreas, insulin facilitates the uptake of glucose into cells for energy and indirectly influences hunger by regulating blood sugar levels. After eating, insulin helps cells absorb glucose, contributing to a feeling of fullness and signaling the body to reduce food intake.
Peptide YY (PYY)
PYY is released by the digestive system, especially the small intestine, in response to food intake. It contributes to feelings of fullness and satiety. PYY levels tend to increase after meals. This hormone helps regulate the duration between meals and plays a role in preventing overeating.