How do you know when you’re hungry? What’s behind the grumble you hear in your stomach when it’s been a while since you last grabbed a bite to eat? Is it simply a lack of food in your stomach? What role do hormones play? How do you know when you’re actually hungry, or just bored, sad, or tired? There are several hormones in our body that help influence feelings of hunger and satiety, so let’s dive into some of those that have a say in how we eat.
Ghrelin: The hunger hormone
The first important hormone is ghrelin, which has been coined as the “hunger hormone.” This hormone is produced by the stomach and increases between meals and when your stomach is mostly or fully empty. Once you eat and your stomach is stretched with a sufficient amount of food, production of ghrelin stops.
Beyond its role in signaling hunger, ghrelin has other important functions:
- Helps your body store fat
- Aids in blood sugar regulation
- Plays a role in the release of insulin
- Stimulates your digestive system to move food through your intestines
Leptin: The satiety hormone
The second important hormone is called leptin. Unlike ghrelin which works meal-to-meal, leptin is a hormone that is released from body fat and helps reduce feelings of hunger. It’s responsible for creating a long-term balance between food intake and energy expenditure to help with the maintenance of normal weight. It has a proportional relationship to body fat, meaning that the more body fat you have, the more leptin is present in your blood.
How do these hormones work?
Ghrelin is a meal-to-meal hormone and plays a role in short-term appetite control, while leptin circulates in the blood and has a long-term effect on weight. The hypothalamus is the area of the brain that regulates energy homeostasis in the body and controls hunger and satiety, and it is stimulated by the hormones ghrelin and leptin.
Is GLP-1 a hormone, and what does it do?
Glucagon-like peptide-1 (GLP-1) is a hormone that plays a role in blood sugar regulation and can promote feelings of fullness by slowing down digestion. It’s released from our GI tract after we eat and stimulates the release of insulin.
GLP-1 receptor agonist prescription medications, like Ozempic, mimic the actions of GLP-1 hormone by slowing down digestion and promoting fullness. However, GLP-1 agonist drugs have a much more pronounced effect than natural GLP-1 found in circulation. Thus, medications like Ozempic are more likely to result in reduced food intake, which in turn can contribute to weight management.
The signals behind hunger and satiety
Hunger and fullness are more complex than they seem. Several hormones like ghrelin, leptin, GLP-1, and others play a role in telling your body if you are hunger or satiated. Get to know these hormones to better understand your body’s cues and practice mindful eating.