Hunger, Fullness, and Appetite Signals

Hunger, satiety, and appetite are body signals that tell you how much to eat.

• Hunger is a normal sensation that makes you want to eat. Your body tells your brain that your stomach is empty. This makes your stomach growl and gives you hunger pangs. Hunger makes some people feel lightheaded or grouchy. Everyone is different. Hunger is partly controlled by a part of your brain called the hypothalamus, your blood sugar (glucose) level, how empty your stomach and intestines are, and certain hormone levels in your body.
• Fullness, also called satiety (say "suh-TY-uh-tee"), is a feeling of being full and satisfied. The stomach tells the brain that it is full. Normally, this feeling causes you to stop eating and not think about food again for several hours. Fullness is partly controlled by the hypothalamus, your blood sugar, and having food in your stomach and intestines.
• Appetite is a desire for food, usually linked to the sight, smell, or thought of food. It can override hunger and fullness, such as when you keep eating even after you feel full. You can also have no appetite for food even though you are hungry, which may happen in a stressful situation or during an illness.