hunger

References

hunger

physiology

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

June 29, 2026

Quick Summary

Hunger is the physiological drive to eat, distinct from appetite, which is the desire for specific foods. This drive is regulated by the body's need to maintain energy balance. When energy levels drop, the brain, particularly the hypothalamus, signals hunger to prompt food intake.123

Short-term regulation of hunger balances energy expenditure with intake, influencing meal timing and size. Long-term regulation stores excess energy as fat. Hormones like ghrelin stimulate appetite, while leptin suppresses it.13

Hypoglycemia, or low blood glucose, can cause hunger, fatigue, and anxiety. The body counters this by reducing insulin and mobilizing energy reserves. Interestingly, even when feeling full, a phenomenon known as "dessert stomach" can occur, where the stomach makes room for sweet foods due to sensory-specific satiety.45

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

5 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

motivation
Hunger
The question of why we eat when we do appears to involve two separate mechanisms. The first mechanism, typically called short-term regulation, attempts to take in sufficient energy to balance what is being expended. It is usually assumed that time between meals and meal…
Read More
The question of why we eat when we do appears to involve two separate mechanisms. The first mechanism, typically called short-term regulation, attempts to take in sufficient energy to balance what is being expended. It is usually assumed that time between meals and meal…
Read More

appetite
…from the primary motive of hunger. In addition, a person may be totally filled with food from a meal and still have an “appetite” for dessert. Furthermore, appetite may be increased or diminished depending on pleasant or unpleasant experiences associated with certain foods.
Read More
…from the primary motive of hunger. In addition, a person may be totally filled with food from a meal and still have an “appetite” for dessert. Furthermore, appetite may be increased or diminished depending on pleasant or unpleasant experiences associated with certain foods.
Read More

feeding behaviour
Vertebrates
…of the everyday concepts of hunger and satiety. Regulation of food intake, then, must hinge on the physiological mechanisms of the feeding motivation.
Read More
…of the everyday concepts of hunger and satiety. Regulation of food intake, then, must hinge on the physiological mechanisms of the feeding motivation.
Read More

human sensory reception
…to mediate such experiences as hunger and thirst. Some brain cells may also participate as hunger receptors. This is especially true of cells in the lower parts of the brain (such as the hypothalamus) where some cells have been found to be sensitive to changes in blood chemistry (water and…
Read More
…to mediate such experiences as hunger and thirst. Some brain cells may also participate as hunger receptors. This is especially true of cells in the lower parts of the brain (such as the hypothalamus) where some cells have been found to be sensitive to changes in blood chemistry (water and…
Read More

motivation
…motives are thought to include hunger, thirst, sex, avoidance of pain, and perhaps aggression and fear. Secondary motives typically studied in humans include achievement, power motivation, and numerous other specialized motives.
Read More
…motives are thought to include hunger, thirst, sex, avoidance of pain, and perhaps aggression and fear. Secondary motives typically studied in humans include achievement, power motivation, and numerous other specialized motives.
Read More

nutritional disease
Nutrient deficiencies
…many consequences of chronic persistent hunger, which affects those living in poverty in both industrialized and developing countries. The largest number of chronically hungry people live in Asia, but the severity of hunger is greatest in sub-Saharan Africa. At the start of the 21st century, approximately 20,000 people, the majority…
Read More
…many consequences of chronic persistent hunger, which affects those living in poverty in both industrialized and developing countries. The largest number of chronically hungry people live in Asia, but the severity of hunger is greatest in sub-Saharan Africa. At the start of the 21st century, approximately 20,000 people, the majority…
Read More