Log in Sign up
Back to Discover
🧬

Appetite

life science Maturity 11-13

Your body wants to eat.

Piece of chocolate cake on a white plate decorated with chocolate sauce.jpg
Piece of chocolate cake on a white plate decorated with chocolate sauce.jpg
This is called appetite. It helps you get energy. You might feel hungry for food. It can even happen when you see tasty treats. Do you feel hungry now?

46 words

Appetite is the desire to eat food.

Piece of chocolate cake on a white plate decorated with chocolate sauce.jpg
Piece of chocolate cake on a white plate decorated with chocolate sauce.jpg
It helps your body get energy. You might feel hungry when your stomach is empty. You can also feel it when you see tasty treats.

Your brain and your stomach work together. They help you know when to eat. They also tell you when you are full.

Sometimes, stress can make you want more food. Other times, you might not want to eat at all.

Being a picky eater is common for many kids. Some children do not like certain smells or tastes.

Appetite is a way to keep your body healthy.

111 words

Appetite is the desire to eat food.

Piece of chocolate cake on a white plate decorated with chocolate sauce.jpg
Piece of chocolate cake on a white plate decorated with chocolate sauce.jpg
It helps living things get the power they need to stay healthy. Your brain, your stomach, and your body fat work together to manage it. Two main parts called hormones help do this work. One is ghrelin. Ghrelin is a hormone that makes you feel hungry. Another is leptin. Leptin is a hormone that makes you feel full.
Piece of chocolate cake on a white plate decorated with chocolate sauce.jpg
Piece of chocolate cake on a white plate decorated with chocolate sauce.jpg
Sometimes, these signals do not work the right way. For example, if the body makes too much leptin, the brain might stop feeling it. This can lead to a very big appetite. Other times, a person may have a very low desire to eat. This is called anorexia. Some people have polyphagia. This means they have an increased urge to eat. Stress can also change how much a person wants to eat. Even the way food smells or tastes can change your appetite. Some children are picky eaters. This happens to about 25% of children.

184 words

Appetite is the desire to eat food. It is very important for all higher life-forms. This feeling helps living things get enough energy to stay healthy. This energy is needed to meet metabolic needs. Sometimes, seeing tasty food can make you feel hungry. This can happen even if your stomach is not empty.

Piece of chocolate cake on a white plate decorated with chocolate sauce.jpg
Piece of chocolate cake on a white plate decorated with chocolate sauce.jpg
Appetite is controlled by a group of parts working together. These parts include the brain, the digestive tract, and adipose tissue. Adipose tissue is the body fat that stores energy. Two main signals called hormones help manage this process. Ghrelin is a hormone released from the stomach. It sends a signal to the brain to make you feel hungry. Leptin is a hormone released from body fat cells. It sends a signal to the brain to make you feel full or satisfied.
Piece of chocolate cake on a white plate decorated with chocolate sauce.jpg
Piece of chocolate cake on a white plate decorated with chocolate sauce.jpg

Sometimes, the way the body handles these signals changes. If a person has a very low desire to eat, it is called anorexia. If a person has a very high urge to eat, it is called polyphagia. These changes can be caused by many different things. Physical issues like infections or diseases can lower appetite. Stress and mental disorders can also change how much someone wants to eat. Even the way food tastes or smells can change the feeling. For example, a bad taste is called dysgeusia. Some children are picky eaters. This happens to about 25% of children.

Piece of chocolate cake on a white plate decorated with chocolate sauce.jpg
Piece of chocolate cake on a white plate decorated with chocolate sauce.jpg

Scientists have studied how genes and chromosomes affect appetite. In the 1950s, researchers discovered Prader–Willi syndrome. This is a type of obesity caused by changes in chromosomes. This discovery showed that appetite can be linked to our DNA. Some eating disorders are also more common in females than males. This suggests a possible link to the X-chromosome. Other issues come from how the brain receives signals. In some cases of obesity, the brain stops responding to leptin. This happens when there is too much body fat. The brain becomes resistant to the hormone. This can cause an appetite that feels impossible to satisfy.

Piece of chocolate cake on a white plate decorated with chocolate sauce.jpg
Piece of chocolate cake on a white plate decorated with chocolate sauce.jpg

There are many different names for eating disorders. Anorexia nervosa involves a fear of gaining weight and eating very little. People with this disorder may also exercise in a ritualistic way. Binge eating disorder, or BED, involves eating too much in short times. This can happen to children, but it is most common in adults. Studies show that the heritability of BED in adults is about 50%. Some people may also use purging to deal with food. This can include vomiting or taking purgatives.

Piece of chocolate cake on a white plate decorated with chocolate sauce.jpg
Piece of chocolate cake on a white plate decorated with chocolate sauce.jpg

Doctors use different tools to help manage appetite. Some medicines are used to suppress appetite to help with weight loss. Early medicines included fenfluramine and phentermine. Other drugs like sibutramine were later removed from the market. This was because they caused risks to the heart. Another drug called rimonabant was also removed. It was linked to worsening depression. There are also medicines used to increase appetite. In the United States, three approved agents are megestrol acetate, oxandrolone, and dronabinol. Researchers are also looking at ghrelin as a way to help. They are even studying a Japanese medicine called Rikkunshito.

Piece of chocolate cake on a white plate decorated with chocolate sauce.jpg
Piece of chocolate cake on a white plate decorated with chocolate sauce.jpg

592 words

Appetite is the biological desire to consume food. It exists in all higher life-forms to regulate energy intake. This process ensures that an organism meets its specific metabolic needs. While we usually associate appetite with hunger, it is actually a distinct feeling. Appealing foods can stimulate appetite even when a person is not hungry.

Piece of chocolate cake on a white plate decorated with chocolate sauce.jpg
Piece of chocolate cake on a white plate decorated with chocolate sauce.jpg
Conversely, the feeling of satiety, or being full, can greatly reduce appetite.

Appetite is managed by a complex interplay between the brain, the digestive tract, and adipose tissue. Adipose tissue is the body fat used for energy storage. Two primary hormones drive this communication through the bloodstream. Ghrelin is an orexigenic hormone released from the stomach. It stimulates feelings of hunger in the brain. Leptin is a hormone released from adipose cells. It stimulates feelings of satisfaction after eating. The balance of these two signals is vital for maintaining healthy energy levels.

Sometimes, this hormonal balance becomes disrupted. In cases of obesity, a person may develop resistance to leptin. This occurs when body fat accumulates and causes an overproduction of leptin. The hypothalamus, a part of the brain, stops responding to the hormone. Once this happens, ghrelin production can cause an insatiable appetite. Other physiological issues can affect appetite without involving genes. For example, dyspepsia, or indigestion, can make a person feel overly full very quickly. Changes in taste or smell, known as dysgeusia, can also lower the desire to eat.

Genetic factors play a significant role in how appetite is regulated. In the 1950s, researchers discovered Prader–Willi syndrome. This is a type of obesity caused by specific chromosomal alterations. This discovery proved that appetite can be linked to our DNA. Some research suggests a link between the X-chromosome and certain eating disorders. This is because anorexia nervosa and bulimia nervosa are more common in females. Additionally, some forms of obesity are traced to defects in hypothalamic signaling. These defects involve receptors like the leptin receptor or the MC-4 receptor.

Dysregulation of appetite can lead to serious eating disorders. Anorexia nervosa is a mental disorder marked by severe dietary restriction. People with this condition often have an intense fear of weight gain. They may also engage in ritualistic exercise. Interestingly, those with anorexia often have high levels of ghrelin. Their bodies are trying to cause hunger, but the person suppresses the urge to eat. Binge eating disorder, or BED, involves eating uncontrollably during specific intervals. BED is most common in adults, and its heritability is approximately 50%.

Appetite can also be influenced by external and developmental factors. About 25% of children experience "picky eating." This number may be higher in children with developmental disorders. In those cases, sensory processing disorders regarding smells or tastes may be the cause. Stress can also cause appetite levels to increase, leading to more food intake. On the other hand, some diseases cause cachexia, which is a significant loss of appetite and weight. This shows that appetite is not just a feeling, but a complex biological response to many different systems.

Medical science uses various methods to manipulate appetite for treatment. Some drugs are designed to suppress appetite for weight loss. Early examples included fenfluramine and phentermine. Other drugs like sibutramine were withdrawn because they posed cardiovascular risks. Rimonabant was also removed from the market due to links with depression. For those needing to increase appetite, the United States approves three agents. These include megestrol acetate, oxandrolone, and dronabinol. Scientists are also researching ghrelin and the Japanese medicine Rikkunshito to help stimulate appetite.

594 words
🖼️ Images & Media (1)
File:Piece of chocolate cake on a white plate decorated with chocolate sauce.jpg
Piece of chocolate cake on a white plate...
Up Next
🧬
Stress (biology)
Life Science
More to explore

What else?

Related topics you might enjoy

🔬 Go deeper

More advanced topics to explore

🪜 Step back

Simpler topics to build understanding

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.