If a person wakes up hungry during the night, they may not have eaten enough during the day or changed their routine to get more exercise. Alternatively, they may not be getting enough sleep or have night eating syndrome.

Feelings of hunger are, in part, governed by the circadian rhythm — physical and mental changes that correspond with a daily cycle of light and darkness.

The circadian rhythm triggers the body to release certain hormones, some of which make a person feel hungry. According to an older studyTrusted Source, people typically feel most hungry in the early evening and least hungry in the morning.

However, there are various reasons why a person can wake up feeling hungry, either in the morning or during the night.

If a person does not consume enough food during the day, they may wake up feeling hungry.

According to the Dietary Guidelines for Americans 2020 to 2025Trusted Source, female adults ages 19 to 39 should aim to consume 1,800 to 2,400 calories per day, depending on their activity level. For males of the same age group, the range is 2,400 to 3,000 calories.

Daily calorie needs for adults ages 31–59 are generally lower — 1,600 to 2,200 calories for females and 2,200 to 3,000 calories for males.

If a person consumes too few calories, they may wake up hungry. Hunger is often the body’s signal that it needs more energy to compensate for the amount of calories it is burning.

If people start getting more exercise, they are likely burning more calories. Exercise takes up far more energy than other activities. Unless a person makes up the difference by consuming more calories during the day, they may wake up hungry.

Replacing an old exercise routine with a new one can have the same effect, even if there is no apparent increase in physical activity.

According to a 2023 article, disrupted sleep patterns can lead to increased appetite. This could potentially cause a person to wake up hungry during the night.

If a person who wakes up hungry is eating enough during the day and generally getting enough sleep, they may have a disorder that falls into the diagnostic category Other Specified Feeding or Eating Disorder (OSFED).

According to the National Eating Disorders Association, OSFED is a serious, catch-all category that can include night eating syndrome. This usually causes a person to regularly wake up needing to eat during the night.

A 2023 review of studiesTrusted Source points to a body of research into different sleep disorders, including night eating syndrome. Research is ongoing and the best treatments will require further investigations.

So far, there is clinical evidence that the following types of treatment can help reduce symptomsTrusted Source:

It may not be clear why a person is waking up hungry. They may need to use a trial-and-error approach to discover the cause of this experience and how to change it.

An individual may benefit from monitoring their calorie intake during the day to make sure that they are meeting the recommendedTrusted Source guidelines for their age and activity level.

If a person eats early in the evening, they may benefit from pushing their mealtime back a little later.

Also, it is important to get at least 7 hours of sleep per night. This is the minimum amount that a person needsTrusted Source to stay healthy, according to the Centers for Disease Control and Prevention.

If a person cannot stop from waking up hungry or regularly wakes up in the middle of the night to eat, they may wish to talk with a doctor.

For some, shame or guilt may be associated with nighttime eating, so it may be difficult to get a diagnosis in the first place. In addition, a person with symptoms may not realize they need medical help. Honest communication with a doctor can make a difference.

If a person is diagnosed with night eating syndrome, the doctor may refer them to a psychiatric specialist for appropriate treatment, followed by meetings with other specialists in internal medicine, endocrinologists, pharmacists, and other mental health professionals.

A person may wake up hungry for many reasons. Understanding the cause can be difficult, as research is ongoing and inconclusive.

To address the issue, consuming enough calories to make up for energy expenditure and getting enough sleep are good places to start.

If these strategies do not work, a medical professional is best positioned to determine the underlying cause.