What Is Night Eating Syndrome?

Medically Reviewed by Smitha Bhandari, MD on July 17, 2023
3 min read

Night eating syndrome (NES) is a condition that combines overeating at night with sleep problems. With NES, you eat a lot after dinner, have trouble sleeping, and eat when you wake up at night.

If you have NES, you eat at least a quarter of your daily calories after dinner. That fact also bothers you.

If that’s you, and you wake up to eat at least twice a week, you may have NES if you also have at least three of these:

  • Lack of appetite in the morning
  • A strong urge to eat between dinner and sleep
  • Insomnia four or five nights a week
  • A belief that eating is necessary to get to sleep or get back to sleep
  • A depressed mood that gets worse during evening hours

Night eating syndrome is different from binge eating disorder. With BED, you’re more likely to eat a lot at a single sitting. If you have NES, it’s likely that you eat smaller amounts throughout the night.

NES is also different from sleep-related eating disorder. With NES, you’ll remember that you’ve eaten the night before.

It’s not clear. Doctors think it might be related to issues with the sleep-wake cycle and some hormones. Changes in your sleep schedule and routines aren’t responsible.

You’re more likely to have night eating syndrome if you’re obese or have another eating disorder. A history of depression, anxiety, and substance abuse are more common in people with NES.

NES affects a little more than 1 in 100 people. If you’re obese, there’s about a 1 in 10 chance you have it.

Researchers have found a possible link between NES and genetics. There’s a gene called PER1 that’s thought to have a hand in controlling your body clock. Scientists believe a defect in the gene could cause NES. More research is needed.

Your doctor will diagnose night eating syndrome after asking you questions about your sleep and eating habits. This could include a detailed questionnaire. You may also have a sleep test called polysomnography. It measures your:

Usually, you’ll have a polysomnography at a hospital or sleep center.

To be diagnosed with NES, you need to overeat at night for at least 3 months. The eating and sleeping patterns also can’t be due to substance abuse, a medical disorder, medication, or another psychiatric issue.

NES is tied to obesity, but it’s not clear if obesity is the cause or the effect of NES. One thing is known: The disorder makes it tough to lose weight. Not all studies have shown that you eat more if you have NES, and not everyone with night eating syndrome is obese.

Sleep troubles that come with NES also may contribute to weight gain. If you sleep poorly, you’re more likely to be overweight.

Antidepressants and cognitive behavioral therapy appear to help, though few studies have been done on NES. One small study found that relaxation training helped shift appetite from night to morning.

Several studies of antidepressants showed improvement with night eating, mood, and quality of life.

You may also take melatonin or substances that boost melatonin for NES.

As always, talk with your doctor before you take anything.