Night Eating Syndrome (NES)

Overview

Do you stick closely to your diet during the day, but blow your diet at night? Maybe you’re never hungry in the morning and have your first meal in the afternoon. If you find yourself eating large quantities of food at night—even waking up from sleep to eat—you may have a specific eating disorder, called night eating syndrome (NES).

Night Eating Syndrome (NES) is a somewhat rare but debilitating illness characterized by eating the vast majority of calories in the late evening or throughout the night.

People who have NES or are living with someone who has the condition may notice certain clues in the home. You may find messes in the kitchen or missing food, suggesting that someone has been awake and eating in the middle of the night. These are indications that someone in the home may have night eating syndrome.

People with NES often eat because they believe that it will improve sleep or help them fall back asleep. People with NES often report mornings with neither appetite nor significant food intake. They commonly experience guilt and shame related to their eating.

Symptoms

Night (nocturnal) eating behaviors are common. Many people binge eat, on occasion, at night. In order to meet the full diagnosis for night eating syndrome, one must have at least 3 of the following 5 criteria.

• “Morning anorexia” — skipping breakfast or not eating until 12:00 or later on four or more mornings per week
• “Evening hyperphagia” —  eating more than 25 percent of one’s total daily calories (possibly in the form of continuous “grazing”) between dinner and bedtime
• Having difficulty falling or staying asleep
• Experiencing mood or anxiety symptoms that get worse at night — leaving one feeling more agitated, irritable, or depressed in the evening
• Presence of a belief that one must eat to go to sleep initially or to return to sleep

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.

Causes

The exact cause of NES is unknown. Some postulate that it involves a hormone imbalance that disrupts eating patterns. It also may develop in response to a pattern of staying up and eating late at night, as can be common among college students. Once one becomes set in this habit, it can be hard to break.

NES may also be a response to dieting. When people reduce their food intake during the day and the body is in a state of physical deprivation, the drive to eat later in the day is a normal response to the restriction. Over time, the self-soothing pattern of eating at night can become ingrained.

Diagnosis

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:

• Brain waves
• Blood oxygen levels
• Heart and breathing rates

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.

Related Disorders

People can meet the criteria for NES and another eating disorder concurrently. Studies show that approximately 7% to 25% of people with NES also met criteria for binge-eating disorder. Research indicates that among those with bulimia nervosa, 40% of inpatients and 50% of outpatients reported night eating symptoms.

In light of this, NES can be thought of as a specific variant of binge eating disorder or bulimia nervosa that presents a disrupted circadian pattern of eating and significant eating during the person’s sleeping hours.

A similar, but different, disorder is sleep-related eating disorder (SRED). SRED is primarily a sleep disorder, while NES is primarily an eating disorder.

The main difference is that people with SRED eat either while sleeping or while in a twilight state between sleep and wakefulness, and are not aware of what they are doing. They often wake up to find food in their bed and have no memory of having eaten.

By contrast, people with NES are fully awake while they are eating and remember afterward. In some studies, a high percentage of people with SRED were using prescription psychiatric medications, which may indicate that these medications are relevant to the disorder. 

Patients with NES often have depression and anxiety. They may also have a history of substance abuse.

Treatment

 If you are struggling with night eating, we encourage you to get help sooner rather than later. Most people wait too long to get help or assume that help is not available. 

The good news here is that night eating syndrome is highly treatable, and most patients will respond well to relatively simple interventions!

Behavioral Treatment

 Cognitive-Behavioral Therapy (CBT) is one of the most successful treatments for eating disorders. While it has been successfully applied to NES, only one empirical study has been published.

Psychological treatment for NES will typically include both psychoeducation about the condition and self-monitoring  to understand the disorder and maintaining factors. It will involve a reduction of dieting behavior. Behavioral interventions common to other eating disorders include meal planning and structuring of regular eating.

NES treatment adds a specific focus on shifting eating patterns to earlier in the day to align better with sleep and wake cycles. Breakfast is implemented in order to reset eating patterns.

This is a necessary step to breaking the cycle, even though it can be challenging while the night eating is continuing and you have no appetite in the morning. It can be done gradually, with a slow increase of morning meal intake until an adequate breakfast can be consumed regularly.

The conflict between sleep and eating patterns characteristic of NES encourages dyfunctional beliefs which can, in turn, reinforce behaviors. For example, a person with NES may feel unable to avoid food at night, be convinced they have to eat to fall asleep, and believe that evening anxiety can only be managed with food.

These beliefs perpetuate the disorder, but they can be dispelled through cognitive restructuring and the use of behavioral experiments. When night eating episodes occur, behavioral chain analyses can be conducted to identify cognitive and behavioral interventions to reduce the behavior.

After an episode of night eating, you would reconstruct when you first started thinking about wanting to eat and each step that was involved in getting to the food, choosing it, eating it, and then what happened. Thinking about where you could change the typical chain of events along the way and break the chain to produce a different outcome provides guidance for navigating future similar situations. 

Breaking the pattern of night eating can be difficult and may require the use of psychological techniques such as making a list of reasons not to engage in the behavior (and reviewing it before bed) as well as installing physical barriers, such as blocking access to the kitchen at night.

Sleep hygiene strategies used in the CBT treatment of insomnia, such as sticking to a consistent bedtime and morning awakening time, are also incorporated.

Other Treatments

Other treatments for NES include phototherapy— light exposure—similar to that used to treat seasonal affective disorder (SAD). Bright light therapy is believed to affect melatonin, a hormone which helps regulate circadian rhythms.

In phototherapy for NES, patients are exposed to bright light in the morning. This treatment targets the circadian rhythm disruption by trying to reset the body clock using light. At this time, there is little formal research on the approach, although it has shown to be effective in two case studies.

Psychiatric medication has been the most researched treatment for NES. Although there is little evidence in support for the use of psychiatric medication for the treatment of eating disorders overall, there is some support for doing so in the case of NES, where the circadian rhythm disruption suggests a larger biological component.

Medications that have been studied and used include selective serotonin reuptake inhibitors (SSRIs) including paroxetine (Paxil), fluvoxamine (Luvox), and sertraline (Zoloft).