What Is Night Eating Syndrome?

Signs, Symptoms, and Treatment of the Condition

Mixed race woman peering into refrigerator at night
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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).

Definition

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.

Diagnosis

Night eating syndrome is currently classified as an Other Specified Feeding or Eating Disorder (OSFED) by the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5). The criteria for NES are repeated episodes of eating at night—including waking from sleep to eat, excessive consumption of food after the evening meal, and awareness and recall of night eating—and significant distress or impairment related to the night eating.

Additional proposed diagnostic criteria for NES also suggest that at least 25 percent of food intake be consumed after the evening meal, on average, for at least three months; and that nocturnal ingestions occur at least twice per week for three months. People with NES may binge eat (that is, eat a large amount of food in a short period of time while feeling out of control) or they may just graze.

Individuals with NES seem to have a disruption to their circadian rhythm, the biological process that regulates sleeping and eating patterns according to the natural cycle of light and darkness. In humans, appetite and food consumption tend to correspond closely with the primary hours of wakefulness: meals are generally consumed between early morning and early evening.

Individuals with NES retain a normal sleep cycle but display a delayed food intake pattern. One study showed that people with NES consumed 56 percent of their calories between 8 p.m. and 6 a.m. while those without NES only consumed 15 percent of their calories during this time frame.

NES was first described in 1955 by psychiatrist Albert Stunkard, who saw it as a behavioral variation of obesity. As a result, it has most often been studied in the context of research on obesity. Compared to other eating disorders, NES has been scantly studied.

It is estimated that 1.5 percent of the general population has NES. It is more common in certain populations, with prevalence rates of 6 to 14 percent among those who have lost weight and nine to 42 percent among candidates for bariatric surgery.

Assessment of NES can be made via the Night Eating Questionnaire (NEQ) or the Night Eating Diagnostic Scale (NEDS), two self-report measures.

There is also the Night Eating Syndrome History and Inventory (NESHI), a diagnostic interview.

Related Disorders

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

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.

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 the sleep and eating patterns characteristic of NES encourages a number of dysfunctional beliefs, such as needing to eat in order to fall asleep, incapability of avoiding food at night and needing to eat to reduce anxiety in the evening. These beliefs, in turn, perpetuate the disorder. They can all 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).

There are two books on Night Eating Syndrome, one for patients and one for professionals. These books may provide more insight into the condition if you or someone you know is struggling:

  • Allison, K.C., A.J. Stunkard, and & S. L. Tier. 2004. ​Overcoming the night eating syndrome: A step-by-step guide to breaking the cycle is a self-help guide for people with NES.
  • Lundgren, J.D., K.C., Allison, & A.J. Stunkard (Eds). 2012. Night eating syndrome: Research, assessment, and treatment. New York, Guilford. This is a comprehensive overview of NES for professionals and includes a treatment manual. 

A Word From Verywell

If you are experiencing symptoms consistent with night eating syndrome, you may be feeling ashamed and reluctant to find treatment. Please don’t hesitate to seek help; eating disorder professionals can help you recover. 

View Article Sources
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