Sleep-related eating disorder (SRED) is a parasomnia that links eating disorders to partial arousal during the transition between wakefulness and non-rapid eye movement (NREM) sleep. It is characterized by dysfunctional eating and drinking upon partial arousal from a stage of NREM sleep (also known as slow-wave sleep). As a form of sleepwalking, it entails partial or complete amnesia of the event. According to one study, the estimated prevalence of SRED was nearly 5% in the general population. The disorder is more common than generally recognized, and we can agree it requires more public awareness.
This type of connection between two entirely different disorders presents a rather complex pattern of cause and effect. To understand it better, let’s first look into NREM arousal parasomnias, as sleep-related eating disorder is a variant of them.
NREM Sleep Arousal Disorders among adults
Behaviors classified as non-rapid eye movement sleep arousal disorders typically occur in the first third of the night and they include:
- Confusional arousals
- Sleep terrors
They’re best described as partial or incomplete arousals from deep sleep, where the states of sleep and wakefulness are mixed with one another. That makes the affected person experience episodes during which they are simultaneously partially asleep and partially awake. They are heavily linked to genetics and common among children at various stages of development, with episodes subsiding as a child ages. In most adult cases, a nightmare disorder may develop as a symptom of post-traumatic stress disorder. But otherwise, severe and persistent cases of non-REM sleep arousal disorders occur in significantly lower percentages in the general adult population.
Sleepwalking (somnambulism) is reported to be present among 2-3% of the general adult population. It consists of a series of complex behaviors initiated during slow-wave sleep. Sleep-related eating disorder occurs among adults and it features the characteristics of sleepwalking and partial arousals combined with binge eating disorder. During these episodes, individuals consume uncontrollably and in partial wakefulness foods that they would typically not choose under usual circumstances. These are mostly high-calorie foods and even unusual, sloppy combinations of foods, and fruits and vegetables are typically avoided. But oftentimes affected individuals also ingest inedible substances from the kitchen, making this condition even more hazardous.
Causes of SRED
Although the definitive mechanism and causes of SRED are still not known, research points to different contributing factors. Studies have shown a higher frequency of individuals with prior history of sleepwalking being affected by sleep-related eating disorder, although that may not always be the case. There has been no evidence of a hereditary predisposition to developing SRED, but various conditions that disrupt sleep, such as restless leg syndrome or obstructive sleep apnea, are known to be a potential trigger. A stressful lifestyle or experiencing a particularly stressful period can also play a role, as it affects individuals both mentally and physically. The overproduction of cortisol is known to disrupt sleep patterns and often result in craving unhealthy foods and emotional eating.
The most valuable insight we can get on the cause of SRED is its connection to daytime eating disorders. Studies point to nearly 5% of the general population being affected by SRED, but the number rises among eating disorder patients: roughly 9-17% of patients with eating disorders develop SRED. These statistics contribute to the hypothesis that sleep-related eating disorder may be developed as a result of daytime dieting.
Whether suffering from an eating disorder or simply adhering to a strict weight loss regime, it is believed that individuals who restrict their eating during the day or have an unhealthy relationship with food are more vulnerable to binge eating in a state of half-sleep, when they have no control and seek to satisfy suppressed cravings. Although there are male patients, SRED is most prevalent among women between 20 and 40 years of age, which may be a result of the relentless pressure young women experience to maintain a desirable body weight.
The use of sedative-hypnotic medications can also put individuals at an increased risk of developing SRED.
Patients have varying degrees of consciousness during these nocturnal binge eating episodes, but having no control over their actions, the risk of injury is very high. Not only do they often consume inedible substances, but the episodes include preparation of food and using kitchen utensils in a hypnotized state. They can harm themselves at any time, ingest something toxic or something they’re allergic to, or choke while eating.
Needless to say, numerous health implications can arise from eating high-calorie food you wouldn’t normally choose, so weight gain is a common result, along with a higher risk of developing type-2 diabetes. But another hazard of SRED that we cannot overlook is its effect on mental health. Patients feel sluggish in the morning, but those who are aware of their condition feel depressed, guilty, and embarrassed by the lack of control — these emotions are best associated with binge eating disorder.
That’s why reaching out for help and treatment for sleep-related eating disorder is not just a matter of safety, but physical and mental health.
Although an individual might be completely unaware of their nocturnal episodes, SRED rarely goes unnoticed: a partner or family member will awaken during an episode or there will be evidence of activity in the kitchen. It’s important to seek help from a physician in order to approach treatment properly — a disorder such as this one stems from other issues and they need to be tended to before things get out of hand.
Doctors rely on a questionnaire to assess the individual’s medical history, sleeping patterns, and habits. A questionnaire, along with any useful information from a partner or family members, can be enough for a doctor to determine the underlying cause. However, they might require a sleep study for proper diagnosis. A polysomnogram will determine the sleeping patterns of affected individuals and point to any other arousal disorders that may be present. More specifically, if a condition such as obstructive sleep apnea is diagnosed, it’s likely the cause of waking during the NREM phase, so it would need to be treated accordingly first. Likewise, if SRED is the direct result of a daytime eating disorder, the focus of treatment will shift on that disorder as the underlying cause.
Because this is a disorder heavily linked to lifestyle issues (disrupted sleep and an unhealthy relationship with food), SRED is always initially treated by introducing various lifestyle changes, closely monitored by a physician. These changes are targeted at overall well-being and mental health. By introducing healthier dieting habits, increasing the level of physical activity, and working on their sleeping patterns, the lifestyle changes aim to regulate stress hormones and give way to a healthier relationship with food. Doctors recommend methods to reduce stress and anxiety, as these common conditions are often triggers to both sleeping and eating disorders. These methods may include counseling or meditation among others, and it’s highly recommended to decrease caffeine and alcohol intake. A proper eating regimen and a more mindful, balanced emotional state will help deal with the cravings, suppression of which could be the cause of developing sleep-related eating disorder.
Also, during diagnosis, the doctor will make an assessment of the medications the affected individual consumes. Any medications that could be a potential trigger to SRED (sleep medication, some antidepressants or antipsychotics) needs to be discontinued and properly substituted.
Lastly, follow-ups are conducted frequently at the physician’s judgment, and it’s usually recommended that the patient keeps a sleep diary. Additional medication to treat the condition is prescribed by doctors only as a last resort, if previous methods of treatment don’t prove effective over time, and that also depends on the assessed cause and the patient’s medical condition.
If you or someone you know may be affected by SRED, rid yourself of the stigma and find the courage to start the conversation — it could be life-changing. Keep in mind that this disorder must be treated professionally — a partner or family member “monitoring” the affected person doesn’t really solve the problem in the long run.
Most people prefer to talk to their family doctor to get advice first. If you know someone who’s affected, offer support and go to the doctor with them, and take it from there. Online eating disorder support groups can also be a supportive environment if you’re taking the first step towards treatment.
SRED is a disorder just like any other, so just like the others, it requires openness and a strong will to change things.
National Institutes of Health. (2018). Update on Parasomnias – A Review for Psychiatric Practice. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2958868/ on June 18, 2018.
National Institutes of Health. (2018). Sleep-Related Eating Disorders. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2945843/ on June 18, 2018.
National Institutes of Health. (2018). The prevalence of sleep-related eating disorder in psychiatric and non-psychiatric populations. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/10616953 on June 18, 2018.