Sleep-Related Eating Disorder: Causes, Treatment, and More
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.