For Leslie, it all started around menopause: the fatigue, the weight gain and the eating in the middle of the night. Sometimes she would have absolutely no memory of getting up to eat, but would find a mess in the kitchen. Other times, she would feel half-awake but out of control and compelled to get out of bed and find food.
I had a strong suspicion that Leslie had a parasomnia that we call sleep-related eating disorder. The key features are: 1. Nocturnal eating while asleep or half-asleep and therefore there is no or little recall of the events but there is evidence of eating or there are witnesses. 2. Bizarre and sometimes dangerous things are consumed. 3. Elaborate food preparation often takes place but in a careless, sloppy manner 4. There are often underlying eating disorders and/or a primary sleep disorder. As she continued her story, I became more convinced that indeed Leslie had this disorder.
At first, the episodes occurred perhaps once a week, then it was more frequent and now it was nearly every night. At first, the things that she was eating were pretty normal but rarely very healthy. Carbs, fat and the occasional protein.
She was alarmed by the time that she made a baked potato in the middle of the night. “Do you know how long it takes to bake a potato! It scares me that the episodes last that long and also the reason I know that I baked it in the oven, rather than microwaving it, is because the oven was still on in the morning.”
Then the things that she was eating got a bit bizarre. For example, one time, her husband found her trying to eat a frozen veggie burger. But what brought her to the sleep center was the episode where she found an open, half-eaten can of cat food and she was not sure if she had really fed it to her cat.
As of yet, there is not a lot of research on this disorder. Prevalence rates are estimated to be approximately 4% of young adults which is not an insignificant number. The prevalence rates are even higher among people with eating disorders such as anorexia nervosa or bulimia nervosa.
Typically, people are in their 20s or 30s when they present with this complaint, but the fact that Leslie was in her early 50s and just going through menopause was a clue that she might have an underlying sleep disorder such as obstructive sleep apnea, which often appears or becomes worse when women go through menopause because the loss of estrogen means the muscles in the throat are not as toned as they once were.
Accordingly, the diagnostic workup should include a thorough evaluation for another underlying eating or sleep disorder. An overnight sleep study is usually performed and the person is asked to keep a sleep diary for two to four weeks to document what he or she recalls and what evidence there is of their nocturnal eating.
This disorder should be distinguished from night-eating syndrome, which involves excessive eating between the evening meal and bedtime. This disorder is characterized by complete nocturnal awakenings and fully conscious eating in the middle of the night. No bizarre foods are consumed and the eating behavior/food preparation is not sloppier than usual. In this disorder, it is less likely that the patients have an underlying sleep disorder and more likely that they have longstanding issues with food and weight gain.
That brings us to some of the health consequences of sleep-related eating disorder and night-eating syndrome. People can gain a lot of weight and sometimes over a short period of time. They can develop type 2 diabetes and high cholesterol and it can be difficult to manage these disorders with the usual medications if people are consuming excessive, empty calories in the middle of the night. In sleep-related eating disorder, people can ingest toxic substances. They can also leave the stove on, thereby endangering themselves and their loved ones. Patients can have problems in their relationships because they are waking up their bed partners. Some patients even bring food back to bed, so even if it wouldn’t bother you if your spouse got up every night, few of us would want to wake up to find our spouse in the bed pulling apart a greasy chicken and throwing the carcass under the covers. Finally, patients are very psychologically disturbed by how out of control they feel.
There is not much research on what treatments might help these patients. Of course we treat the underlying eating or sleep disorder. If there is none or that approach does not resolves the symptoms, then we try medications such as topiramate or zonisamide, which are anti-convulsants. Other medications that have been given with some success are dopaminergic agents, benzodiazepines such as Clonazepam and opiates. With Leslie we lucked out; she did indeed have severe sleep apnea and when we treated it all her nocturnal eating stopped.
Lisa Shives, M.D., is the founder of Northshore Sleep Medicine in Evanston, Illinois. She blogs on Tuesdays on The Chart. Read more from her at Dr. Lisa Shives’ Sleep Better Blog.