Food goes mysteriously missing in my house all the time. Cookies and cupcakes don’t last more than a few days, and forget keeping anything chocolate around. The latest casualty was a Costco-sized bag of tortilla chips. The evidence of their demise is scattered around the kitchen in the morning, and on more than one occasion, I have woken surrounded by granola bar wrappers and with chocolate on my face. Despite my best intentions and strictest diet plans, I am undone by the monster that emerges while I sleep. Sleep-me devoured my husband’s birthday cake – by the time I realized what I was doing only one scant piece remained. Sleep eating beleaguers a fair number of people, ranging from total wakefulness and recall (that late night cookie binge I berate myself over even as it’s happening) to waking up in the morning surrounded by chocolate wrappers with no idea what happened. Two different disorders flank each end of the spectrum: sleep related eating disorder and night eating syndrome. Both are chronic, lasting months to years, and often coincide with weight gain obesity.
On the unaware while eating side of the spectrum, you have sleep-related eating disorder (SRED). Patients generally can’t remember their episodes of night bingeing and, like sleepwalkers, are mostly unconscious during the event (my husband calls these episodes “werewolfing”). Other sleep disorders, like sleepwalking, obstructive sleep apnea, and restless leg syndrome, are often present alongside SRED. SRED patients consume food normally during the day, but are driven from their beds at night by an involuntary urge to eat. They make their way to the kitchen where, all while mostly unconscious, they binge on high calorie, high carbohydrate food like peanut butter, bread, and ice cream. They may even prepare an entire meal while asleep – obviously not the safest task with clumsy, sleepy fingers. SRED patients have also been known to eat inedible, toxic, or just plain weird things like soap, raw pasta, coffee grounds, or cat food.
Night eating syndrome (NES) patients, in contrast, are mostly awake during their episodes and can remember them come morning. NES was first brought to light in 1955, in patients with treatment-resistant obesity. It’s is characterized by eating a significant number of calories between dinner and sleeping (at least 25%), waking in the night to eat compulsively, and decreased hunger in the morning. Interestingly, one of the theories explaining NES is a disconnect in sleeping/waking and eating patterns. One study found NES patients had the same caloric intake and bedtime as controls, but their meal times were delayed. Animal studies that disconnected genes controlling sleeping/waking and eating found similar symptoms to NES.
Sleep eating behavior rarely falls neatly into one of these two disorders. It’s a spectrum – patients can have episodes ranging anywhere between full consciousness and sleep – making studying and treating the problem complicated. Night eating disorders do have a lot in common, though. SRED and NES are both found more often in obese populations. Whether sleep eating causes obesity or not is still up for debate, but it certainly make it harder to lose weight (as I can attest). NES also associates strongly with depression or anxiety. Both disorders have a genetic component and can be passed down in families.
Doctors treating a suspected sleep eater (wherever they lie on the spectrum) start by giving the patient a special questionnaire addressing hunger, caloric intake, familial history, sleep habits, and how long the problem has been going on. The doctor can confirm the diagnosis by performing a sleep study. Patients bring in foods they’d normally consume at night to a sleep lab, and their wakefulness and eating habits are monitored overnight. Both disorders can be treated with serotonin modulation, like taking SSRIs (commonly prescribed for anxiety and depression). Serotonin acts on the hypothalamus, which controls sleeping/waking cycles and feeding behavior. The effectiveness of serotonin modulating drugs also ties back to the high carb intake of sleep eaters – high carb food items increase the availability of tryptophan, which the body converts into serotonin. Sleep eaters might eat high carb foods because their serotonin levels are low. Topiramate, an anti-seizure medication that causes appetite reduction, can also be used to treat NES and SRED. However, topiramate comes with its share of unpleasant side effects, including dizziness, headache, nausea, and skin numbness or tingling. SRED is often successfully treated by addressing any other sleep disorders the patient may have (excluding sleepwalking) or discontinuing any drugs that induce night eating as a side effect. Sedatives, unfortunately, can often exacerbate night eating, especially in NES cases.
My most successful treatment strategy is a combination of avoidance and food stashing. I’m (mostly) vegan during my waking hours, but if there’s ice cream in the house when I go to sleep it will be gone by the morning. When I buy snacks for my friends, I have to make them take home the leftovers or buy things I won’t be tempted by. Luckily, my sleep eating self is vegetarian and hates yogurt cluster cereal. The food I can’t live without, I have my husband hide. Somewhere in my house is a host of gourmet dark chocolate bars, safe from my nocturnal rampages. Life’s a little more boring without being able to keep cinnamon toast crunch and gelato in the house, but at least I can wake up in the morning to minimal food casualties.
Howell, Shenk, and Crow – “A review of nightime eating disorders”
Sleep Medicine Reviews (2009) 13, 23e34
Winkelman, Johnson and Richards – “Sleep related eating disorder”
Handbook of Clinical Neurology (2011), Vol. 98 (3rd series)