Nocturnal binge eating

Like many people, I enjoy a late-night snack—especially when the Boston Red Sox are playing a late game or if I'm burning the midnight oil to get some work done. The occasional late-night snack is nothing to worry about. But nightly bingeing merits a closer look. Experts debate the value of creating a specific diagnostic category for nocturnal over-eating, but they don't debate the significance of the problem.

Sleep-related eating syndrome is a highly publicized malady, though it's not clear how common it is. People with this problem eat while sleepwalking, or in a twilight state between sleep and wakefulness. They generally aren't conscious of what they are doing, so they may describe waking to find the bed littered with candy wrappers — with no memory of consuming the candy itself.

A better documented problem is night eating syndrome, in which people do the majority of their eating late at night. A 1999 study in the Journal of the American Medical Association found that by 6 p.m., people with night eating syndrome consumed a little more than a third of daily calories, while a control group had consumed almost three-quarters. Between 8 p.m. and 6 a.m., however, the night eaters consumed 56% of daily calories, while controls consumed only 15%.

The few studies of prevalence show that night eating syndrome may affect one or two out of 100 people in the general population. First described in the 1950s by Dr. Albert J. Stunkard, a psychiatrist at the University of Pennsylvania, researchers have recently explored its link to weight gain. The problem affects anywhere from 9% to 14% of people seeking treatment at obesity clinics, and as many as 27% of severely obese people.

Night eating also shows up in mental health clinics. In one study of psychiatric outpatients in Pennsylvania and Minnesota, 12% had night eating syndrome. Night eaters in this study were also much more likely than other individuals to be substance abusers. Other research indicates that people with night eating syndrome tend to suffer from a distinct form of depression. In contrast to the usual pattern, night eaters tend to become even more depressed during the evening.

It's not clear what causes night eating syndrome, and why it is associated with depression or substance abuse. One theory is that night eating syndrome involves a disruption in hormones that help regulate sleep, appetite, or mood. Because late-night snacking usually involves carbohydrate-rich "comfort" foods, this theory holds that night eating syndrome is a form of self-medication.

Until more is known about night eating syndrome, it's probably best to take a broad approach to diagnosis and treatment. A general physical exam can rule out other problems. Treating any underlying mental health problems, such as depression or anxiety, can help a person improve eating patterns. A dietitian can provide advice about how to better pace meals throughout the day, which might help break the cycle of late-night eating. Preliminary studies indicate that the anticonvulsant topiramate (Topamax) or an SSRI antidepressant, such as sertraline (Zoloft), may help.

Case reports indicate some people can improve their eating patterns by being mindful of the problem and trying to identify its triggers. Stress reduction techniques may help avert trips to the refrigerator.

Attending to underlying stress, anxiety, or depression may help a person get to sleep earlier, too. Scientists note that sleeping and eating are likely to be connected, as they have discovered a link between a lack of sleep and weight gain. That's all the more reason to replace a late-night snack with a late-night nap.

Do you consider yourself a late-night binge eater? What strategies have helped you get your eating under control?

Dr. Michael Miller has been on staff of the Beth Israel Deaconess Medical Center, a large teaching hospital in Boston, for more than 25 years. He is also an Assistant Professor of Psychiatry at Harvard Medical School.

Mental Health Letter
The field of mental health is rapidly evolving, and whether your interest is professional or personal, staying informed about these mental health issues is no easy job. The Harvard Mental Health Letter is a source of mental health news you can trust—and it comes directly from the more than 8,000 doctors and researchers at Harvard Medical School.

Are you Living With Anxiety? Connect with others with similar health concerns and issues. Click here to join the group.