With the house now full of holiday candy and cookies I know I’m gaining weight. But the time for new year’s resolutions is just around the corner, and my resolve to eat less and exercise more usually lasts long enough to help me shed the extra pounds.
Holiday weight gain may not be difficult to reverse for people who eat at conventional mealtimes.
Night eaters, though, have trouble taking off weight. Night eating syndrome, an eating disorder associated with insomnia, is a diagnosis given to people who typically consume at least 25% of their daily calories after dinner and/or during nighttime awakenings. Here’s more about night eating syndrome, its relationship to sleep, and ways to hold it in check.
Symptoms of Night Eating Syndrome
The main symptoms of night eating syndrome (NES) listed in the Diagnostic and Statistical Manual of Mental Disorders 5th edition are these:
- recurrent episodes of night eating that take place after dinner or upon awakening from sleep in the middle of the night,
- awareness of the eating episodes, and
- significant distress or impairment caused by the nighttime eating.
Other common food-related symptoms of NES are (a) lack of desire to eat breakfast and/or skipping breakfast entirely, (b) cravings for specific foods at night, and (c) satisfaction of the cravings with modest amounts of food.
What NES Is Not
NES is not the same as sleep-related eating disorder, in which a person is unaware of nighttime eating; binge-eating disorder, in which bingeing can occur at any time of day and the amount of food consumed is excessive; or bulimia nervosa, characterized by episodes of bingeing followed by purging.
But people with these eating disorders are more likely to have NES than people without them. NES is also more common in people with depression, anxiety, and other psychiatric conditions than in the general population. It’s more common in people who are obese as well.
A Relationship between NES and Sleep Disturbance
Research has shown that NES is associated with sleep disturbance, say the authors of a review paper published in Neuropsychiatric Disease and Treatment. In some cases, night eating serves as a trigger for insomnia. In other cases, the insomnia precedes development of NES.
Some night eaters have trouble falling asleep at the beginning of the night; others have trouble with nighttime wake-ups. Studies also show that people with NES tend to have low sleep efficiency. In other words, they spend a lot of time lying awake in bed.
Psychological and Biological Factors
Accompanying the behavioral aspects of night eating are related sensations and beliefs. People with NES report feeling
- anxious and agitated at night,
- distressed about sleep disruptions, and
- that they must eat to get to sleep.
Research on NES points to biological underpinnings. The serotonin system—which helps to regulate appetite, eating, and circadian rhythms—may be compromised, impairing satiety, dysregulating circadian rhythms, and disturbing sleep.
Eating disorders investigator Jillon Vander Wal, interviewed by Psychiatry Advisor, said this: “According to the biobehavioral model of NES, an inherited trait or predisposition for NES, when combined with stress, reduces the amount of serotonin in the brain, thereby dysregulating circadian rhythms and decreasing satiety. This model suggests that we can intervene in several ways to reduce the symptoms of this disorder.”
Treatments for NES are aimed at decreasing nighttime eating and secondarily at improving mood and facilitating weight loss. Not many controlled studies have been done to assess the efficacy of the various pharmacologic and behavioral options. But here are treatments that have shown potential so far, say the reviewers:
- SSRI medications, especially sertraline (Zoloft) and escitalopram (Lexapro);
- medications that facilitate the action of melatonin;
- progressive muscle relaxation training, alone or combined with patient education and exercise; and
- cognitive-behavioral therapy (CBT), aimed at helping patients develop healthier habits and attitudes. The main goal of CBT for NES is “to correct the delay in circadian eating rhythms, while simultaneously interrupting the relationship between erroneous cognitions and night eating and sleep.”
If you tend to skip breakfast and eat at night, does your eating pattern affect your sleep? If so, how?