Night eating syndrome is an eating disorder characterized by a delay in the normal circadian (24 hour) pattern of food intake. For most people, appetite is related to circadian rhythms, so that meals are consumed between early morning and early evening. However, in night eating syndrome, there is a delay in this normal pattern: eating begins in the afternoon and continues into the night. Energy intake is reduced in the first half of the day and greatly increased in the second half. Sleep is disrupted in the service of food intake. It is estimated that approximately 1.5% of the adult population suffers from night eating syndrome.
Night eating syndrome may be distinguished from sleep-related eating disorder (SRED), which is not an eating disorder at all but a sleep disorder. People with SRED eat while sleepwalking or while not fully awake. People with SRED are not aware of what they are doing and may wake up to find dishes or food waste and have no memory of eating at all. By contrast, people with night eating syndrome are fully awake and aware of what they are consuming.
The core feature of night eating syndrome is abnormally increased food intake in the evening and nighttime, characterized by 1) the consumption of at least 25% of daily calories after the evening meal and/or 2) awakening to eat at least two times per week. Occasional late night snacks do not constitute night eating syndrome. Individuals most commonly consume small amounts of food at a time, but they report eating multiple times over the course of the night. Foods typically consumed include leftovers and snack foods that are quick and easy to prepare in the middle of the night, such as cereal or cookies.
Health Issues From Night Eating Syndrome
Night eating syndrome is associated with other features including lack of morning hunger, depression, interrupted sleep, urges to eat at night, and the belief that eating will help one sleep. There is some overlap with binge eating disorder, but people with night eating syndrome may or may not binge eat.
People with night eating syndrome report significant distress. They commonly worry about weight gain and the loss of sleep. Night eating syndrome is found in higher rates among obese adults than in the general population, but is found within all weight ranges and does not necessarily lead to weight gain. Night eating syndrome may cause acid reflux and may contribute to dental cavities (particularly if individuals go back to sleep without brushing their teeth).
The exact cause of night eating syndrome is not known. As with other eating disorders, there is evidence for a genetic connection. Stress, negative mood, and anxiety are a few known triggers. Signs that a family member may be suffering from night eating syndrome include missing food, crumbs and wrappers in the bed, and regular sleep disturbance.
Potential treatment for night eating syndrome may include cognitive behavioral psychotherapy involving the maintenance of food and sleep records and the modification of eating and sleep behaviors as well as stress management. Regularly eating breakfast is important to reset the circadian rhythm; this is often challenging for patients with night eating syndrome. Treatment may also include working with a dietitian to help develop meal plans that distribute caloric intake throughout the day so that the person is not so vulnerable to caloric loading at night.
There is some limited research on the benefits of some antidepressants for night eating syndrome. There is no research to confirm that supplements are beneficial, although many people try them. Bright light therapy, which is thought to reset circadian rhythms and is used for seasonal affective disorder, is being investigated as a potential treatment.
If you or someone you know suffers from night eating syndrome, it is important to seek help.
Written by Dr. Lauren Muhlheim – 2014