Night-Time Eating Episodes

Many individuals experience episodes of waking up to eat at night or eating during sleep in an unconscious manner. This phenomenon is sometimes considered normal among people. However, when these behaviors persist over a long period and occur repeatedly, they indicate potential physical and psychological health problems.

There are two main disorders associated with night-time eating: NES (Night Eating Syndrome) and SRED (Sleep-Related Eating Disorder).

NES is a well-characterized disorder within medical practice. It was first introduced in the literature by Albert Stunkard in 1955. At that time, NES was recorded as abnormal eating behavior occurring during periods of stress. Since the 1990s, more research has been conducted to study and understand this disorder.

The main diagnostic criteria of NES are:

1. Consuming at least 25% of the total daily calories at night, at least twice a week, for a duration of three months;
2. Morning anorexia (loss of appetite), strong urges to eat in the evening and at night, frequent insomnia, the need to eat to fall asleep, and worsening mood in the evening;
3. Functional impairment and distress.

During Night Eating Syndrome episodes, the individual remains conscious, remembers what they ate in the morning, and parasomnias (such as sleepwalking) are not observed. In NES, the person either wakes up specifically to eat or eats when awakened at night.

Individuals suffering from this disorder may also experience emotional disturbances such as high anxiety, depression, concerns about body shape, low self-esteem, and, most importantly, guilt for eating at night. Depression in NES is characterized mainly by worsening mood in the evening.

NES not only affects psychological health but also causes disturbances in the neuroendocrine system: cortisol levels increase, melatonin levels decrease, and leptin levels do not normalize at night, weakening the ability to suppress appetite and stop food intake.

SRED (Sleep-Related Eating Disorder), unlike NES, is characterized by eating at night with little or no awareness, and parasomnias are observed.

The main diagnostic features of SRED are:

1. Behaviors that can lead to physical harm, such as ingestion of medications, toxic substances, risk of injury with sharp objects, or fire hazards;
2. Repeated food intake during awakenings from sleep;
3. Significant distress and functional impairment;
4. No defined duration; the behavior is chronic and occurs frequently.

Due to genetic predisposition related to parasomnias (such as sleepwalking), SRED is thought to have a potential genetic component. In 20–25% of cases, similar behaviors have been observed in family members.