With the DSM-5 came the first formal diagnostic criteria for night eating syndrome (NES) in a manual, despite its first documented description nearly 60 years ago (Stunkard, Grace & Wolff, 1955). Slow advances in the understanding of NES and few cross-study comparisons have contributed to this large time lapse between identification and formal definition.
Understanding Night Eating Syndrome (NES)
Current DSM-5 criteria were drafted as “recurrent episodes of night eating, including nocturnal ingestions characterized by waking from sleep and eating or excessive consumption of food after the evening meal; awareness and recall of the night eating; and significant distress or functional impairment associated with night eating.” To achieve a diagnosis of NES, there may be no symptoms better accounted for by cultural norms, binge-eating (BED), another psychiatric disorder, substance abuse disorder or a general medical condition.
Diagnostic Assessment and Co-morbidities
To ensure proper care and treatment of NES it is critical that there is a streamlined and accurate process of assessment and diagnosis. To date, multiple validated self-report measures have been developed. These include the Night Eating Questionnaire (NEQ), Night Eating Syndrome History and Inventory (NESHI), Night Eating Symptom Scale (NESS) and Night Eating Diagnostic Scale (NEDS). A “gold standard” semi-structured interview adapted from the Eating Disorder Examination that assesses for the presence of nocturnal ingestions.
It is possible for NES to be diagnosed comorbidly with other eating disorders. Interestingly, it has been identified that nearly 7-25% of those identified as having NES also met criteria for binge eating disorder (BED). Additionally, approximately 40% of individuals with bulimia nervosa (BN) in an inpatient treatment center reported night eating symptoms and roughly 50% of individuals with bn in an outpatient setting reported night eating symptoms. This pattern of comorbidity is consistent with results from a large Swiss sample of young adults aged 18-26 years old who demonstrated a 10% overlap between NES and BN. When evening ingestions are present, the diagnostic overlap between NES and BED are harder to differentiate. The differentiating factor between the two is the presence of a core belief/pattern of beliefs. With NES, there is a described drive to eat in order to fall back asleep, and an accompanying sense of irritability and/or distress when prevented from evening ingestion.
Behavioral Interventions for Night Eating Syndrome
Two main behavioral treatments are under research and investigation in the treatment of NES. These include progressive muscle relaxation and behavioral weight loss. The progressive muscle technique has been demonstrating strong results as it contributes to lower levels of stress, fatigue, and anxiety, three components that are presumed to increase the likelihood that an individual would engage in nocturnal ingestion. Results from brief, small PMR trials were positive, thought further exploration of PMR for NES is warranted to prove efficacy.
One study has examined the effects of behavioral weight loss on NES. This intervention strategy included a low-calorie diet paired with a regular pattern of eating, exercise and a psychoeducational group therapy focusing on weight loss strategies. Although this intervention did not have a differential impact on weight loss for those with or without NES, only 27% of those who originally met criteria for NES retained the diagnosis at a 6-month follow-up. 62% had reported abstaining from night eating for 3 months.
A third intervention strategy for Night Eating Syndrome is Cognitive-Behavioral Therapy. Abnormal patterns of night eating often lead to the development of unhealthy and/or faulty cognitions about the functions of night eating and one’s control over nocturnal ingestion. When CBT is used to combat night eating, beliefs that one needs to eat to be able to sleep or resume sleep are targeted. Thoughts of being incapable to avoid eating at night and needing to eat to alleviate a sense of anxiety or irritability may also be challenged, should those core beliefs be present.
Some elements of CBT-I (insomnia) have proven highly effective in the treatment of NES and have influenced the theoretical framework for CBT for NES such as improving sleep hygiene, standardizing bedtime and morning awake time/routines etc.
While research and treatment of NES is still fairly new and conducted on smaller scales, the novel research being presented is worthy of review. More information can be found on this topic here. If you or a loved one is struggling with night eating, Columbus Park treatment center in New York City is here to help. Contact us today.