science

Night eating syndrome

Night eating syndrome is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Night eating syndrome rather than just read about it. In short: Night eating syndrome (NES) is classified as an Other Specified Feeding or Eating Disorder (OSFED) under the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). It involves recurrent episodes of night eating after awakening from sleep or after the evening meal.

Key takeaways

Night eating syndrome belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Night eating syndrome to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Night eating syndrome from memory before moving on to harder problems.

Reference excerpt

Night eating syndrome (NES) is classified as an Other Specified Feeding or Eating Disorder (OSFED) under the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). It involves recurrent episodes of night eating after awakening from sleep or after the evening meal. Awareness and recall of the eating is present, which is a key characteristic that differentiates the disorder from Sleep-Related Eating Disorder (SRED). Although there is some degree of comorbidity with binge eating disorder (BED), it differs from binge eating in that the amount of food consumed in the night is not necessarily objectively large nor is a loss of control over food intake required. The syndrome causes significant distress or functional impairment and cannot be better explained by external influences such as changes in the sleep-wake cycle, social norms, substance use, medication, or another mental or medical disorder.

History NES was originally described by Albert Stunkard in 1955 and is currently included in the other specified feeding or eating disorder (OSFED) category of the DSM-5. Most of the updated literature relating to NES has been published in recent years due to its recent changes in the DSM-5.

Epidemiology NES affects both men and women, between 1 and 2% of the general population, and approximately 10% of obese individuals. Newer research suggests that the overall prevalence of NES ranges from 2.8% to 15.2% in clinical patients with eating disorders, obesity, and/or bariatric surgery. Previously, the age of onset was typically in early adulthood (spanning from late teenage years to late twenties) and was often long-lasting, with children rarely reporting NES. However, newer studies have suggested that age is not a risk factor for NES, yet this evidence is still lacking. Other social-demographic factors such as income, gender, education level, children, living with a romantic partner, and smoking levels do not have an effect on NES. Furthermore, there have been contradictory conclusions on whether a higher BMI is a risk factor of NES, or if it is simply a consequence of night eating behavior. There has been no specific statistics regarding NES and mortality.

Comorbidities NES has a substantial association with medical diagnoses such as obesity, sleep apnea, hypercholesterolemia, polycystic ovarian syndrome, and diabetes mellitus type II (T2DM), and psychiatric diagnoses such as binge eating disorder, anorexia nervosa, bulimia nervosa, generalized anxiety disorder, major depressive disorder, and substance use disorders. In contrast to eating disorders like anorexia nervosa, NES does not necessarily depend on a person's Body Mass Index (BMI). It can occur in individuals with a weight considered normal for their age and height but is most commonly observed and studied in those with obesity. In fact, NES has been found to be a risk factor for an earlier onset of obesity. NES is most commonly comorbid with excess weight; as many as 28% of individuals seeking gastric bypass surgery were found to have NES in one study. Night eating syndrome has also been associated with diabetic complications. Many people with NES also experience depressed mood, post-traumatic stress disorder, and anxiety disorders. People with NES have been shown to have higher scores for depression and low self-esteem. NES may also have an association with personality traits, such as harm avoidance, self-directedness, and impulsivity. It has been demonstrated that nocturnal levels of the hormones melatonin and leptin are decreased. Individuals tend to have poorer sleep quality and higher levels of insomnia. Often times, people with NES are unaware of their condition due to it often being overshadowed by other comorbidities.

Diagnosis Specific research diagnostic criteria have been proposed outside of the DSM-5 and include: (A) Evening hyperphagia (consumption of 25% or more of the total daily calories after the evening meal) and/or nocturnal awakening and ingestion of food two or more times per week. (B) Awareness of the night eating to differentiate it from the parasomnia sleep-related eating disorder (SRED). (C) Three of five associated symptoms must also be present: lack of appetite in the morning, urges to eat at night, belief that one must eat in order to fall back to sleep at night, depressed mood, and/or difficulty sleeping. (D) The eating pattern causes significant distress or interferes with daily functioning. (E) The disordered pattern of eating has been maintained for at least 3 months. (F) The pattern is not attributable to substance use, medical conditions, medication, or another psychiatric disorder.

Testing When an eating disorder (ED) is suspected, health professionals should test using a validated tool: the Night Eating Questionnaire (NEQ), the Night Eating Diagnostic Questionnaire (NEDQ), the Eating Disorder Examination Questionnaire (EDE-Q), the Night Eating Syndrome History and Inventory (NESHI), or the Eating Among Teens Survey (EAT-II).

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Night eating syndrome

Start with the simplest possible case. Write down what Night eating syndrome claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Night eating syndrome before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Night eating syndrome ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Night eating syndrome

In research: Night eating syndrome appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Night eating syndrome in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Night eating syndrome is common in secondary-school and first-year university syllabi. It links to neighbouring topics Eating disorders, Parasomnias, Syndromes, so understanding it makes those chapters shorter.
In everyday life: Look for Night eating syndrome outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Night eating syndrome in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Night eating syndrome means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Night eating syndrome out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Night eating syndrome in simple terms?

Why does Night eating syndrome matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Night eating syndrome?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Night eating syndrome.