Other Specified Feeding or Eating Disorder (OSFED)


Other Specified Feeding or Eating Disorder (OSFED)

*** Disclaimer: The following article includes information derived from our clinical team’s impressions as specialized professionals working directly with Eating Disorders in Windsor/Essex County.

Other Specified Feeding or Eating Disorder, commonly referred to by its acronym “OSFED”, is a clinical category of eating disorders which includes conditions that do not fully fit the criteria of other diagnoses. It is important to note that one does not necessarily receive the diagnosis of “OSFED”, as it is an umbrella term that refers to 5 “other specified” presentations. Rather, individuals typically receive a diagnosis outlining the type of OSFED presentation that best suits their reported symptoms.

In the 2018-2019 year, we collected data on our active clients to determine how frequent each eating disorder diagnosis is at BANA. We found that 4.6% of our client population has been diagnosed with some presentation of OSFED. It is important to remember that individuals with a diagnosis categorized under OSFED can have a range of unique symptoms, and may be commonly overlooked due to their inability to fit clearly into other eating disorder outlines.

The 5th rendition of the Diagnostic Statistical Manual (DSM-5) is the current guideline used in North America to diagnose all mental health disorders. It outlines the requirements that must be met in order to receive any diagnosis within its pages. Some professionals speculate that presentations within this clinical category may receive their own diagnostic title in future renditions of the DSM.


Shared Characteristics of the 5 OSFED Presentations:

  • Predominant symptoms characteristic of a feeding/eating disorder, but do not meet the full criteria for any of the other feeding/eating disorder diagnostic classes
  • Cause clinically significant distress or impairment in social, occupational, or other important areas of functioning

The 5 “Other Specified” Presentations:

  1. Atypical Anorexia Nervosa -> all of the criteria for anorexia nervosa are met, except that despite significant weight loss, the individual’s weight is within or above the normal range
  2. Bulimia Nervosa of Low Frequency and/or Limited Duration -> all of the criteria for bulimia nervosa are met, except that the binge eating and inappropriate compensatory behaviours occur less than once a week, and/or for less than 3 months
  3. Binge-Eating Disorder of Low Frequency and/or Limited Duration -> all of the criteria for binge eating disorder are met, except that the binge eating occurs less than once a week, and/or for less than 3 months
  4. Purging Disorder -> recurrent purging behaviours occur that influence weight or shape (ex: self-induced vomiting, misuse of laxatives, diuretics or other medications) in the absence of binge eating
  5. Night Eating Syndrome -> recurrent episodes of night eating, as manifested by eating after awakening from sleep, or by excessive food consumption after the evening meal. There is awareness and recall of the eating. The night eating is not better explained by changes to the individual’s sleep/wake cycle or by local social norms, nor is it attributable to another eating disorder diagnosis, mental health disorder, substance use or health condition.


The primary difference between atypical anorexia from the classical-presentation of anorexia nervosa is weight. Individuals with atypical anorexia do not meet the low-weight criteria that an individual with anorexia nervosa would present with. However, a common misconception about atypical anorexia is that these individuals are “just above” the BMI cut-off for anorexia nervosa. While this is still true – and some individuals do fall just above this cut-off – it overlooks the fact that individuals diagnosed with atypical anorexia could be of many different shapes/weights/sizes.  This includes individuals who may be considered average to above-average weight.

It is important to note that atypical anorexia may be overlooked on account of weight. Many professionals – or even loved ones and/or the individuals themselves – may “miss” symptoms or disordered thoughts/behaviours due to the individual not meeting the expected “emaciated” and low-weight appearance assumed of anorexia.

Another common misconception about atypical anorexia is that it is not as severe as anorexia nervosa, and that it is a precursor to the classical presentation. It is important to debunk this myth, as everyone’s body reacts differently to symptoms and restrictive measures. As restriction occurs over time, your body adjusts to the ways in which it attains energy, and this does not always mean weight loss. While some individuals with atypical anorexia may become underweight with time, this is not always the case. Therefore, just because someone’s weight does not align with the diagnostic criteria for anorexia nervosa does not mean that their symptoms and severity are taken any less seriously. Individuals with atypical anorexia still have an eating disorder, and therefore face struggles just as real and as valid as any other.


The only difference between these OSFED presentations and the diagnoses of bulimia nervosa (BN) and binge eating disorder (BED) is that of frequency and duration. Bulimia nervosa and binge eating disorder require symptoms to be present at least once a week for three or more months. OSFED acknowledges individuals who fall outside of this time-window; doing so can allow for a treatment plan to be developed, and their symptoms to be addressed before they potentially worsen.

For more information regarding the symptoms associated with bulimia nervosa or binge eating disorder, please see our other articles that cover these diagnoses specifically.


Purging disorder is another eating disorder that is often misunderstood and overlooked. One of the primary reasons BANA has seen purging disorder “fall below the radar” is due to the lack of binge-eating episodes. Many individuals – professionals included – do not recognize purging disorder due to the fact that purging alone is often not seen as disordered, especially because many of these behaviours have normative uses (for example, exercising for health and vomiting due to illness). When paired with binge behaviours, purging is more clearly seen as problematic. It is important to keep in mind that motives behind purging can differ vastly; if the motives for purging are to control one’s shape or weight – whether binge eating is present or not – this still aligns with eating disorder criterion.

Purging behaviours are often done in secrecy due to embarrassment, shame and guilt; these behaviours can be hidden from loved ones and professionals, making the disorder difficult to observe.  Also, purging disorder is not limited to self-induced vomiting – another misconception about this diagnosis – and can often be overlooked if the individual is purging through other means. For more information regarding types of purging behaviours used for weight/shape control, please visit our article on Bulimia Nervosa.


Although the DSM-5 does not provide a distinct set of criteria for diagnosing Night Eating Syndrome, some professionals have proposed criteria based on factors identified in research. The following diagnostic criteria was suggested by Allison and colleagues in their article, “Proposed Diagnostic Criteria for Night Eating Syndrome” (2010):

A. Daily pattern of eating demonstrates significantly increased intake in the evening and/or nighttime, as manifested by one of both of the following:

  • At least 25% of food intake is consumed after the evening meal
  • At least 2 episodes of nocturnal eating per week

B. Awareness and recall of evening/nocturnal eating episodes are present

C. Presents with 3 or more of the following features:

  • Lack of desire to eat in the morning, or omitting breakfast of 4+ days per week
  • Strong urge to eat between diner and sleep onset, and/or during the night
  • Sleep onset or sleep maintenance insomnia present on 4+ nights per week
  • Belief that one must eat in order to initiate or return to sleep
  • Frequently depressed mood, and/or mood worsens in the evenings

D. Features have been present for at least 3 months

Research has demonstrated that Night Eating Syndrome – or NES – commonly co-occurs with other eating disorder diagnoses; research shows anywhere between a 5-43.4% comorbidity with other eating disorders. It appears as though NES has the least overlap with anorexia nervosa; however, reasons for this remain unclear or under-researched. NES is most frequently seen to overlap with binge eating disorder or bulimia nervosa. Episodes of night eating may be commonly associated with or mistaken for binge episodes, and lack of desire to eat in the morning could be seen as compensatory behaviour. Many professionals still believe that NES is not a distinct diagnosis, but rather a variant of BED or BN. However, opposing professionals argue that core differences – such as disruption of sleep, underlying behavioural constructs and psychological motives – are what make NES a distinct condition. Our BANA clinicians argue the latter, as we have seen NES to be quite unique from other eating disorders, specifically due to its relation to sleep.

One common misconception about NES is that one needs to feel “out of control” with their eating, and may not have any recollection of their episodes. As we see in the proposed criteria, lack of control is not a defining feature, and awareness of episodes is a criterion that should be met for diagnosis. Regarding control, some individuals with a diagnosis of NES have reported that night eating has become habitual, and they may even report having become accustomed to the disruption eating patterns cause on sleep and mood.


One common misconception about OSFED is that it is not as important or as severe as other eating disorders. This misconception can be dangerous, as some research has shown individuals with OSFED may be just as likely as individuals with other eating disorder diagnoses to face medical consequences from their disorder; to be at risk of hospitalization and/or mortality due to their eating disorder; and to score just as high on measures of eating disorder thoughts and behaviours.

Myths about OSFED being less severe overlook one important fact about humans in general: we are all unique. It is unrealistic to expect everyone struggling with disordered eating and body image to fit perfectly into a small list of diagnostic criteria. OSFED represents the reality that individuals cannot always be deduced to a limited set of categories, and we may all face different struggles and symptoms that are not always so clear-cut.


Other specified feeding and eating disorders may be difficult to identify due to the variety of presentations included within the umbrella, as well as their inability to fit “clearly” into other eating disorders’ diagnostic criteria. If any of the information outlined in this article hit-home, but you’re not sure if they meet all the requirements for a diagnosis, do not hesitate to contact us through general intake. We can meet with you to discuss potential symptoms, and can support you through some of your concerns.

Our general intake number is: 1-855-969-5530


Allison, K. C., Lundgren, J. D., O’Reardon, J. P., Geliebter, A., Gluck, M. E., Vinai, P., … & Engel, S. (2010). Proposed diagnostic criteria for night eating syndrome. International Journal of Eating Disorders43(3), 241-247.

American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Washington, DC: Author.

Centre for Clinical Interventions. (2018). What are eating disorders. Retrieved from https://www.cci.health.wa.gov.au/

Eating Recovery Center. (2018). Night eating syndrome: The eating disorder we need to talk about. Retrieved May 22, 2020, from https://www.eatingrecoverycenter.com/blog/may-2018/night-eating-syndrome-the-eating-disorder-we-need-to-talk-about

Gwen, M. (2019). Top 5 myths about atypical anorexia. Retrieved May 25, 2020, from https://www.nationaleatingdisorders.org/blog/top-5-myths-about-atypical-anorexia

Mitchell, J. E. (2012). Night eating syndrome: Research, assessment, and treatment. Guilford Press.

National Eating Disorders Association. (2019). Eating disorder myths. Retrieved from https://www.nationaleatingdisorders.org/toolkit/parent-toolkit/eating-disorder-myths

National Eating Disorders Association. (2018). Other specified feeding or eating disorder. Retrieved from https://www.nationaleatingdisorders.org/learn/by-eating-disorder/osfed

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