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OSFED: A Common Eating Disorder Many People Don’t Know About

Despite there being many misconceptions and assumptions about eating disorders, many of them are well-known by people outside the mental health treatment field. Most people recognize disorders like bulimia nervosa (BN), anorexia nervosa (AN), and binge eating disorder (BED), and can describe the basic symptoms, even if they’re holding on to misguided ideas like “every person with AN is underweight.” While these disorders are clearly defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM-V), which is the authoritative guide to mental health disorders, some people display disordered eating behavior in ways that don’t match the criteria for AN, BN, or BED.  

That’s where OSFED (Other Specified Feeding or Eating Disorder) comes into the picture.

More Than a “Miscellaneous” Category

An OSFED diagnosis is made when a person has eating and/or exercise habits that negatively impact their life but do not meet the diagnostic criteria of a major form of eating disorder. For example, a person might restrict their calories and avoid meals, but not lose a significant amount of weight, which is one of the criteria for anorexia nervosa. Or a person may purge from time to time, but without a binge eating episode preceding that action. Because there is no binge eating involved, this behavior doesn’t qualify for a diagnosis of bulimia nervosa. 

However, disordered eating behavior that doesn’t match the criteria for AN, BN, BED, or ARFID can still be dangerous. 

It’s tempting to think of OSFED as a catchall category or a “miscellaneous” file for types of disordered eating behavior that aren’t as serious as the more well-known types. That’s a very dangerous attitude; OSFED can have as many serious health consequences as anorexia or bulimia and failing to take them seriously can result in heart disease, nutritional imbalance, osteoporosis, various mental health disorders, and even death in extreme cases. 

Marginalizing OSFED as less serious than the others may also lead to underreporting and underdiagnosing as well. People with untreated eating disorder will often cover up or discount their disorder to avoid intervention or having tough conversations with their family or doctors. If they express the idea the OSFED isn’t a “real” eating disorder or isn’t as serious, there is a much higher chance that the disorder will go untreated.

What Behaviors Does Other Specified Feeding or Eating Disorder Include?

In addition to symptoms of other eating disorders that don’t fulfill their diagnostic criteria, OSFED contains several forms of a typical eating disorder behaviors as well as a few forms of disordered eating which do not appear in AN, BN, BED, or ARFID. These include five less-common eating patterns that occur independently. 

It’s also important to note, having OSFED does not preclude a person from having another form of eating disorder. For example, a person may restrict calories most of the time, but also purge at other times. This person might have AN and purging disorder (one of the OSFED types) simultaneously; each treatment program must be as varied as the individual being treated.

Here are the most common types of disordered eating behavior included in the DSM-V definition of OSFED:

  • Atypical Anorexia Nervosa:

    In this situation, all the criteria for anorexia nervosa are met (distorted body image, calorie restriction, weight loss), except that the person remains in a “normal” weight range. This can occur if the person was significantly overweight before displaying AN symptoms. On the other hand, in some individuals, despite restricting calories, their weight doesn’t go below a certain point. While it may seem less serious than diagnosable AN, the truth is most of the same health risks apply, as the person does not receive adequate nutrition. A person with AAN may experience malnutrition, weakened bones, hair loss and brittle nails, and other symptoms.

  • Binge Eating Disorder (of low frequency and/or limited duration):

    Binge eating disorder is defined as a person regularly and compulsively eating large amounts of food in short periods, known as binge eating episodes. This is frequent and continuous over at least three months. In low frequency/limited duration BED, the person engages in binge eating episodes, but not as often or for shorter durations. For example, they might binge eat nightly for a week or two at a time, then revert to a “regular” eating schedule for the next month. These binge eating episodes can lead to weight fluctuations and weight gain, which result in many of the health complications associated with obesity. BED of all forms is also frequently linked with low self-esteem, depression, and anxiety.

  • Bulimia Nervosa (of low frequency and/or limited duration):

    Similar to low frequency/limited duration BED, this form of bulimia nervosa features the same disordered behaviors but in a less regular, shorter period. Bulimia nervosa is a condition in which the person has binge eating episodes on a regular basis, which are then followed by purging actions to remove the calories taken in. Purging is most commonly self-induced vomiting, but can also include abuse of laxatives and diuretics, dieting, and excessive exercise. BN also normally includes flawed body image and a history of dieting. People with BN aren’t always thin or emaciated; most often they’re of a “normal weight” or even overweight.

  • Purging Disorder:

    In people with purging disorder, many of the behavioral symptoms of bulimia nervosa are present, except for binge eating episodes. Purging disorder takes effect after meals (although not necessarily directly after), when in an attempt to control weight or calorie intake, the person purges. One major difference between purging disorder and BN is that BN sufferers report a greater feeling of loss of control over their eating; although BN may be more severe, purging disorder is still a potentially fatal disorder if left untreated.

  • Night Eating Syndrome:

    Perhaps the least understood of the OSFED disorders, Night Eating Syndrome (NES) involves recurrent episodes of night eating. This might mean eating after awakening from sleep (excluding breakfast), or by excessive food consumption after the evening meal. This syndrome can be diagnosed only when there is not an environmental or social norm that would cause the person to recurrently eat in the middle of the nights, such as a night shift work schedule or societal tradition of late meals. The behavior also has to cause the individual significant distress/impairment such as insomnia, weight gain, or anxiety.Lastly, to diagnose NES, the behavior cannot be better explained by another mental health disorder (e.g. BED).

What’s in a Name?

Until recently, OSFED was known as Eating Disorder Not Otherwise Specified (EDNOS) and was actually the most commonly diagnosed eating disorder, since the criteria for AN and BN are relatively narrow, and binge eating disorder was not yet listed by the DSM-V as an official eating disorder. BED is not the most commonly diagnosed disorder, since its introduction to the DSM in 2013.  

Unlike OSFED, EDNOS really was a “catchall” category, which came with pluses and minuses. On the plus side, the wide variety of disordered eating disorder behaviors in EDNOS meant that more people could receive treatment due to the less specific criteria. More negatively, there was a perception that EDNOS, without specific criteria, was less of a “real” eating disorder and people with EDNOS didn’t need treatment as often. 

The more specific criteria of OSFED have another advantage in terms of securing treatment; with the aspects of the disorder clearly laid out in the DSM-V, it’s easier to convince insurance companies that it’s a serious condition that requires professional treatment. Thankfully some people who might have been bypassed for treatment in the past can now be covered. 

How Can OSFED Be Treated?

As with every kind of mental health disorder, a combination of talk therapy, cognitive behavioral therapy, and in some cases medication (medication in eating disorder treatment is controversial; it’s generally prescribed on a case by case basis rather than as a standard part of treatment) provide individuals with the best chance of a full recovery. 

Most eating disorder treatment centers are evidence-based, meaning the therapy is centered around provable methodologies based on clinical discovery and best practices. This usually includes treatment methods like CBT (Cognitive Behavioral Therapy), a one-on-one dialogue between client and therapist that retrains the client’s thinking processes. During CBT sessions, disordered thoughts are identified and debunked; over time the client will come to realize that their self-perception and body image are disordered. The pair can then work to objectively correct these flawed thinking patterns, and then modulate eating behaviors to reach a healthier balance.

Aside from one-on-one therapy sessions, other useful therapeutic techniques involve group therapy sessions with peers as well as family sessions. The former allows people to support and learn from people in similar situations and make group progress in recovery; the latter help the family understand the challenges of recovery and learn how to support their loved one when they return to “regular life.”

If you or a loved one is displaying disordered eating behaviors that don’t fit cleanly into the clear descriptions of AN, BN, BED or ARFID, there’s a chance that OSFED may be present. If this is the case, don’t downplay the seriousness of the situation; it’s better to consult a professional and be told there is not an issue than to let disordered behavior continue without treatment.


Melissa Orshan Spann, PhD, LMHC, RTY 200, is Chief Clinical Officer at Monte Nido & Affiliates, overseeing the clinical operations and programming for over 50 programs across the U.S. Dr. Spann is a Certified Eating Disorder Specialist and clinical supervisor as well as an accomplished presenter and passionate clinician who has spent her career working in the eating disorder field in higher levels of care. She is a member of the Academy for Eating Disorders and the International Association of Eating Disorder Professionals where she serves on the national certification committee, supervision faculty, and is on the board of her local chapter. She received her doctoral degree from Drexel University, master’s degree from the University of Miami, and bachelor’s degree from the University of Florida.