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Eating Disorders

Anorexia, Bulimia, Bingeing, and OSFED: More Alike Than Different

Subtle changes can shift one eating disorder diagnosis to another.

Key points

  • An individual's eating disorder diagnosis can change due to a shift in their weight or compensatory behaviors.
  • A person’s size does not and cannot reveal which eating disorder they have.
Courtesy of Denise Robertson
Source: Courtesy of Denise Robertson

The media has portrayed the looks of the three most well-recognized eating disorders—anorexia, bulimia, and binge-eating disorder (BED)—as distinct, and judgments are often made about the severity and social stigma of each. OSFED, which stands for "other specified feeding and eating disorder," is the catchall term for behaviors and attitudes almost fit one of the other three. It, too, tends to elicit judgments as “not enough to be an actual eating disorder." As an eating disorders specialist, I’m repeatedly struck by how similar these four disorders tend to be despite the perceived differences.

General Similarities

All four:

  • Involve maladaptive, unnatural, non-intuitive eating.
  • Can result in malnutrition.
  • Come with negative physical consequences.
  • Reduce the quality of a person’s life.
  • Can fly under the radar of being noticed as a problem or illness.


Many of our educational books based on the most current Diagnostic and Statistical Manual of Mental Disorders (DSM-5) focus on weight as a determining factor for which eating disorder diagnosis applies. For example:

  • The primary difference between the diagnosis of anorexia nervosa with the subtype of binge-purge and bulimia nervosa can be a few pounds. Anorexia nervosa with bingeing and purging is bulimia nervosa, basically—just at a low weight.
  • The difference between anorexia nervosa (typically slim) and OSFED’s atypical anorexia nervosa (typically average to large) is weight. Data is evolving, but atypical anorexia nervosa has been shown to be as serious as anorexia nervosa. This includes medical risks and consequences.

Reminder: For many years, anorexia nervosa was recognized as having the highest mortality rate of any psychiatric disorder. It now shares that distinction with substance use disorders (e.g., opioid), which underscores the dangerousness of anorexia nervosa, typical and atypical. Do you think weight is enough to determine one diagnostic title over another (e.g., anorexia over bulimia or OSFED over anorexia)?

Compensatory Behaviors

The act of compensating or not compensating for having eaten can change one eating diagnosis into another, too. The following phrases can represent compensation: “get rid of,” “burn off,” and “balance out” after eating. Compensatory behaviors fall into two categories:

  1. Non-purging matches primarily to activities such as exercising and dieting (aka restricting food). Both come with an underlying intention of controlling or manipulating calories, weight, body size, or food intake.
  2. Purging involves methods that empty the body, such as vomiting, which is probably the most stereotypically portrayed purging behavior in pop culture and media.

There are other examples of both, but it’s often best not to name them since people vulnerable to eating disorders can get ideas.

Compensatory behaviors can occur in all four eating disorders mentioned:

  • Someone with binge-eating disorder binges but, according to the DSM-5, doesn’t regularly compensate for what they ate.
  • Someone with bulimia nervosa binges and regularly compensates by either non-purging or purging methods.
  • Someone with anorexia nervosa may or may not binge and regularly compensates by either non-purging or purging methods.
  • Someone with OSFED may compensate by either non-purging or purging methods, for eating or bingeing, and depending on their specific beliefs and behaviors.

Question: If you struggle with binge eating or know someone who does, is there some type of compensation occurring after a binging episode or episodes? If so, are the compensatory behaviors happening regularly (e.g., at least once a week)? I suspect that many people who’ve been given binge-eating disorder as their diagnosis may have, or have had, bulimia nervosa.


I often wish that “eating disorder” was the only diagnosis available within eating disorders. Titles can matter to the people struggling and their loved ones. For example:

  • People can view anorexia nervosa as sort of the ultimate eating disorder diagnosis.
  • People can think they aren’t sick enough to need (or deserve) help if they have OSFED.
  • Some people with bulimia nervosa believe they failed; they didn’t do it well enough to earn the title of anorexia.

If you might have an eating disorder or disordered eating, please seek help from a professional who is thoroughly trained in eating and body image issues. A professional usually pursues an eating-disorders specialty track, which involves thousands of hours of training and education. I encourage you to ask potential providers about their paths to, and background in, this specialty. Your healing is worth it.

This post expresses my opinions, does not present the full criteria of eating disorders, is for informational purposes only, and does not substitute for therapy or professional advice.


American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.).

Chesney, E., Goodwin, G. M. & Fazel, S. (2014). Risks of all-cause and suicide mortality in mental disorders: a meta-review. World Psychiatry, 13, 153-160.

Garber, A. K., Cheng, J., Accurso, E. C., Adams, S. H., Buckelew, S. M., Kapphahn, C. J., Kreiter, A., Le Grange, D., Machen, V. I., Moscicki, A. B., Saffran, K., Sy, A. F., Wilson, L., & Golden, N. H. (2019). Weight loss and illness severity in adolescents with atypical anorexia nervosa. Pediatrics, 144(6). e20192339. 10.1542/peds.2019-2339