Introduction
Welcome back to Treehouse Counseling’s blog series about eating disorders. If you missed it, make sure to read part one, where we explored the difference between eating disorders and disordered eating.
For the purposes of this article, we will broadly define an eating disorder as a chronic, severe disruption in one’s relationship to food (and often body image), notable due to its severe and persistent negative impact on biopsychosocial functioning. While often grouped together, eating disorders have distinct subtypes with unique symptoms, struggles, and diagnostic criteria. Understanding these differences is crucial for recognition, compassion, and seeking appropriate help. This post will outline the key characteristics of five primary eating disorder subtypes: Anorexia Nervosa, Bulimia Nervosa, Binge-Eating Disorder, ARFID, and OSFED.
Anorexia Nervosa (AN)
Often considered the most recognizable eating disorder, anorexia nervosa (AN) also has the highest mortality rate of any psychiatric condition (Auger et al., 2021). Its core features are marked by restriction of energy intake leading to significantly low body weight (in context of age, sex, developmental trajectory, and physical health), intense fear of gaining weight, and disturbed perception of body weight/shape.
Originally, AN was only recognized in individuals who demonstrated medically significant weight loss and low body weight, but developments in the field have begun to change this perception. Many people in larger bodies still experience the behavioral and psychological markers of AN (sometimes called atypical anorexia), and should be taken seriously in their experiences. Regardless of body weight and shape, AN may lead to additional medical complications, such as amenorrhea (loss of menstrual cycle), fatigue, muscular atrophy, digestive complications, orthostatic vitals, osteoporosis, cardiac complications, and more.
AN has two subtypes:
- Restricting Type – body changes are achieved primarily through dieting, fasting, and/or excessive exercise
- Binge-Eating/Purging Type – the individual has also engaged in recurrent episodes of binge eating or purging behavior (e.g., self-induced vomiting, misuse of laxatives/diuretics) during the current episode
Bulimia Nervosa (BN)
Bulimia Nervosa (BN) can be difficult to distinguish from the Binge-Eating/Purging type of AN. BN’s core features are marked by recurrent episodes of binge eating (consuming an unusually large amount of food in a discrete period with a sense of loss of control) followed by recurrent compensatory behaviors to prevent weight gain. Compensatory behaviors are a form of weight control meant to offset food intake, and can look like self-induced vomiting, misuse of laxatives, diuretics, or other medications, fasting, excessive exercise, and other methods. AN:BE/P is recognized primarily by purging behaviors, sometimes reinforced by binge eating, whereas BN requires the recurrent presence of bingeing for diagnosis.
Common signs of BN can look like evidence of binge eating, frequent trips to the bathroom after meals, dental erosion, electrolyte imbalances, and gastrointestinal problems.
Binge-Eating Disorder (BED)
Binge-eating disorder (BED) is the most common eating disorder in the United States (Berkman et al., 2015). It is defined by recurrent binge-eating episodes (similar to bulimia) without the regular use of compensatory purging, fasting, or excessive exercise. One of the key emotional markers of BED severity is marked distress, including feelings of guilt, shame, and disgust about the amount or type of food consumed.
A binge is characterized in part by eating rapidly, eating until uncomfortably full, eating large amounts when not physically hungry, and eating alone due to shame or embarrassment. It should be noted that, like other eating disorders, BED is not inherently defined by body weight or shape, though it is often met with additional stigma due to culturally reinforced fatphobia and diet culture.
Avoidant/Restrictive Food Intake Disorder (ARFID)
Avoidant/Restrictive Food Intake Disorder (ARFID) is a newer diagnosis, and still in the process of being well-defined. Its core features include a lack of interest in eating or avoidance of food based on its sensory characteristics (e.g., texture, smell, color) or due to a distressing experience (e.g., choking, vomiting), leading to significant nutritional deficiency, weight loss, or psychosocial impairment. One of the main differences between ARFID and other eating disorders is that it is often not accompanied by concerns about body weight or shape.
ARFID is often comorbid (meaning “likely to appear in combination”) with autism and ADHD (Sader et al., 2025). It is also overrepresented in populations with trauma histories (Brewerton et al., 2025). Commonly, it may present as extremely picky eating that persists beyond childhood, limited accepted foods, nutritional deficiencies, dependence on nutritional supplements, and significant anxiety around new foods.
Other Specified Feeding or Eating Disorder
If you have read the criteria of each disorder so far, you may wonder what happens when someone’s relationship with food does not fit cleanly into one set of symptoms. OSFED is considered a category for serious eating disturbances that cause significant distress and impairment but do not meet the full diagnostic criteria for the disorders above.
This may mean not quite meeting the necessary criteria for one specific disorder (though this may also indicate assessment for more general disordered eating), or it may mean that the present symptoms appear to fall under multiple eating disorder subtypes.
For example, perhaps an individual demonstrates the sensory difficulties of ARFID, with the anxiety about body weight of AN.
Note: this does not mean that OSFED is inherently less serious than other eating disorders. It simply indicates that our current understanding of eating disorder categories leaves room for improvement and nuance.
Conclusion
Eating disorders are diverse, and their subtypes manifest in distinct ways, each with potentially serious outcomes. Recognizing the differences between these subtypes can help break stereotypes, reduce stigma, and encourage individuals to seek help even if their experience doesn’t fit a “textbook” image.
Eating disorders can be incredibly powerful, but they can also be understood and treated. Proper intervention can help not only with physical rehabilitation, but also with developing a new way of life that incorporates space for joy and meaning far beyond food. If you recognize yourself or a loved one in any of these descriptions, consider reaching out to a healthcare provider like a doctor or therapist specializing in eating disorders.
Future articles will discuss how to gauge level of care needs.
Thank you for reading, and take care.
References
Auger, N., Potter, B. J., Ukah, U. V., Low, N., Israël, M., Steiger, H., Healy-Profitós, J., & Paradis, G. (2021). Anorexia nervosa and the long-term risk of mortality in women. World Psychiatry: Official Journal of the World Psychiatric Association, 20(3), 448–449.
https://doi.org/10.1002/wps.20904
Berkman ND, Brownley KA, Peat CM, et al. (2015). Management and Outcomes of Binge-Eating Disorder. Agency for Healthcare Research and Quality (U.S.).
Sader, M., Weston, A., Buchan, K., Kerr-Gaffney, J., Gillespie-Smith, K., Sharpe, H., & Duffy, F. (2025). The co-occurrence of autism and avoidant/restrictive food intake disorder (ARFID): A prevalence-based meta-analysis. The International Journal of Eating Disorders, 58(3), 473–488.
https://doi.org/10.1002/eat.24369
Brewerton, T. D., Suro, G., Fernandez, N., Tulga, K., Gavidia, I., & Perlman, M. M. (2025). Avoidant restrictive food intake disorder, traumatic events, and PTSD in adolescents and adults admitted to residential treatment. Journal of Psychiatric Research, 187, 174–180.
https://doi.org/10.1016/j.jpsychires.2025.05.022
