As an Eating Disorder Psychologist, I Reject the Harmful 'Atypical Anorexia' Diagnosis

Individuals with eating disorders frequently struggle to accept their diagnosis, often due to fears around not being “sick enough", not being more “successful” in their restrictive intake, and not being “thin enough” ⁽⁴⁾

Consequently, in working with individuals with complex and severe eating disorders, a big part of the work is to help them to recognise the eating disorder thoughts and behaviours as significant and as quality of life interfering. Without recognising the severity of the problem, one is not compelled to do the work required for recovery.

Given that a key feature of eating disorders is a fear that one is not “thin enough” - the criteria for Atypical Anorexia Nervosa (AAN) in the Diagnostic Statistical Manual (DSM)-5-TR is at best, insensitive, and at worst, offensive and fat phobic.

Like the criteria of Anorexia Nervosa (AN) individuals with AAN present with:
1. Restrictive eating behaviours
2. Intense fear of weight gain
3. Disturbance in the way in which one’s body weight or shape is experienced and undue influence of body shape and weight on self-evaluation.

The single criteria that differentiates AAN from Anorexia Nervosa (AN) is that the weight criteria of a BMI of 17 or below is not met. In fact, individuals with AAN can have significant weight loss in a short period of time, but if their start weight was in a larger body (and larger here could even mean the higher end of the “healthy” weight range) or their metabolism is compromised, significant weight loss may not lead to a BMI of 17 or below.

Essentially, in the eyes of an individual with an eating disorder, they do not meet the criteria of Anorexia Nervosa because they are not skinny enough.

For individuals with Severe and Enduring Anorexia Nervosa (SEAN) where they have lived with AN for a minimum of 7-10 years, it is typical for their body to adjust to a state of constant malnourishment. Despite a severely restricted intake, they will typically have stable medical observations (such as bloods) and a stable weight. Research shows that a chronically restricted intake leads to a significant drop in the Basal Metabolic Rate (BMR). Essentially, if intake remains minimal, the body attempts to preserve energy and prevent further weight loss by significantly slowing down its energy expenditure. In the Minnesota Semi-Starvation Study in 1944, a daily caloric intake of 1500 across a 5 1/2 month period led to an average BMR drop of 40% ⁽¹⁸⁾.

Individuals with SEAN have been engaging in restrictive intake behaviours for a lot longer than 5 months, and while they may have had a low BMI in the initial years of their disorder, many with SEAN have a BMI deemed “healthy”, and subsequently do not meet the criteria for AN. The DSM-5 defines this presentation as one of ‘partial recovery’ even if there is no improvement in eating disorder cognitions or behaviours. They are in ‘partial recovery’ because their BMR has slowed down preventing them from being at a lower weight. Again, not skinny enough.

It is worth noting that individuals with SEAN, despite having more stable medical observations and weight, are not less likely to die from their illness. In fact, the opposite is true.

Even the use of the word atypical in the AAN diagnosis implies that it is an unusual or less significant presentation. Unfortunately, a commonly held belief in the eating disorder community is that individuals with AN are the real eating disorders, while Bulimia Nervosa (BN), Binge Eating Disorder (BED), and Otherwise Specified Eating Disorders (OSFED, which includes AAN and others), are the less frequent and less serious eating disorders. In the eating disorder community, non-AN eating disorders have even been horrifyingly referred to as “wanarexics” (want-to-be-anorexics). Being known as an eating disorder psychologist, I’ve even had patients express reluctance to book in with me for fear of not being “thin enough” or restrictive enough to warrant treatment from an eating disorder psychologist.

The use of atypical in describing AAN is completely at odds with the fact that less than 6% of individuals with eating disorders are underweight ⁽⁵⁾, and the fact that a study in the Journal of Eating Disorders found that AAN is five times more likely than AN.

The real prevalence of AAN is likely to be even higher due to misinformation and weight stigma leading people with eating disorders who are not underweight to avoid seeking diagnosis and treatment. It appears that Atypical Anorexia Nervosa is not so atypical at all ^{(6) (8)}.

Not only do individuals with eating disorders that are not underweight face weight stigma and discrimination when it comes to diagnosis, they experience it when it comes to treatment as well ^{(3) (4) (7) (9)}. As Rachel Millner (2022) puts it, “The trauma of weight stigma is systemic and seeps into every aspect of our lives including in the therapy room”  ⁽¹²⁾.

Individuals with eating disorders who are not underweight self-report that they receive messages from health professionals that they are not sick enough or thin enough to warrant treatment. This is especially true of individuals in larger bodies. Research has found that individuals who meet the criteria for AAN are frequently guided to lose weight, even if they are experiencing intrusive eating disorder thoughts and behaviours, and even medical complications relating to their eating disorder. It has also been found that healthcare providers generally fail to identify eating disorders in individuals who are not underweight. Furthermore, healthcare provider weight stigma has been shown to lead to delays in both diagnosis and treatment of individuals with eating disorders who are not underweight and even instances of health care providers triggering eating disorder thoughts and behaviours in their patients that resulted in health risks ⁽⁷⁾.

In support of this finding, one vignette study indicated that mental health trainees are significantly more likely to diagnose underweight patients with an eating disorder compared to those with a BMI of 20 or above that present with the same symptoms. Patients that were not underweight were also recommended fewer therapy sessions than underweight patients ⁽¹⁶⁾.

Another vignette study found that patients with AAN were viewed by the participants through a stigmatised lens compared to the patients with AN, for example, patients with AAN were perceived to have significantly more control over their eating disorder than those with AN ⁽³⁾.

In a qualitative study on Family Based Therapy (FBT), health professionals reported that eating disorder treatment often sends “mixed messages” to patients with AAN - on the one hand telling them that they may need to gain weight for recovery, while on the other hand sending messages about weight loss and preventing weight gain ⁽¹⁰⁾.

These mixed signals are reflective of a fat-phobic society, sending a message to vulnerable individuals with a distorted body image that is synonymous with - get better, just don’t get fat.

This weight stigma/fat phobia is further reflected by the fact that the medical community generally views Anorexia Nervosa as distinct from other forms of eating disorders due to the presence of starvation syndrome, it being both a physical and mental illness, and it being the deadliest psychiatric disorder ^{(1) (11) (14) (15) (17)}.

Individuals with AAN may not look like they are at risk of dying, but research indicates that they experience life-threatening medical complications as a result of their eating disorder at rates similar to those with AN. For example, individuals with AAN experience electrolyte imbalance, bradycardia, hypothermia, and orthostasis, at roughly the same rate as AN patients, despite their weight being higher. The only identifiable difference between the two medically was that AAN patients were less impacted by amenorrhea and bone density than AN patients ^{(1) (11) (14) (15) (17)}.

While individuals with AAN experience physiological complications related to their eating disorder behaviours similar to those with AN, when it comes to eating disorder specific psychopathology, research indicates that individuals in a larger body present with more severe psychological symptoms than those with a lower BMI ^{(4) (11) (14)}. This could be, in part, due to the finding that a lower minimum BMI is associated with less treatment delay and a higher maximum BMI is associated with lower levels of care received. In a qualitative study, patients with AAN report that weight stigma from their healthcare providers contributed to both the initiation of disordered eating and the perpetuation of eating disorder thoughts and behaviours ⁽⁷⁾.

Finally, individuals with eating disorders may be particularly prone to messaging that they are not sick enough not only due to their eating disorder cognitions, but also due to the black-and-white or rigid thinking patterns often associated with starvation syndrome, co-occurring presentations such as autism, or comorbidities such as anxiety, depression, and trauma. Individuals who are turned away from treatment due to their weight not being low enough may restrict their food and fluid intake, increase exercise or purging behaviours etc., in an attempt to be taken seriously ^{(2) (4)}.

In summary, Atypical Anorexia Nervosa is an unnecessary and unhelpful distinction from Anorexia Nervosa as:

1. The single distinguishing feature is weight
2. The focus on weight is particularly distressing to individuals with eating disorders given that pre-occupation with wanting to lose weight and not feeling thin enough is a key feature of the illness
3. Atypical AN is not atypical at all, with the vast majority of individuals with restrictive eating disorders being in a body that is not underweight
4. The stigma associated with AAN (and it not being real anorexia) perpetuates weight stigma and is associated with diagnosis and treatment delays and lower quality of treatment
5. The medical complications of AAN are on par with the medical complications of AN
6. The eating disorder specific psychopathology of AAN appears to be higher compared to those with AN (possibly due to stigma and delays in treatment/inadequate treatment)
7. Black and white and rigid thinking associated with starvation syndrome, autism, and psychiatric comorbidities make the weight distinction particularly distressing to individuals with an eating disorder who do not meet the arbitrary weight cut-off, possibly leading to an increase in eating disorder behaviours in an attempt to be taken seriously
   

In the words of Laurence Cobbaert and Anna Rose from Eating Disorders Neurodiversity Australia, "Atypical Anorexia Nervosa can be interpreted literally as a judgement of an individual’s ability to achieve an arbitrary weight”  ⁽²⁾ .

At Exhale Psychology Centre, we are committed to reducing weight stigma and improving care. We use a Health at Every Size (HAES) approach, focusing treatment on maladaptive behaviours rather than weight.

Lucy Smith
Director and Psychologist

References and Recommended Reading

1. Brennan, C., Illingworth, S., Cini, E., Bhakta., E. (2023). Medical Instability in Typical and Atypical Adolescent Anorexia Nervosa: A Systematic Review and Meta-Analysis. Journal of Eating Disorders, 11:58.

2. Cobbaert, L., & Rose, A. (2023). Eating Disorders and Neurodivergence: A Stepped Care Approach. Work commissioned by the National Eating Disorders Collaborate (NEDC).

3. Cunning, A., & Rancourt, D. (2023). Stigmatization of Anorexia Nervosa Versus Atypical Anorexia Nervosa: An Experimental Study. Journal of Stigma and Health. Advance online publication.

4. Eiring, K., Hage, T.W.. & Reas, D.L. (2021). Exploring the Experience of Being Viewed As “Not Sick Enough”: A Qualitative Study of Women Recovered From Anorexia Nervosa or Atypical Anorexia Nervosa. Journal of Eating Disorders, Volume 9, Article 142.

5. Flament, M., Henderson, K., Buchholz, A., Obeid, N., Nguyen, H., Birmingham, M., & Goldfield, G. (2015). Weight Status and DSM-5 Diagnoses of Eating Disorders in Adolescents From the Community. Journal of the American Academy of Child & Adolescent Psychiatry, Vol. 54, Issue 5, p403-411.

6. Golden, N.H. (2022). Atypical Anorexia Nervosa Is Not Atypical At All! Commentary on Walsh et. al. (2022). International Journal of Eating Disorders, Vol 56, Issue 4, p826-827.

7. Harrop, E.N. (2020). “Maybe I Really Am Too Fat to Have an Eating Disorder”: A Mixed Methods Study of Weight Stigma and Healthcare Experiences in a Diverse Sample of Patients with Atypical Anorexia. A dissertation from the University of Washington.

8. Harrop, E.N., Mesinger, J.L., Moore, M. & Lindhorst, T. (2021). Restrictive Eating Disorders in Higher Weight Persons: A Systematic Review of Atypical Anorexia Nervosa Prevalence and Consecutive Admission Literature. International Journal of Eating Disorders, Vol 54, Issue 8, p1328-1357.

9. Harrop, E.N., Hutcheson, R., Harner, V. Mensinger, J.L., & Lindhorst, T. (2023). “You Don’t Look Anorexic”: Atypical anorexia patient experiences of weight stigma in medical care. Journal of Body Image, Volume 46, p48-61.

10. Kimber, M., Dimitropoulos, G., Williams, E.P., Singh, M., Loeb, K.L., Hughes, E.K., Garber, A., Elliott, A., Vyver, E., & Le Grange, D. (2019). Tackling Mixed Messages: Practitioner Reflections On Working With Adolescents With Atypical Anorexia and Their Families. Journal of Eating Disorders, Volume 27, Issue 5, p436-452.

11. Matthews, A., Kramer, R.A., & Mitan, L. (2022). Eating Disorder Severity and Psychological Morbidity in Adolescents With Anorexia Nervosa or Atypical Anorexia Nervosa and Premorbid Overweight/Obesity. Eating and Weight Disorders, Vol 27, Issue 1, p233-242.

12. Millner, R. (2002). How the Trauma Field is Traumatising Higher Weight People. Blog Post. https://www.rachelmillnertherapy.com/blog/874947-how-the-trauma-field-is-traumatizing-higher-weight-people

13. Millner, R. (2002). Why Aren’t We Having More Nuanced Conversations About eating Disorders. Blog Post. https://www.rachelmillnertherapy.com/blog/787116-why-arent-we-having-more-nuanced-conversations-about-eating-disorders

14. Peebles, R., Hardy, K.K., Wilson, J.L., & Lock, J.D. (2010). Are Diagnostic Criteria for Eating Disorders Markers of Medical Severity? Journal of Pediatrics, Vol 125, Issue 5.

15. Sawyer, S.M, Whitelaw, M., Le Grange D., Yeo, M. & Hughes, E.L. (2016). Physical and Psychological Morbidity in Adolescents With Atypical Anorexia Nervosa.

Journal of Pediatrics. Volume 137, Issue 4.

16. Viellette, L.A.S., Serrano, M., & Brochu, P.M. (2018). What’s Weight Got To Do With It? Mental Health Trainee’s Perception of a Client with Anorexia Nervosa Symptoms. Frontiers in Psychology, Section Eating Behaviour. Volume 9.

17. Walsh, T.B., Hagen, K.E. & Lockwood, C. (2022). A Systematic Review Comparing Atypical Anorexia Nervosa and Anorexia Nervosa. International Journal of Eating Disorders, Vol. 56, Issue 4, p798-820.

18. The Effects of Starvation Behaviour (Download PDF)

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