Atypical anorexia diagnosis? Handle with care!

Last updated on September 1st, 2023

What is atypical anorexia?

Has your child been diagnosed with 'atypical' anorexia nervosa?

Discovering your child has an eating disorder is a shock, so first I want to reassure you: an expert in eating disorders should deliver excellent treatment towards complete recovery.

Have a read, and if you're not sure your child is getting competent treatment for atypical anorexia nervosa, this page guides you to ask important questions.

Atypical anorexia: 'Your weight is normal'

Atypical anorexia nervosa is one of the diagnostic categories in the DSM-5 diagnostic manual. Put simply, it's the same as anorexia nervosa except that right now, the person doesn't look horribly thin.

I'll show you how that can, in places, give a false sense of safety and lead to poor treatment and poor recovery. That way you can make sure your child gets great treatment.

Criteria for anorexia and for atypical anorexia nervosa

For a diagnosis of anorexia nervosa:

one of the criteria is :

"Restriction of energy intake relative to requirements, leading to a SIGNIFICANTLY LOW BODY WEIGHT in the context of age, sex, developmental trajectory and physical health. Significantly low weight is defined as a weight that is less than minimally normal or, for children and adolescents, less than that minimally expected."


For a diagnosis of atypical anorexia:

 “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.”


So you see, it's all about 'normal' — normal today, right now.

Atypical anorexia nervosa is one of the OSFED categories in the DSM-5 diagnostic manual: ‘Other Specified Feeding or Eating Disorder

Atypical anorexia: common, and no less serious

Why do so many experts want the 'atypical' diagnosis to be scrapped?

  • The term 'atypical anorexia' might make people think the eating disorder is … not typical. It might mean this field gets less attention. Yet atypical anorexia is very typical. It's more common than the illness diagnosed as anorexia nervosa.
  • And 'atypical' makes it sound less serious, right? Yet it can be very serious, both physically and mentally. It needs treatment to the same standard, with the same level of expertise, as anorexia.

What's considered a 'normal' weight in the definition of atypical anorexia?

The 'normal' range is what an internet calculator brings up when you plug in height, weight, sex and age.

So it's a statistical measure, not one relating to your child as an individual.

I have a very tall friend — the kind of guy who stoops to go through doorways. Clearly not 'normal' statistically. Imagine a scenario where one morning he wakes up realising he's shrunk to average height. There'd be a few investigations, right? Even though his height is now weirdly 'normal'.

All this to say, your child's needs are individual (I collected lots of quotes from top experts here) — statistics is for big populations studies. Sometimes statistics gives us a decent ballpark, but sometimes it's way off, as I show in this YouTube or on this page 'Is your child’s target weight a gift to the eating disorder? One-Size-Fits-All versus Growth Charts'.

Is 'the normal' weight range normal for YOUR child?

Did your child undergo 'significant weight loss'? Because that's part of the diagnosis for atypical anorexia. Perhaps it was actually an enormous amount? Did they lose it over years of restricting, or did they lose it at terrifying speed?

And when you read the signs and symptoms of anorexia nervosa, the anxieties and distorted beliefs and obsessive behaviours, does that pretty much describe your child?

So your child will get the 'atypical anorexia' diagnosis, because their weight is not currently 'significantly low'. Even though it's terribly low for them as an individual.

How much weight loss is 'significant weight loss'?

'Significant weight loss' is not defined in the diagnosis for atypical anorexia nervosa.

You might for instance hear that because your child 'only' lost 5% of their weight, there is no cause for concern, and no diagnosis. Someone might make the additional point that your child is currently of 'normal' weight or more. However if your child is showing mental (cognitive) symptoms, there is evidence that even 'just' a 5% loss should raise alarm:

From a study by Forney et al (2017):

"Results support that even a 5% weight loss, combined with cognitive concerns, may produce a group with a clinically significant eating disorder. Atypical Anorexia Nervosa was observed in both healthy weight and overweight/obese adults, highlighting the importance of screening for restrictive eating disorders at all weights."

Forney et al (2017)

What emerges from this study is that weight suppression of 5% or more is associated with the mental signs and distress that are the hallmarks of an eating disorder. Note that the researchers did not look at levels below 5%, and that this was for adults.

In my page on weight suppression I show the example of a girl who stayed the same weight between ages 10 and 11. So she dropped off her percentile curve, which is a weight loss of 12%.

(Even though I show charts and numbers, please remember that with human growth, there are very few certainties, as explained here).

Girls growth chart- No weight gain - suppression - anorexia ARFID
This girl's weight may be normal statistically, but it's effectively dropped by 12%

What about 'developmental trajectory'?

I get confused by the diagnostic manual. Because in the definition of anorexia, we have 'significantly low body weight in the context of […] developmental trajectory and physical health'. So if a child's BMI is currently 'normal' or higher for their age and sex, but it's shot down in terms of 'developmental trajectory' (such as failure to gain weight when you're a growing child) and if their physical health is poor, then personally I'd argue we have ticked the boxes for anorexia, as well as for atypical anorexia.

What about weight that is 'for children and adolescents, less than that minimally expected"

Another thing that confuses me about the definition of anorexia nervosa, is that for children and adolescents, is includes weight that is 'less than that minimally expected'. Well, we expect children to grow and to keep tracking on their weight percentile curves. Any drop from that is less than expected. So a child who has lost weight doesn't need the 'atypical' diagnosis. It's anorexia.

What's the problem, if the person isn't emaciated?

When someone looks terribly thin, it's easy to guess there might be a problem. In every other situation, we may sleepwalk into assuming they're fine. That's why clinicians must be made aware of the amount and speed of weight loss, and do medical checks.

I say more on my page on 'weight suppression':

* How much weight did your child lose? Weight suppression is crucial in eating disorder diagnosis and treatment */

The danger can get missed if a clinician has their eyes glued to a calculator that registers the person's BMI as normal. The danger is missed even more easily when the person's BMI is currently in the 'overweight' or more categories. Some clinicians have learned this shortcut and not paused to question it:

  • 'normal' or low-ish BMI = great, well done!
  • high BMI = you must surely be unhealthy and should lose weight until my calculator tells me you're healthy

By now you probably know how toxic it is for your child to be praised for their obsessive weight loss, food restriction and over-exercising. There's extra danger if a clinician is so reassured by the current BMI that they assume your child is healthy.

We might even miss that a child is weight suppressed. Consider a young person who has gained a pretty average amount of weight over a year, but actually they were restricting at a time they were due a growth spurt.

It doesn't help, of course, that with an eating disorder our children can put on a GREAT show of health and happiness while talking with a clinician. So a doctor may fail to conduct the required medical examinations, and may not ask you about symptoms.

And then, they do harm by telling you, and your child, that there's no need to regain any lost weight.

With expert clinicians, this won't happen, but there may still be a fight: people may be denied treatment via their medical insurance, or by the national health service… because they're not (yet) thin.

"I am fine!"

People with anorexia tend not to recognise they have a problem. It's called 'anosognosia' and it's part of the glitch in the brain. Also, they get short-term soothing from their behaviours (the illness is 'egosyntonic').

When these individuals see their weight is 'normal' or higher, they're even less likely to recognise that they have anorexia. 'Hey, I'm hardly thin! Have you seen my BMI?!' So they don't look for eating-disorder help. Indeed what they're looking for is how to make their weight-loss diet 'more effective'.

And then sometimes a person with an eating disorder does consult a doctor, or gets dragged in by their parents, and too many leave with their distorted thoughts strengthened: 'I'm not thin enough to be ill, I'm not thin enough to get help'.

For all these reasons, parents, partners, friends and clinicians should recognise anorexia, irrespective of the person's current weight.

The issue is weight suppression

I say more about the dangers of weight suppression here. Weight suppression is how much weight the person lost. And because a child or teen should be growing and gaining weight all the time, we include in 'weight suppression' how much their weight should have gone up, during the time they were losing weight.

To be clear, if a child has lost weight, they are weight-suppressed.

And if another child weighs the same today as last year, they are also most likely weight-suppressed.

Atypical anorexia: rushed to hospital with a normal BMI

We parents know from experience how very ill our child can be from weight loss — and that is true with kids who look emaciated, and with kids who look normal or large.

So if your child has lost a lot of weight, make sure they get proper medical checks. See for instance the MEED (Medical Emergencies in Eating Disorders) guidelines for the UK, and the AED 'purple booklet': Academy for Eating Disorders Guide for Medical Management of eating disorders for the US.

Of course, if someone's weight is very low, their body is probably malfunctioning. But the same medical attention is needed for those who have lost a considerable amount of weight. Here are some papers:

"the extent of physical compromise reported here in adolescents with atypical AN, who are by definition not underweight, suggests that beyond the effects of underweight, substantial loss of weight and/or rapid weight loss may itself be detrimental to physical health”

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

So it's not the current weight, but the weight history, that predicts physical risk:

"In adolescents with restrictive EDs, total weight loss and recent weight gain were better predictors than admission weight of many physical complications"

Whitelaw, M., Lee, K. J., Gilbertson, H., & Sawyer, S. M. (2018). 'Predictors of Complications in Anorexia Nervosa and Atypical Anorexia Nervosa: Degree of Underweight or Extent and Recency of Weight Loss?'. The Journal of adolescent health : official publication of the Society for Adolescent Medicine

This is echoed in this study of 12 to 24-year-olds:

"Patients with large, rapid, or long-duration of weight loss were more severely ill regardless of their current weight"

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'

and as explained in an interview about the study:

"The study found that female atypical patients were just as likely as their underweight counterparts to stop menstruating, a hallmark of hormone suppression due to poor nutrition that impacts fertility and bone density. Both typical and atypical patients were susceptible to electrolyte imbalances […] which can impact the brain, muscles and heart functioning."

Mentally worse off

The above study highlighted another reason to take 'atypical' anorexia very seriously: the patients' mental state — their psychopathology:

"The reproducible finding that patients with Atypical Anorexia Nervosa have worse Eating Disorder psychopathology continues to dispel the misconception that AAN is a lesser illness than AN"

This emerged from scores in the Eating Disorder Examination Questionnaire, a tool that looks at 'avoidance of food and eating, preoccupation with calories and eating in secret, feelings of fatness and discomfort seeing one’s body, dissatisfaction with weight and reaction to being weighed'. The 'atypicals' scored significantly worse.

The treatment should be the same

When you get diagnosed with 'atypical' anorexia, you may get treated rather differently, because people aren't alarmed about your weight, even though they should be.

For example, adults with atypical anorexia, after spending time in residential treatment, may report being fed smaller portions than people with anorexia. Recovering lost weight was not on the agenda, and this confirmed their belief that eating-disorder behaviours are only frowned upon if you're skin and bones.

The NICE guidelines for eating disorders (these are official guidelines for England, based on in-depth reviews of the evidence) require any OSFED (‘Other Specified Feeding or Eating Disorder’), including atypical anorexia, to be treated the same as the illness they most resemble.

In other words, we have to treat atypical anorexia the same as anorexia and not let current body shape lure us into complacency. I look forward to the day those guidelines are followed everywhere and this page becomes unnecessary.

Lost weight should be regained

The experiences of parents and clinicians coincide with the indications from research: if a person with an eating disorder lost weight, it's irrelevant whether their BMI is currently high or low: they need weight gain without delay.

You can leave to later discussions about a weight target — there is no rush, and in any case all goal weights need to be revised and adjusted. Some excellent clinicians argue against giving a target: keep doing the recovery work, and you'll know your child is well when they're well.

Our children can get very focused on weight, and as parents we need to find some peace around all the uncertainties. When the person's weight was particularly high before it started dropping, it's especially important that as a parent, you should feel safe and heard in your weight discussions with clinicians. The same if you're posing questions in parent support groups. For more on the many factors that are considered in estimating how much weight gain your child might need, see my page 'Weight-restoration: why and how much weight gain?

Where's the science?

I encourage you to watch a talk by eating-disorders psychologists Kiera Buchanan and Audrey Raffelt: 'Atypical anorexia or weight stigmatised anorexia?' This is a presentation they made at the ICED 2022 conference.

The authors take you through the evidence, study after study, illustrating each step with the examples of two girls, one with anorexia nervosa, the other with atypical anorexia nervosa:

  • Amelia was diagnosed with anorexia after a huge weight loss resulting in a low BMI.
  • Sophie lost the same amount of weight, in the same amount of time. As she had a high BMI before losing weight, her BMI is now in the 'normal' range. That's the only difference between the two girls.

In the video you'll see how these girls are treated very differently, and how badly Sophie comes out of it. Watch it for the example, as well as for the systematic presentation of the science.


The following pages of mine will help you understand how clinicians may be setting weight targets, and the rationales — good and bad.

My main page on weight restoration
Weight-restoration: why and how much weight gain? *

and also:
* Experts say, "Recovery weight must be individualized" *
* How much weight did your child lose? Weight suppression is critical in eating disorder diagnosis and treatment *
Weight gain in growth spurts *
Weight centile growth charts: why they can’t predict your child’s recovery weight *
* My YouTube: Growth charts and goal weights made simple *
Is your child's target weight a gift to the eating disorder? *
What do BMI and Weight-For-Height mean? *
* My YouTube: What is a BMI or '% Weight-for-Height' target, and how wrong it could be *

And more:

* More on weight and feeding in Chapter 6 of my book and in my Bitesize audio collection *

More reading on atypical anorexia

Lauren Muhlheim's concise overview: Help for Atypical Anorexia:

and When Eating Disorder Providers Are Steeped in Diet Culture:

Walsh, B. T., Hagan, K. E., & Lockwood, C. (2022). A systematic review comparing atypical anorexia nervosa and anorexia nervosa. International Journal of Eating Disorders, 1– 23.

Golden, N. H. (2022). Atypical Anorexia Nervosa is not atypical at all! Commentary on Walsh et al. (2022). International Journal of Eating Disorders, 1– 2.

Harrop, E. N. (2022). A lived experience perspective on the classification of atypical anorexia nervosa. International Journal of Eating Disorders, 1– 2.

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