Text Link

Learn more about the results we get at Within

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse varius enim in eros elementum tristique. Duis cursus, mi quis viverra ornare, eros dolor interdum nulla, ut commodo diam libero vitae erat. Aenean faucibus nibh et justo cursus id rutrum lorem imperdiet. Nunc ut sem vitae risus tristique posuere.

Learn more about the results we get at Within

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse varius enim in eros elementum tristique. Duis cursus, mi quis viverra ornare, eros dolor interdum nulla, ut commodo diam libero vitae erat. Aenean faucibus nibh et justo cursus id rutrum lorem imperdiet. Nunc ut sem vitae risus tristique posuere.

What is atypical anorexia nervosa?

No items found.
No items found.

While atypical anorexia nervosa (AAN) may share characteristics of anorexia nervosa (AN), it is an entirely different diagnosis found in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Atypical anorexia nervosa is categorized in the DSM-5 as an Other Specified Feeding or Eating Disorder (OSED). (1)

 minutes read
Last updated on 
January 30, 2023
In this article

What is atypical anorexia nervosa?

Atypical anorexia nervosa is a term that refers to certain cases of anorexia nervosa that do not follow the established pattern. Generally speaking, most atypical anorexia nervosa cases meet all the criteria of AN, with the exception of a low body weight. 

Some studies suggest that the prevalence of this condition lies around 13% for those identifying as female and 4.9% for those identifying as male, but this eating disorder affects all genders. (3)

For patients suffering from anorexia, one of the primary criteria for diagnosis is a significant weight loss. However, for those suffering from atypical anorexia nervosa, significant weight loss may not be present at all. At least not in the quick fashion that makes it so noticeable with those suffering from traditional AN.

Diagnosing atypical anorexia nervosa

Atypical anorexia nervosa is a newer diagnostic category for eating disorders in the DSM-5, so careful diagnosis is a critical part of proper healing. 

To correctly diagnose atypical anorexia nervosa, there are a few things that the clinician needs to take into account. While unexplained or severe weight loss should be a quick indicator that a patient may be suffering from anorexia, the body weight alone may not be definitive.

Other criteria that you will need to take into account when diagnosing atypical anorexia nervosa include: (1)

  • Skipping meals or taking smaller portions of food
  • Being uncomfortable with eating in front of others
  • Drinking excessive amounts of water or non-caloric beverages
  • Showing extreme concern with their body weight and shape
  • Experiencing stomach cramps, other non-specific gastrointestinal complaints

Should you or a loved one fit into any of the above descriptions, they should be evaluated by a mental health professional or physician. However, even if they do not fit into the profile of someone with anorexia, this does not mean that they are not experiencing the symptoms associated with OSFED.

In diagnosing atypical anorexia nervosa, an individual's weight may be considered part of the evaluation process. However, someone suffering from atypical anorexia nervosa will more likely present with a significant weight loss over a more extended period than a sudden drop in weight. 

However, if an individual meets any of the below-mentioned criteria, though are not considered underweight, they are more likely to receive a diagnosis of atypical anorexia nervosa: (4)

  • Restricting food intake relative to the energy needs of the individual
  • Presenting a fear of gaining weight or of being perceived as overweight 
  • Having a distorted self-image
  • Severely criticizing their body shape or weight
  • Being in denial about the severity of their condition.

Atypical anorexia nervosa signs & symptoms

The American Psychiatric Association has defined the following signs and symptoms for the disorder: (1)

Emotional and behavioral 

  • Dressing in layers to hide weight loss or stay warm
  • Being preoccupied with weight, food, calories, fat grams, and dieting
  • Refusing to eat certain foods, progressing to restrictions against whole food categories
  • Making frequent comments about feeling "fat" or overweight despite weight loss
  • Developing food rituals 
  • Skipping meals or taking small portions of food at regular meals 
  • Drinking excessive amounts of water or non-caloric beverages 
  • Maintaining excessive, rigid exercise regimen


  • Fluctuations in weight
  • Dizziness 
  • Fainting/syncope 
  • Sleep problems 
  • Dry skin 
  • Poor wound healing 
  • Impaired immune functioning 

Effects of atypical anorexia nervosa

The effects of atypical anorexia nervosa may result in the following: (7)

Short-term effects

Short-term effects of atypical anorexia nervosa may result in several medical problems that can require hospitalization, including: 

  • Cardiac arrhythmias
  • Chest pain
  • Low potassium
  • Low calcium levels
  • Low magnesium levels
  • Low phosphate levels
  • Low blood pressure
  • Low blood cell count
  • Low glucose levels in blood
  • Myocardial infarction
  • Sudden rise in heart rate

Long-term effects

Long-term effects of atypical anorexia nervosa may result in the following medical problems: 

  • Cardiomyopathy
  • Chronic fatigue
  • Cirrhosis
  • Diabetes
  • Degenerative joint disease
  • Death

Related disorders

Since atypical anorexia nervosa doesn't fit into the standard diagnostic category as anorexia, it may be misdiagnosed as one of several other eating disorders, including:

  • Anorexia nervosa (AN): patients with AAN may have the classic picture of anorexia nervosa, which includes extreme body dissatisfaction and what appears to be an inability to gain weight.
  • Bulimia nervosa (BD): patients with AAN may develop ritualistic eating patterns, including binge eating followed by compulsory purging behaviors.
  • Binge eating disorder (BED): patients with AAN may binge eat when they think nobody is watching, although these sessions are rare.
  • Avoidant/restrictive food intake disorder (ARFID): patients with AAN may refuse to eat certain food groups, but may not have weight loss. 
  • Body dysmorphic disorder (BDD): patients with AAN may develop an extreme preoccupation with their appearance, similar to BDD. 

Like many other eating disorders, you may also be suffering from a co-occurring disorder, which is another psychiatric disorder (such as depression or anxiety) that occurs alongside an eating disorder.

When seeking treatment, you must work with your team to treat both your eating disorder and your co-occurring disorder to ensure that you receive the best treatment available and increase your chances of a full recovery.

Atypical anorexia nervosa treatment

Atypical anorexia nervosa can be a very challenging condition to treat. However, with the right support system in place, it is more than accessible. 

It’s important to note any underlying psychological conditions and triggers that may present for atypical anorexia nervosa. For most patients, a holistic approach to treating AAN offers the best chance at recovery. 

Typically, treatment for atypical anorexia nervosa involves a multidisciplinary team – and therapeutic intervention focused on:

  • Behavioral techniques
  • Lifestyle counseling
  • Nutritional counseling
  • Psychotherapy 

Therapies for atypical anorexia nervosa

The following therapies have shown to be effective in the treatment of atypical anorexia nervosa: (8)

  • Cognitive behavioral therapy (CBT)
  • Interpersonal psychotherapy for binge eating disorder (IPT-BED)
  • Simplified dialectical behavior therapy (simplified DBT)

Medications for atypical anorexia nervosa

There are no medications approved for the treatment of atypical anorexia nervosa. However, several medications can be used to help treat the disorder's symptoms, including anxiety and depression medications and supplements to resolve nutritional deficiencies.

It’s vital to note that you should never start taking any medications or supplements without first consulting with your treatment team, as doing so can lead to unwanted side effects.

Understanding atypical anorexia nervosa

Atypical anorexia nervosa, like any eating disorder, should be approached with kindness and compassion for the struggling individual. There is much shame and stigma attached to eating disorders, especially lesser-known classifications like atypical anorexia nervosa. Thus, building a better understanding of AAN is a valuable part of the healing process for people with AAN, and those who love them. 

Living with atypical anorexia nervosa

Atypical anorexia nervosa, like many other eating disorders, has the potential to affect the physical and psychological health of the patient.

The patient is likely to develop certain complications, such as:

  • Gastrointestinal distress
  • Low self-esteem
  • Depression
  • Mental disorders
  • Suicidal ideation

Due to the chronic nature of the condition, it affects the patient's quality of life. Some patients may also develop a loss of social identity, which can lead to isolation. Studies show that 97% of individuals who suffer from an eating disorder also suffer from one or more co-occurring conditions, including: (2)

  • Major depression
  • Obsessive-compulsive disorder
  • Post-traumatic stress disorder
  • Alcohol/substance use disorder

The best way to cope with an illness like atypical anorexia nervosa is to work closely with experienced health professionals. Having someone to talk to about your concerns, and to ask questions, can be extremely reassuring and comforting. 

Other coping mechanisms may include:

  • Group or individual therapy (counseling)
  • Family therapy
  • Nutrition counseling

History of atypical anorexia nervosa

Prior to it’s addition to the DSM-5, atypical anorexia nervosa stood for a “less severe form of anorexia nervosa.” (4) In 2013, the American Psychiatric Association recognized the disorder with its diagnostic category, based on the DSM-5 diagnostic criteria. (5) More recent studies have indicated that patients with atypical anorexia nervosa can be just as medically ill as their peers with anorexia nervosa and can have even greater eating disorder psychopathology, which means the early assessment of atypical anorexia nervosa being “a less severe form of anorexia nervosa” is actually a dangerous misclassification. (8,9)

As we continue to learn about AAN, more understanding and compassion for those struggling with this eating disorder are being established in treatment protocols.

Atypical anorexia nervosa in pop culture

Atypical anorexia nervosa is not often discussed in the media, but people are beginning to learn more about it. 

Pop culture references of eating disorders typically vilify the disorders, as well as those struggling with them. However, instead of scaring the public, many who identify with these characters showcased in books and TV films, such as “Little Miss Perfect,” and “Starving in Suburbia,” feel ashamed of their own condition. Most portrayals serve as nothing more than harmful triggers to those actively struggling. 

Increasing awareness of AAN through thoughtful, accurate representation in film and media will provide a more comprehensive understanding while opening treatment pathways for many who live with this condition.

How to help someone with atypical anorexia nervosa

The best way to help someone with atypical anorexia nervosa is to be there for them and positively influence their lives. It is also helpful to understand the disease and the symptoms that are typically associated with it. If your loved one is suffering from atypical anorexia nervosa, here are a few ways you can help support them:

  • Try to be patient with your loved one: In the early stages of the illness, patients with AAN may be very emotional, withdrawn and may have a hard time communicating with others. 
  • Be supportive: Encourage your loved one to eat and drink things that are normal and healthy for their body. 
  • Don't compare: Everyone is unique and their specific body’s shape and size may vary from yours, while still being healthy. Don't compare your loved one's weight to others and don't try to force them to eat more or less than they are comfortable with. 
  • Don't criticize your loved one's body shape or size: This may actually increase your loved one's feelings of low self-esteem and body dissatisfaction. 
  • Don't control your loved one's food and drink intake: This can make them feel more anxious and insecure. Leave decisions around their nutrition to their treatment team. 

At Within Health we believe in treating each eating disorder personally. If you or a loved one are struggling with atypical anorexia nervosa, or another eating disorder, help is available at your fingertips. Call our admissions team to get started.

Disclaimer about "overeating": Within Health hesitatingly uses the word "overeating" because it is the term currently associated with this condition in society, however, we believe it inherently overlooks the various psychological aspects of this condition which are often interconnected with internalized diet culture, and a restrictive mindset about food. For the remainder of this piece, we will therefore be putting "overeating" in quotations to recognize that the diagnosis itself pathologizes behavior that is potentially hardwired and adaptive to a restrictive mindset.

Disclaimer about weight loss drugs: Within does not endorse the use of any weight loss drug or behavior and seeks to provide education on the insidious nature of diet culture. We understand the complex nature of disordered eating and eating disorders and strongly encourage anyone engaging in these behaviors to reach out for help as soon as possible. No statement should be taken as healthcare advice. All healthcare decisions should be made with your individual healthcare provider.


  1. National Eating Disorders Association. (2018, July 30). Other specified feeding or eating disorder.
  2. National Eating Disorders Association. (2021, July 14). Statistics & research on eating disorders. 
  3. Eating behaviors. (2021, April). Atypical anorexia Nervosa, not so ATYPICAL after ALL: Prevalence, correlates, and clinical severity among United States military veterans. 
  4. American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Washington, DC: American Psychiatric Press
  5. American Psychiatric Association. (2013). Updated Disorders: Eating Disorders.
  6. National Eating Disorders Association. (2018, February 22). Health consequences
  7. National Collaborating Centre for Mental Health (UK). (2004). Treatment and management of atypical eating disorders (eating disorders not otherwise specified) including binge eating disorder. Eating Disorders: Core Interventions in the Treatment and Management of Anorexia Nervosa, Bulimia Nervosa and Related Eating Disorders.
  8. Pediatrics (2016). Physical and psychological morbidity in adolescents with atypical anorexia nervosa.
  9. Pediatrics 2019 (Nov 6). Weight loss and illness severity in adolescents with atypical anorexia nervosa.


Is Atypical Anorexia Nervosa the Same as Anorexia Nervosa?

The two terms are often used interchangeably, but they are not the same. Those with anorexia nervosa experience a great deal of weight loss, a distorted body image, and a fear of gaining weight. People with atypical anorexia nervosa are less likely to appear severely malnourished.

Can Someone Fully Recover From Atypical Anorexia Nervosa?

Yes! With the right treatment team and support system, it is very possible to make a full recovery. Our clinical team at Within Health provides clinically superior continuous care attuned to your specific needs. If you or someone you love is in need of healing for their eating disorder, please reach out to our clinical care team today. 

How do I Know if I Have Atypical Anorexia Nervosa?

If you or a loved one presents with symptoms of an eating disorder, it is important to seek treatment as soon as possible. These symptoms may include:

  • Extreme concern about weight and body shape
  • Excessive dieting
  • Engaging in an unhealthy exercise routine
  • A constant preoccupation with food and eating
  • A fear of gaining weight or becoming fat
  • Lack of interest in eating and/or other activities
  • An inability to maintain a healthy weight

Further reading

Atypical anorexia in men

Men and boys with atypical anorexia may focus on building muscle mass through excessive exercise, weightliftin

About other specified feeding or eating disorders (OSFED)

Other specified feeding or eating disorders (OSFED) was created as a catch-all category to describe conditions

What causes atypical anorexia nervosa?

Atypical anorexia nervosa (AAN) is a serious eating disorder that shares many of...

Signs and symptoms of atypical bulimia nervosa

The signs and symptoms of atypical bulimia nervosa (ABN) are similar to those...

Atypical anorexia nervosa symptoms

Atypical anorexia nervosa (AAN) shares many of the same characteristics as anorexia...

What is purging disorder?

Purging disorder is an eating disorder that involves purging to lose weight or change...

What is night eating syndrome?

Night eating syndrome (NES) is a sleep-related eating disorder where a person eats more food at night than...

How to stop eating at night

Everyone has the occasional late-night dinner or midnight snack, but for some people, overeating at night...

What is atypical anorexia nervosa?

While atypical anorexia nervosa (AAN) may share characteristics of anorexia nervosa...

What is atypical bulimia nervosa?

Atypical bulimia nervosa (ABN) is a form of bulimia nervosa (BN) that affects...

A look into purge eating disorder

Many people are familiar with eating disorders like anorexia nervosa (AN), bulimia nervosa (BN), and binge...

Further reading

No items found.