Atypical anorexia nervosa (AAN) is a condition where a person has the typical signs and symptoms of anorexia nervosa. However, their weight remains within or above the medically defined healthy range.

As individuals with AAN are not within the underweight range, doctors may not immediately detect the condition, posing significant challenges for diagnosis and treatment.

However, people with AAN demand the same degree of support and therapy as those with more conventional presentations. They are still at risk for the same challenges and complications as those with typical anorexia.

This article explores AAN, its symptoms, and treatment.

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AAN is a relatively recent classification of eating disorders introduced in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition, text revision (DSM-5-TR). It falls under the category of Other Specified Feeding or Eating Disorders (OSFED).

Before the introduction of this specific classification, many individuals who exhibited signs and symptoms of anorexia nervosa but did not meet the weight criterion were often undiagnosed or misdiagnosed.

Although the person has a body mass index at or above the healthy range, they still experience the same characteristics of anorexia nervosa, such as distress, body dissatisfaction, and fear of gaining weight. They may also experience significant weight loss, but people can often overlook it because they started at a higher weight.

Individuals with AAN may exhibit a range of symptoms consistent with anorexia nervosa. These include:

  • an intense fear of gaining weight
  • distorted body image
  • engaging in behaviors to prevent weight gain, such as excessive exercise, extreme dietary restrictions, or purging
  • preoccupation with food, dieting, and body size
  • physical signs such as dizziness or fatigue
  • irregular or no periods

While AAN and anorexia nervosa share many psychological and behavioral characteristics, there is a crucial distinction between them.

In anorexia nervosa, the individual’s weight drops below the medically defined healthy range. Conversely, individuals with AAN maintain a weight that is either within or above this range.

This weight criterion often causes misunderstandings and misdiagnoses between the two conditions.

Eating disorders — including AAN — arise from a combination of genetic, psychological, and environmental factors. Some recognized triggers and risk factors include:

  • genetic predisposition or a family history of eating disorders
  • societal pressures emphasizing thinness or a specific body type
  • psychological factors, such as perfectionism
  • traumatic events or experiences, such as bullying related to weight or body image

Doctors often find diagnosing AAN more challenging than diagnosing anorexia nervosa. Common stereotypes and misconceptions about eating disorders can introduce biases, delaying or even missing a diagnosis.

Individuals with AAN may experience malnutrition, psychological symptoms, and severe health issues after weight loss.

Delayed treatment often results in inferior treatment outcomes. Therefore, doctors must perform a comprehensive assessment, including medical history, physical examination, and psychological evaluations, to diagnose the condition accurately.

Effective treatment for AAN combines several approaches tailored to the individual’s needs. These might include:

  • Nutritional counseling: Helping individuals establish healthy eating patterns and correcting misconceptions about food and weight.
  • Psychotherapy: Cognitive-behavioral therapy (CBT) is often effective in addressing distorted body image and unhealthy behavior patterns.
  • Medication: Some individuals benefit from antidepressants or antianxiety medications to address underlying mood disorders.
  • Support groups: Peer support can provide understanding and coping strategies for people who have experienced similar challenges.
  • Regular medical monitoring: A healthcare team can track any potential physical complications or changes in mental health with a regular schedule of appointments.

Treatment for AAN is especially challenging as the individual has three issues to contend with:

  • physical recovery from malnutrition triggered by significant weight loss
  • psychological recovery from the eating disorder
  • the medical complications of overweight or obesity

Given the complexity of eating disorders, a multi-disciplinary approach involving mental health professionals, dietitians, and primary healthcare professionals will often yield the best results.

Navigating the complexities of AAN is less challenging when a person has a robust support system, both professionally and personally:

  • Professional support: Working with trained therapists or counselors specializing in eating disorders is invaluable. These professionals offer guidance tailored to the unique challenges presented by AAN.
  • Support groups: Joining in-person or online groups provides individuals a platform to share experiences, challenges, and coping strategies. Engaging with peers who understand the nuances of the disorder can foster a sense of community and belonging.
  • Educational resources: Acquiring knowledge about AAN, its origins, and its effects can empower individuals to advocate for their own health. The National Eating Disorders Association is an excellent place to start.
  • Family and friends: Building a supportive environment at home is crucial. Loved ones can educate themselves about AAN to understand and help the person. Open communication helps ensure that those around the individual can recognize signs of distress or relapse.

Support is not one-size-fits-all. Each individual’s journey with AAN is unique, and the support they require may vary based on their specific needs and circumstances.

Although atypical anorexia (AAN) has the same symptoms as anorexia, doctors may overlook it because they maintain a weight within or above the healthy range.

Factors such as genetics, societal pressures, and personal history can contribute to the onset of AAN. Effective treatment combines nutritional guidance, therapy, medications, and ongoing support.

Crucially, fostering a strong support system is vital. This may include professionals, support groups, or friends and family.