Atypical Anorexia Nervosa: Signs, Symptoms & How to Get Help 

By Dennis Gibson, MD, FACP, CEDS

Jasmine had been worried about her weight for as long as she could remember. Teased at school for being “chubby” as a child, Jasmine spent hours each day focused on her appearance in an attempt to look “perfect.” She obsessed over every little thing she ate and tried all the fad diets. By high school, Jasmine was consuming less than 800 calories per day and was using laxatives, diuretics, excessive exercise and other extreme methods to lose weight.  

Jasmine was so good at hiding her eating disorder that no one caught on for years. Even when she started experiencing a number of health consequences (injuries that wouldn’t heal, gastrointestinal issues and more), her family and medical providers were still in the dark about her serious eating disorder. Why? Because Jasmine, despite all of her efforts to become as slim as possible, was still considered “overweight” based on her body mass index (BMI) of 25 kg/m2. 

Since individuals with atypical anorexia nervosa do not appear “alarmingly thin enough” to have an eating disorder, providers do not refer them out for treatment, and their suffering continues for far too long. 


What is Atypical Anorexia Nervosa?  

Atypical anorexia nervosa (A-AN) is an eating disorder that shares many signs and symptoms with anorexia nervosa (AN). The difference between the two is that with A-AN, an individual’s body weight falls within or above the normal range. With AN, one is generally considered to have a low body weight with a BMI less than 18.5 kg/m2. 

The myth that eating disorders are only dangerous when an individual drops to a very low body weight must be corrected. The truth is that eating disorders, and the medical complications that accompany them, affect individuals of every size and body weight.  

When healthcare providers focus solely on underweight individuals as being at risk for eating disorders, millions of individuals with dangerous, distressing eating disorders are overlooked. As a result, people with A-AN do not get the help they need — and the distressing eating disorder psychopathology continues.  


Signs & Symptoms of Atypical Anorexia Nervosa 

Atypical anorexia nervosa is associated with symptoms that worsen as the eating disorder behaviors continue. Similar to other eating disorders, people with A-AN tend to experience a host of concerns around food and body image. Signs of A-AN include:  

  • An intense fear of gaining weight 

  • Restricting calories in order to lose weight 

  • An abnormal focus on body image or body image distortions 

  • Bingeing and purging (self-induced vomiting, diuretics, or laxatives)  

  • Significant, rapid weight loss 

Co-occurring mental health disorders (anxiety, obsessive-compulsive disorder, mood disorders, etc.) are common with A-AN. Self-injury behaviors and suicidal thoughts may also be present. Research demonstrates that adolescents with A-AN can experience more severe eating disorder symptoms than those with anorexia nervosa — along with lower self-esteem. 


Medical Complications of Atypical Anorexia Nervosa 

The medical complications associated with extreme atypical anorexia nervosa can be severe, at times affecting nearly all organ systems. Some individuals with A-AN may experience more serious medical issues compared to individuals diagnosed with anorexia nervosa. Some of the medical complications likely associated with A-AN include: 

  • Menstrual dysfunction 

  • Hormonal changes 

  • Low phosphorous 

With prompt treatment from experienced professionals, many of these complications can resolve and a full recovery is possible.  


Diagnosing Atypical Anorexia Nervosa 

Atypical anorexia nervosa is categorized under other specified feeding and eating disorders (OSFED) in the DSM-5. Since individuals with A-AN fall within or above a normal weight range, providers are wise to screen for any recent, rapid, or massive weight loss in individuals suspected of having eating disorder thoughts or behaviors. Providers should pay attention when a patient: 

  • Loses weight too quickly 

  • Loses too much weight from their natural body weight 

The rate of recent weight loss is poorly defined although some studies suggest that even 5-10% loss of weight from the highest lifetime weight may contribute to these psychologic and medical complications. Other studies suggest a higher percentage of weight loss over 3-6 months is needed to produce these complications.  

Recommended Evaluation: 

  • Full history and physical 

  • Laboratory workup, including complete blood count, complete metabolic panel, and thyroid function panel 

  • EKG to quickly assess cardiac function 

  • DEXA scan to assess bone density, if weight loss has been ongoing for greater than 9 months 


Atypical Anorexia Nervosa: The Overlooked Eating Disorder 

Many people mistakenly believe that A-AN is less serious than AN, despite clinical recognition and case studies demonstrating the seriousness of this eating disorder. Doctors may completely overlook the fact that their patient is miserable and in a vulnerable medical and mental state — simply because the patient does not appear emaciated. 

Sadly, many people struggling with A-AN are assumed not to have an eating disorder because they don’t look underweight. When doctors screen for eating disorders, they may be more likely to overlook eating disorder concerns in patients that appear to be at a healthy weight range or even overweight. This leaves patients with A-AN less likely to be referred out for eating disorder treatment. Insurance companies are also less likely to cover intensive eating disorder treatment for individuals with higher body weights, creating needless suffering. 

Worse, healthcare providers may even recommend or prescribe weight loss to these patients. Further, individuals with A-AN may be praised by friends and family, told they “look great” and given other well-meaning compliments following any visible weight loss — these types of comments can all perpetuate the eating disorder, making the individual even sicker. 

Unfortunately, our society continues to focus on praising any and all weight loss, with most media representations still favoring and highlighting smaller bodies. Thankfully, this is starting to change in recent years as people with diverse, authentic body types are cast in ad campaigns, movies and TV shows.    

However, in recent years, since the publication of the DSM-5, more providers are beginning to refer patients with A-AN out for intensive eating disorder treatment, although it is likely that many of those in the community with A-AN are ultimately not referred to eating disorder specific care. It is estimated that 25-40% of patients admitted to inpatient units have atypical anorexia nervosa, a 5-fold increase in just 5 years.  

Still, too few medical providers are trained in understanding A-AN. Serious complications may be overlooked or excused by an untrained eye, whereas a trained eating disorder expert will be more likely to pursue further questioning and testing for an accurate diagnosis.  


How to Get Help for Atypical Anorexia Nervosa 

Eating disorders affect patients living in a wide variety of bodies. Atypical anorexia nervosa is a life-threatening eating disorder just like anorexia nervosa. Both eating disorders are serious. Providers can make a difference by screening all patients for eating disorders — not just those who appear to be underweight. Should a patient show signs and symptoms of A-AN, providers must refer them out to experienced, effective eating disorder treatment providers. These efforts will save lives and reduce unnecessary suffering. 

ACUTE is the only dedicated inpatient medical stabilization program in the country with the resources, environment and experience to treat the most medically severe cases of A-AN. Helping thousands of individuals recover, all care at ACUTE is overseen by Dr. Philip Mehler, the world’s leading expert in the medical treatment of eating disorders. Everyone deserves a chance to survive and recover — we can help. 


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Dennis Gibson, MD, FACP, CEDS

Dennis Gibson, MD, FACP, CEDS serves as the Clinical Operations Director at ACUTE. Dr. Gibson joined ACUTE in 2017 and has since dedicated his clinical efforts to the life-saving medical care of…

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