What is atypical anorexia?
Blog Post by Contributing Editor Sierra Dayton, M.Ed., LPC
Eating disorders (EDs) are complex, biopsychosocial mental illnesses characterized by severe disturbances in a person's eating behaviors (Harrop et al., 2023). The Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5, 2013) outlines the different ED diagnoses recognized by the American Psychiatric Association and includes anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED). Also included are the lesser-known diagnoses under other specified feeding and eating disorders (OSFED). One of the most common diagnoses under this umbrella is atypical anorexia (AAN). Despite the descriptor “atypical,” AAN is not all that atypical.
What is atypical anorexia?
Atypical anorexia is a diagnosis given to those who meet the criteria for AN, except they do not meet the criteria of “significantly low weight” or, despite significant weight loss, the individual remains at a weight that is considered “healthy” per Body Mass Index (BMI). AAN is also utilized for individuals who meet the criteria for AN but remain in a larger body (Parpia, Spettigue, & Norris, 2023). AAN is estimated to impact between 0.2% and 4.9% of the population (Harrop et al., 2023). In a review of seventy-five studies, researchers found that AAN is, at minimum, as common, if not more common, than AN (Harrop et al., 2021). Despite the high prevalence of AAN, individuals struggling with AAN are less frequently detected and referred to specialized ED care (Harrop et al., 2021).
How does weight stigma influence diagnosis of atypical anorexia?
Weight stigma contributes to the lack of care for individuals with AAN due to weight stigma. Individuals with AAN may be discouraged from seeking medical care, resulting in delayed diagnosis and treatment, which contributes to worsened physical and mental health outcomes (Daley, Ginsburg, & Sheer, 2025). Weight stigma is the result of weight biases (preconceived notions, attitudes, beliefs, and assumptions regarding individuals in larger bodies), which often lead to marginalization, devaluation, and discriminatory behaviors towards individuals in larger bodies (Daley, Ginsburg, & Sheer, 2025).
Individuals with AAN often experience the stereotype that only individuals in smaller bodies can have serious, restrictive EDs, leading to misdiagnosis and underdiagnosis, as healthcare providers often fail to identify ED symptoms in individuals of larger bodies (Freizinger et al., 2022). Studies show that individuals with AAN are less likely to be referred to ED specific treatment, rather they are often referred to “weight management” clinics (Harrop et al., 2021; Kons, Essayli, & Shook, 2023).
Additional stigma is witnessed in the diagnostic process of EDs. Guidelines from the DSM-5-TR base the severity of AN using Body Mass Index (BMI) categories. The guidelines are subsequently utilized by health insurance companies to determine eligibility for higher levels of care (Harrop et al., 2021), which influences continued weight stigma and worsens restrictive eating behaviors in individuals with AAN, as they often end up believing they are not “sick enough” to require treatment (Eiring, Wiig Hage, & Reas, 2021).
The Reality of How Atypical Anorexia Impacts Individuals
More and more research has shown that individuals with AAN experience symptoms of medical instability akin to those who are diagnosed with AN. Rapid weight loss and malnutrition at any size can lead to life-threatening medical complications (Brennan et al., 2023). Additionally, individuals with AAN often exhibit equally severe or more severe psychological symptoms, especially in terms of distress regarding weight and body shape (Walsh, Hagan, & Lockwood, 2022).
Individuals with AAN experience high disturbance of body shape and/or weight and their body shape and/or weight has an abnormally large influence on their self-evaluation. Individuals with AAN are often preoccupied with their food intake, are often highly focused on counting calories, fats, carbs, etc., and frequently engage in dieting behaviors. Just like individuals with AN, individuals with AAN often have an intense fear of weight gain and will often manipulate their eating habits to avoid weight gain or induce weight loss. They often engage in food rituals and behaviors, such as eating foods in a specific order, excessive chewing, counting chews, rearranging foods on their plate, and microbiting). These individuals will often deny feeling hungry and will attempt to avoid meals and situations involving food. Some individuals with AAN may engage in compensatory behaviors, such as self-induced vomiting, diuretic and/or laxative misuse, and periods of fasting or restricting. For individuals who are also diagnosed with diabetes, individuals may manipulate their insulin dosage and timing to try to induce weight loss. They may also engage in excessive, compensatory exercising behaviors and will often ignore fatigue and injuries in favor of continuing to exercise (American Psychiatric Association, 2022; Crone et al., 2023; Fitterman-Harris et al., 2024; Vo & Golden, 2022).
AAN is also notable for significant weight loss. However, despite this weight loss, the individual is still within or above the “normal” range for weight dependent on their BMI. Nonetheless, severe symptoms of malnutrition still occur and these individuals often experience abnormal labs, including anemia, low thyroid and hormone levels, hypokalemia (low potassium), and low blood cell counts. These individuals may also experience dizziness, syncope (fainting), cold intolerance, and menstrual irregularities (primary or secondary amenorrhea) for those who are assigned female at birth (AFAB). Individuals with AAN may also experience muscle weakness, poor wound healing, and gastrointestinal distress. Additional potential symptoms include dry skin, dry and brittle nails, lanugo (fine hairs on the body to help keep the individual warm), and thinning of hair on the head. Dental problems are also common amongst individuals who engage in purging (American Psychiatric Association, 2022; Crone et al., 2023; Fitterman-Harris et al., 2024; Vo & Golden, 2022).
Ultimately, AAN can cause a significant amount of medical and psychological distress across different organs in the body. Individuals may develop cardiovascular problems (bradycardia and hypotension) or gastrointestinal problems (nausea, bloating, constipation, acid reflux, and involuntary vomiting). AAN can also affect the kidneys and may lead to hormonal changes, electrolyte imbalances, and anemia. Neurological issues may also develop, resulting in seizures, dizziness, syncope, sleep problems, and difficulty concentrating. In severe cases, AAN can result in death (Vo & Golden, 2022).
Steps Forward
Weight stigma plays a huge role in the lack of treatment and delayed treatment of individuals with AAN. As a society and especially in the medical field, it is important to challenge the myths about weight and eating disorders. Research indicates that individuals with AAN can be just as severe as those with AN (due to meeting the weight criteria) and that severity of EDs is influenced by the behaviors and symptoms experienced, rather than being reliant on weight status. Medical professionals need more training in weight inclusive care and in identifying risks for EDs, regardless of weight status (Harrop et al., 2021).
Opening the dialogue for individuals struggling with restrictive eating is important to help identify individuals with any restrictive ED, including AAN, and in arranging treatment for these individuals. Decreasing weight stigma and weight bias is a vital step in improving care for individuals with AAN, as well as an important step forward in changing the societal outlook on individuals in larger bodies.
Sources:
American Psychiatric Association. (2022). Diagnostic and statistical manual of mental disorders, 5th edition, text-revision (DSM-5-TR). American Psychiatric Association Publishing. https://doi.org/10.1176/appi.books.9780890425787
Brennan, C., Illingworth, S., Cini, E., & Bhakta, D. (2023). Medical instability in typical and atypical adolescent anorexia nervosa: A systematic review and meta-analysis. Journal of Eating Disorders, 11(1), 58. https://doi.org/10.1186/s40337-023-00779-y
Crone, C., Anzia, D. J., Fochtmann, L. J., & Dahl, D. (2023). The American Psychiatric Association practice guideline for the treatment of patients with eating disorders, fourth edition. American Psychiatric Association. https://psychiatryonline.org/doi/book/10.1176/appi.books.9780890424865
Daley, S. F., Ginsburg, B. M., & Sheer, A. J. (2025). Overcoming stigma and bias in obesity management. Treasure Island. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK578197/
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Sierra Dayton, M.ED., LPC
Aurora Counseling Center, LLC
About the Author: Sierra Dayton, M.ED., LPC is a Licensed Professional Counselor in private practice in Virginia Beach, Virginia. She owns and operates a private practice, Aurora Counseling Center LLC, where she specializes in treating individuals with eating disorders, borderline personality disorder, chronic illness, and neurodivergence. Sierra is passionate about advocating for individuals who do not fit stereotyped understandings of a diagnosis, such as individuals with eating disorders who are not underweight, men with eating disorders, and women with Autism who are high-masking. Sierra believes everyone is worthy of support and recovery, even if their struggles do not appear to meet society’s expectations. Sierra lives in Virginia Beach with her partner and their two cats. She enjoys listening to music, spending time with family and friends (especially her baby nephew), and continuously building her knowledge of mental health conditions and their treatments.