What is atypical anorexia?

Atypical anorexia occurs when all criteria are met for anorexia nervosa such as restricting food and fluid, purging, and fear of gaining weight (read more about the symptoms of anorexia here). The defining feature of atypical anorexia is that the person affected is not underweight according to their body mass index (BMI), and they may even be in a higher weight body.

Despite restricting and/or purging, people with atypical anorexia do not lose a significant amount of weight. However, they still experience all of the serious health risks as people with anorexia.

Atypical anorexia diagnostic criteria

Atypical anorexia is not recognized as a separate diagnosis in the Diagnostic and Statistical Manual 5 (DSM-5), but falls under the category of “Other Specified Feeding or Eating Disorder” (OSFED). Atypical anorexia is diagnosed when a person meets the DSM-5 symptoms of anorexia except the low weight. It is important to note that a person with atypical anorexia can experience weight loss (and thus weight gain upon treatment), but the weight loss never falls below what is considered unhealthy on the BMI scale (this cut off is typically a BMI of 18.5)

Who is affected by atypical anorexia?

Just like anorexia, atypical anorexia does not discriminate and can affect both sexes, all gender identities, age groups, demographics and socioeconomic statuses. Because of the recent recognition of atypical anorexia, there are very few studies that assess who and how many people are affected by atypical anorexia.

One review of the research literature spanning 2007 to 2020, found that atypical anorexia occurs more frequently than anorexia with a prevalence of up to 13% (Harrop et al., 2021). In the same review, the authors found that the majority of people with atypical anorexia were adolescent females. Thus, despite its name, research suggests that atypical anorexia is not that atypical among the general population.

However, similar to anorexia, there are several reasons why this prevalence rate may not be reliable, including underdiagnosis of anorexia in males, older adults, people of color and LGBTQIA+ groups. Anorexia is underdiagnosed among all ages, sexes and genders but some groups are more affected. This underreporting is in large part attributed to the incorrect belief that anorexia is a disease that belongs to “young, white, wealthy, cis-females”.

Some of the groups that are affected by anorexia, but often go undiagnosed are:

Males: Healthcare providers often overlook symptoms of anorexia in males and studies often do not include male participants.
Older adults: Although anorexia typically emerges during adolescence, recent research shows that anorexia is also prevalent among older people. While this prevalence can often be attributed to chronic, untreated anorexia, new research also finds that anorexia can emerge in adulthood. However, these patients often go undiagnosed simply because of their age.
Minority groups: People of color and LGBTQIA+ groups are also underdiagnosed, despite being at higher risk for eating disorders due to their higher load of trauma exposure.

In addition, atypical anorexia is often overlooked by researchers and healthcare providers because:

It is a newer diagnosis and they lack awareness.
They carry a weight stigma that leads them to think that only underweight people can have anorexia.

Factors that increase the risk of developing atypical anorexia.

Genetics: Individuals with a family history of eating disorders may have a higher risk of developing atypical anorexia. Genetic factors can play a role in predisposing individuals to eating disorders.
Sociocultural pressures: Societal and cultural factors, such as the emphasis on thinness and dieting, can influence body image and contribute to disordered eating behaviors, including atypical anorexia. Pressure to conform to certain beauty standards can be a significant risk factor.
Psychological factors: Psychological factors like perfectionism, low self-esteem, high levels of anxiety, and a preoccupation with body image can contribute to the development of atypical anorexia. These traits can lead to restrictive eating patterns and an intense focus on weight and shape.
Dieting and Weight-Related Behaviors: Engaging in extreme dieting, weight loss practices, or excessive exercise in an attempt to control weight can increase the risk of developing atypical anorexia. These behaviors may lead to significant weight loss and restrictive eating habits.
Medical conditions or medication: Certain medical conditions, such as gastrointestinal disorders or thyroid dysfunction, can contribute to changes in appetite or metabolism, potentially leading to weight loss and restrictive eating patterns. Medications that affect appetite or weight can also be a factor.

It's important to note that atypical anorexia is a complex condition, and individual risk factors can vary. Additionally, the development of eating disorders like atypical anorexia often involves the interplay of multiple factors.

No matter who you are, the sooner you get help for atypical anorexia, the better.

Serious atypical anorexia symptoms & health risks.

The health risks associated with atypical anorexia are similar to and equally as serious as those associated with anorexia (Vo & Golden, 2022, Sawyer et al., 2016).

These include:

Cardiac complications such as a low or abnormal heart rate
Low body temperature
Low blood pressure
Severe dehydration
Kidney damage
Muscle loss
Hair loss
Osteoporosis (reduction of bone density)
Dental decay
Gastroesophageal reflux disease
For women, amenorrhea (suppression of menstrual cycle) and fertility issues may occur

Atypical anorexia treatment outcomes.

There is minimal research on the best treatment strategies and outcomes for people with atypical anorexia (Walsh et al., 2023). Currently, most people with atypical anorexia receive treatment that is similar to anorexia. A concerning statistic is that people with atypical anorexia are less likely to receive treatment compared to people with anorexia (Harrop et al., 2021).

We know that for people with anorexia, treatment outcomes are better when started early after disease onset. The delayed and lack of treatment intervention for people with atypical anorexia may explain why some studies record worse eating disorder symptoms in this patient group compared to people with anorexia (Harrop et al., 2021, Sawyer et al., 2016 ).

Over the last five years, Monte Nido & Affiliates have tracked the treatment outcomes of our clients with OSFED after six months of residential treatment. While the OSFED diagnostic category includes several diagnoses, the majority of our clients with OSFED have atypical anorexia. If you have atypical anorexia you can expect to experience the following improvements after six months of residential treatment at a Monte Nido program:

93% of clients reported reduced eating disorder symptoms in the Eating Disorder Examination Questionnaire
81% of clients reported reduced eating disorder symptoms in the Eating Disorder Inventory self-report
82% of clients reported improvement in their quality of life
85% of clients reported improvements in depression
74% of clients reported reductions in anxiety symptoms
77% of clients who had PTSD upon admission reported reduced trauma symptoms

You are not alone. We’re here to help.

One of the best ways to improve treatment outcomes is to start treatment early. If you are concerned that you, or a loved one, may have an eating disorder, we are here to help.

Please reach out or email Admissions@MonteNidoAffiliates.com to connect with a member of our Admissions Team. Begin your journey to recovery today.

Reach Out Today

Residential and Day Treatment Programs for Adults and Adolescents of All Genders (National)

Visit Monte Nido

Inpatient, Residential and Day Treatment Programs for Adults and Adolescents of All Genders (Northeast)

Visit Walden

Inpatient, Residential and Day Treatment Programs for Adults and Adolescents of All Genders (Arizona)

Visit Rosewood

Residential Treatment Programs for Adolescents of All Genders (National)

Visit Clementine

Accredited by The Joint Commission

CITATIONS:

Harrop EN, Mensinger JL, Moore M, Lindhorst T. Restrictive eating disorders in higher weight persons: A systematic review of atypical anorexia nervosa prevalence and consecutive admission literature. Int J Eat Disord. 2021 Aug;54(8):1328-1357. doi: 10.1002/eat.23519. Epub 2021 Apr 17. PMID: 33864277; PMCID: PMC9035356.

Vo M, Golden N. Medical complications and management of atypical anorexia nervosa. J Eat Disord. 2022 Dec 16;10(1):196. doi: 10.1186/s40337-022-00720-9. PMID: 36522787; PMCID: PMC9756584.

Sawyer SM, Whitelaw M, Le Grange D, Yeo M, Hughes EK. Physical and Psychological Morbidity in Adolescents With Atypical Anorexia Nervosa. Pediatrics. 2016 Apr;137(4):e20154080. doi: 10.1542/peds.2015-4080. Epub 2016 Mar 29. PMID: 27025958.

Walsh BT, Hagan KE, Lockwood C. A systematic review comparing atypical anorexia nervosa and anorexia nervosa. Int J Eat Disord. 2023 Apr;56(4):798-820. doi: 10.1002/eat.23856. Epub 2022 Dec 12. PMID: 36508318.