The Role of Metabolism & Genetics in Anorexia Nervosa

Young Woman Standing Outside Her Eating Disorder Recovery Center

For years, doctors and therapists blamed the development of anorexia nervosa on environmental factors like overbearing parents or controlling mothers. Thanks to numerous studies on the genetics behind eating disorders, it is now evident that parents do not cause their children to develop eating disorders (at least not in the way everyone thought). Instead, eating disorders like anorexia nervosa have a strong genetic component. Twin studies reveal that up to 60 percent of a person’s risk of developing anorexia nervosa can be attributed to their inherited genetics, metabolism, and other biological factors [1].

Since the discovery that genetic factors play such a critical role in the development of anorexia nervosa, doctors and researchers have generally believed that anorexia nervosa’s genetic origins are purely psychiatric in nature. But a new study suggests metabolic genetics also play a critical role in the development of AN.

Girl with genetics that predispose her to anorexiaLed by a group of researchers from the University of North Carolina at Chapel Hill and King’s College London, the study examined a dataset that included 55,525 controls and 16,992 anorexia nervosa cases spread across 17 different countries. Over 100 academics from around the world participated in the genome-wide association study.

While they pinpointed eight different genetic variants linked to anorexia nervosa (AN), the most surprising discovery was that not all of these genetic variants are psychiatric in nature. Instead, they found that “the genetic basis of anorexia nervosa overlaps with metabolic (including glycemic), lipid (fats), and anthropometric (body measurement) traits […]” [2].

And perhaps even more surprising is the researchers’ conclusion that “the metabolic factors may play nearly or just as strong a role as purely psychiatric effects” [3].

In other words, while the study confirmed that individuals with anorexia nervosa contain certain genetic variants that make them more vulnerable to developing an eating disorder, it found that not all of these genetic factors are psychiatric. Instead, metabolic abnormalities (previously regarded as side effects of AN) may actually be one of the key contributors to the development of anorexia nervosa.

“Metabolic abnormalities seen in patients with anorexia nervosa are most often attributed to starvation, but our study shows metabolic differences may also contribute to the development of the disorder,” writes Dr. Gerome Breen, one of the leaders of the study [4].

So rather than thinking of anorexia nervosa as merely a mental illness or psychiatric disorder, the researchers contend that AN is a ‘metabo-psychiatric disorder.’

Metabolism & Genetics Discovery Opens Door to New Treatment Options

This study confirms that anorexia nervosa is an illness with both psychiatric and physical features and “suggest[s] that integrating metabolic information may help clinicians to develop better ways to treat eating disorders,” says Professor Janet Treasure, from the Institute of Psychiatry, Psychology & Neuroscience, King’s College London [5].

It may also provide insight as to why some AN patients “drop back to dangerously low weights, even after hospital-based refeeding,” shares Professor Cynthia Bulik, from the University of North Carolina [6].

The study concludes with a statement by Andrew Radford, Chief Executive of the UK’s eating disorder charity, Beat: “This is ground-breaking research that significantly increases our understanding of the genetic origins of this serious illness. We strongly encourage researchers to examine the results of this study and consider how it can contribute to the development of new treatments so we can end the pain and suffering of eating disorders” [7].


[1] Trace, S. E., Baker, J. H., Peñas-Lledó, E., & Bulik, C. M. (2013). The genetics of eating disorders. Annual review of clinical psychology, 9, 589–620.

[2] ScienceDaily. (2019, July 15). Genetic study reveals metabolic origins of anorexia. ScienceDaily.

[3] ibid.

[4] ibid.

[5] ibid.

[6] ibid.

[7] ibid.

About the Author:

Sarah Musick PhotoSarah Musick is a freelance writer who specializes in eating disorder awareness and education. After battling with a 4-years long eating disorder, she made it her mission to help others find hope and healing in recovery.

Her work has been featured on numerous eating disorder blogs and websites. When she’s not writing, Sarah is off traveling the world with her husband.

The opinions and views of our guest contributors are shared to provide a broad perspective on eating disorders. These are not necessarily the views of Eating Disorder Hope, but an effort to offer a discussion of various issues by different concerned individuals.

We at Eating Disorder Hope understand that eating disorders result from a combination of environmental and genetic factors. If you or a loved one are suffering from an eating disorder, please know that there is hope for you, and seek immediate professional help.

Published November 26, 2020, on
Reviewed & Approved on November 26, 2020, by Jacquelyn Ekern MS, LPC