Genes provide new clues about eating disorders
Binge eating disorder and anorexia nervosa share some genetic features, but they also differ in important ways. This is shown in a new study published in Nature Mental Health, in which researchers, including scientists from Karolinska Institutet, analyzed genetic data from tens of thousands of individuals. The findings contribute to a better understanding of the biological basis of different forms of eating disorders.
Eating disorders have long been viewed primarily as psychological conditions. In the new study, researchers examined how genetic factors are associated with binge eating behavior and anorexia nervosa. The analysis included nearly 40,000 individuals with binge eating behavior and around 25,000 individuals with anorexia nervosa. These groups were compared with more than 1.2 million individuals without eating disorders.
The researchers identified six genetic regions associated with binge eating behavior and eight regions associated with anorexia nervosa in individuals of European ancestry. Two of the genetic regions linked to anorexia nervosa had not previously been identified.
The study also shows that the genetic associations with binge eating and anorexia nervosa differ from the genetic factors that influence body mass index (BMI), even though body weight is an important factor in both conditions. This suggests that eating disorders cannot be understood solely in terms of weight or metabolism.
“Our findings show that eating disorders are not just about body weight. Many of the genetic variants associated with these conditions differ from the variants that influence how much a person weighs. This provides a more nuanced picture of the biological basis of eating disorders,” says Lu Yi, Principal Researcher at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet.
The researchers also found that both binge eating and anorexia nervosa shared genetic links with other psychiatric conditions, such as depression and anxiety. At the same time, clear differences were observed between the two forms of eating disorders. Anorexia nervosa showed stronger genetic links to obsessive-compulsive disorder (OCD), whereas binge eating behavior showed stronger links to attention-deficit/hyperactivity disorder (ADHD). In addition, genetic factors associated with higher body weight were linked to an increased risk of binge eating, but to a decreased risk of anorexia nervosa.
One of the genetic signals associated with binge eating behavior was identified near the FTO gene, which is already known to be associated with higher body weight. The findings suggest that binge eating may partly explain the relationship between this gene and BMI.
“The study demonstrates that different eating disorders are partly driven by distinct biological mechanisms. In the long term, this knowledge may contribute to more targeted treatment strategies that take into account the specific characteristics of each condition,” comments Lisa Dinkler, Assistant Professor at the Department of Medical Epidemiology and Biostatistics. Together with Lu Yi, Lisa Dinkler is one of the principal investigators of the ongoing EDGI2 study in Sweden that is extending this work.
The EDGI2 researchers now plan to expand their work to include other eating disorders, such as atypical anorexia nervosa and ARFID (avoidant/restrictive food intake disorder), as well as additional population groups, in order to increase global knowledge of the genetic factors underlying eating disorders.
The study was conducted within the Eating Disorders Working Group of the Psychiatric Genomics Consortium and involved researchers from a large number of universities and research institutions worldwide, including Karolinska Institutet. The research was funded in part by the U.S. National Institutes of Health (NIH) and the National Institute for Health and Care Research (NIHR) Biomedical Research Centre at Maudsley. No information regarding potential conflicts of interest was included in the material provided.
Publication
Termorshuizen, J.D., Davies, H.L., Lee, SH. et al. eating disorder phenotypes. Nat. Mental Health, online 20 Aug 2026, doi: 10.1038/s44220-026-00698-2.