Genetic research reshapes understanding of eating disorders, highlighting biological differences

A groundbreaking international study involving researchers from the University of Otago reveals that genetics play a crucial role in eating disorders, challenging traditional psychological explanations and paving the way for more targeted treatments.

A new international study involving researchers from the University of Otago suggests eating disorders are shaped by genetics as well as mental health, adding weight to a growing argument that they are not best understood as purely psychological illnesses. The work, led by teams at King’s College London and the University of North Carolina, was published in Nature Mental Health and drew on DNA from tens of thousands of people with binge eating or anorexia nervosa, including more than 500 participants in New Zealand.

The findings point to a biological divide between binge eating and anorexia nervosa. Researchers said genetic factors tied to higher body weight were linked to a greater chance of binge eating, while the same kind of genetic signal appeared to lower the likelihood of anorexia nervosa.

King’s College London said related analysis of more than 20,000 genomes also found that anorexia nervosa, bulimia nervosa and binge-eating disorder share genetic links with psychiatric conditions such as depression and schizophrenia. At the same time, the disorders differed in how they related to body weight regulation: anorexia nervosa was associated with a tendency towards lower body weight, while bulimia nervosa and binge-eating disorder were tied to a higher genetic risk of obesity and a higher BMI.

The researchers said that meant the genetic contribution to eating disorders could not be reduced to genes affecting body size alone. Jenny Jordan, an associate professor at the University of Otago, said the results marked an important change in how these conditions may be understood and treated. “These results not only help us understand both shared and distinct causes of these eating-related traits but may also help us develop more precise treatments targeting the specific biology of each condition,” she said.