Media release

From: Flinders University

Weight-related peer teasing is a strong predictor of disordered eating behaviours in adolescents, particularly those at higher genetic risk, new research shows.

Focusing on teenagers, the Flinders University study found that specific environmental factors including peer pressure and conflict with parents can increase the risk of sometimes dangerous disordered eating behaviours – particularly among those with higher genetic risk.

“This study demonstrates that genetic risk for anorexia nervosa exerts a stronger influence on disordered eating behaviours in adolescent girls when combined with adverse parental and peer relationships. These social factors – including parental expectations, criticism, and care, as well as weight-related peer teasing – are pivotal in shaping vulnerability to disordered eating,” says Professor Sarah Cohen-Woods, senior author of the article in the Journal of Child Psychology and Psychiatry.

“It appears that modifiable factors, such as positive peer relationships, and parental behaviour and relationships with their children, may be leveraged to reduce the impact of increased genetic risk for disordered eating behaviours.”

Preventative efforts should target environmental influences such as weight-related peer teasing, and parental interactions and relationships with their children, particularly in those that are genetically at risk.

“For example, high parental expectations or criticism may increase genetic risk for self-induced vomiting and avoidance of eating.

“Weight-related peer teasing was found to increase the influence of genetic factors on disordered eating behaviours, such as objective bulimic episodes.”

The study of 383 Australian teenage twin girls aged between 14 and 19 collected responses to capturing their self-reported experiences of parental expectations, parental criticism, parental care, weight-related peer teasing and parental conflict.

Professor Cohen-Woods, from the Flinders University Institute for Mental Health and Wellbeing, says research into the complex interplay between genetic predisposition and environmental factors can in the long term inform and improve clinical and non-clinical solutions to eating disorders.

“The research into anorexia nervosa polygenic risk scores in context with other known environmental risk factors highlights that a person’s genetic risk is not an isolated factor but can be significantly influenced by their social and family environment.”

The research, led by the Blackbird Initiative at the Flinders Institute for Mental Health and Wellbeing,

bridges a gap between psychosocial research and molecular genetics, demonstrating a gene-environment interaction using polygenic risk scores and existing parental and peer teasing data.

Researchers, however, say future research is needed with larger cohorts and a broader range of environmental measures to further investigate these complex relationships to guide support and prevention efforts for young people, benefiting everyday families and communities in the future.

The article, ‘Predicting adolescent disordered eating and behaviours: exploring environmental moderators of polygenic risk’ (2025) by Madeleine Curtis, Lucia Colodro-Conde, Sarah E Medland, Scott Gordon, Nicholas G Martin, Tracey D Wade and Sarah Cohen-Woods has been published in the Journal of Child Psychology and Psychiatry First published: 09 July 2025 https://doi.org/10.1111/jcpp.70012

Acknowledgements: This work was supported by Grants 324715 and 480420 from the National Health and Medical Research Council (NHMRC) to TDW, and NHMRC Ideas Grant 2030216 to SCW. Administrative support for data collection was received from the Australian Twin Registry, which is supported by an Enabling Grant (ID 310667) from the NHMRC administered by the University of Melbourne. The Breakthrough Mental Health Foundation supported the genotyping at Erasmus Medical Centre.

The authors have declared that they have no competing or potential conflicts of interest