Teenage girls attending schools where more pupils are female and more parents have gone through university education have a higher risk of developing an eating disorder, scientists claim. While researchers are hesitant to speculate the reasons for this - and say far more research is needed before conclusions are made - they note a culture of perfectionalism and peer pressure could be to blame.
The study, conducted by a joint Sweden-UK team and published in the International Journal of Epidemiology, aimed to pinpoint different risk factors associated with disorders such as bulimia, anorexia or binge eating.
"Eating disorders have an enormous effect on the lives of young people who suffer from them – it is important to understand the risk factors so that we can address them," said lead author Helen Bould, from the University of Oxford.
In the UK, about 1.6 million of people could be affected by these disorders, according to the charity Anorexia & Bulimia Care, so understanding what drives these enormous numbers is a priority.
10% more risk
The study is based on a very large cohort, making its results more credible. The scientists collected data from a big population register in Sweden, analysing the information of more than 55,000 girls aged 15 to 18.
After adjusting for individual confounding factors, such as family history of eating disorders, mental health or family income, they investigated whether specific school characteristics increased the risks of being diagnosed with an eating disorder.
They found that, across all the girls included in the study, the overall chance of having an eating disorder was 2.4%. However, this risk was higher for girls attending schools with higher numbers of female students, and greater proportions of higher-educated parents, in comparison with girls in schools with lower proportions of female students and fewer university-educated parents.
It rose by 10% for each 10% rise in the proportion of girls attending a school, and by just over 10% for each 10% rise in the proportion of parents with a higher education.
'Aspirational school culture' link?
Despite clearly identifying a link between school characteristics and eating disorders, the study stops short of explaining the trend. Different hypothesis are raised, and could be explored in future studies.
'Unfortunately, this study can't tell us what it is about schools that affects the rates of eating disorders", Bould explains. "It might be an unintentional effect of the aspirational culture of some schools that makes eating disorders more likely or it might be that eating disorders are 'contagious' and can spread within a school. On the other hand, it could be that some schools are better than others at identifying eating disorders in their students and ensuring they get diagnosed and treated."
The study adds: "Schools with more students from more educated families may have higher aspirations and exert greater demands on their students. This may encourage perfectionism, which is strongly associated with [eating disorders] ... Students may also 'learn' eating disordered behaviours from witnessing others. Research suggests that body image concern, extreme weight loss behaviours and bingeing are influenced by friendship group."