Helen Bould

The influence of school on whether girls develop eating disorders

Abstract Background: Clinical anecdote suggests that rates of eating disorders (ED) vary between schools. Given their high prevalence and mortality, understanding risk factors is important. We hypothesised that rates of ED would vary between schools, and that school proportion of female students and proportion of parents with post-high school education would be associated with ED, after accounting for individual characteristics. Method: Multilevel analysis of register-based, record-linkage data on 55 059 females born in Stockholm County, Sweden, from 1983, finishing high school in 2002-10. Outcome was clinical diagnosis of an ED, or attendance at a specialist ED clinic, aged 16-20 years. Results: The 5-year cumulative incidence of ED diagnosis aged 16-20 years was 2.4%. Accounting for individual risk factors, with each 10% increase in the proportion of girls at a school, the odds ratio for ED was 1.07 (1.01 to 1.13), P = 0.018. With each 10% increase in the proportion of children with at least one parent with post-high school education, the odds ratio for ED was 1.14 (1.09 to 1.19), P < 0.0001. Predicted probability of an average girl developing an ED was 1.3% at a school with 25% girls where 25% of parents have post-high school education, and 3.3% at a school with 75% girls where 75% of parents have post-high school education. Conclusions: Rates of ED vary between schools; this is not explained by individual characteristics. Girls at schools with high proportions of female students, and students with highly educated parents, have higher odds of ED regardless of individual risk factors.

Do eating disorders in parents predict eating disorders in children? Evidence from a Swedish cohort

We investigated whether parental eating disorders (ED) predict ED in children, using a large multigeneration register‐based sample.

The influence of school in the development of eating disorders: a record-linkage study

BACKGROUND Clinical impression is that rates of eating disorders vary between schools; we are not aware of any previous research on this topic. We aimed to investigate whether rates of eating disorders in 16-20-year-old girls vary between upper secondary schools, and to test the hypothesis that school characteristics are associated with rates of eating disorders, even after accounting for characteristics of individual students. METHODS This multilevel longitudinal study made use of record-linkage data from Stockholm County, Sweden. Participants were 55 824 Swedish-born girls completing secondary education in 2001-10 at 409 schools. Outcome was any diagnosed eating disorder at 16-20 years, as defined by an ICD (9 or 10) or DSM-IV code, or inferred from an appointment at a specialist eating disorder clinic. Multilevel modelling was used to separate individual and school level effects. The Stockholm Regional Ethical Review Board approved the study. FINDINGS A 4·4% variation in incidence of eating disorders between schools was seen; after taking individual risk factors into account variation between schools was 2·9% (95% CI 1·5-5·0). Schools with a higher proportions of girls than boys had an increased incidence of eating disorders: for each 10% increase in the proportion of girls at a school, the odds ratio for eating disorders was 1·07 (95% CI 1·01-1·13, p=0·017). For each 10% increase in the proportion of parents with post-secondary education, the odds ratio for eating disorders was 1·14 (1·09-1·19, p<0·0001). INTERPRETATION Our findings show that the contextual aspects of a school environment are associated with increased incidence of eating disorders. Incidence rates of eating disorders are higher in schools characterised by a high proportion of female students and of students with highly educated parents. To our knowledge, this is the first study to investigate whether rates of eating disorders vary between schools; however, use of registry data means that individuals who did not seek treatment would not have been studied. FUNDING HB was supported by a Wellcome Trust Institutional Strategic Support Fund (via the Elizabeth Blackwell Institute).

Effects of visual adaptation on perception of and satisfaction with own body size: two randomised studies

Abstract Background Body dissatisfaction is prevalent among women and predicts eating disorders and obesity. Visual adaptation to pictures of underweight or overweight bodies changes body size perceived as normal in others. We aimed to test the hypothesis that exposure to images of underweight or overweight bodies would change perception of and satisfaction with own body size. Methods We recruited female students and staff aged 18–25 years from the University of Bristol via posters and emails. In study 1, participants had normal body-mass index (BMI) (19–25 kg/m 2 ). In study 2, they had normal BMI and also high body dissatisfaction (defined as a score of >35 on the Body Dissatisfaction subscale of the Eating Disorder Inventory). Both studies had 80% power to detect an effect size of 0·36 (p=0·05). A computer-generated random sequence randomised participants into three groups, according to which category of images they would see. Participants and experimenters were masked to randomisation; and participants were unaware of the study purpose. Participants completed a 15 min adaptation task consisting of their looking at photographs of women of the same age group altered by the authors to appear slightly underweight, normal weight (control group), or slightly overweight Participants then looked at themselves in a mirror. Visual analogue scale (VAS) scores were taken before adaptation and again after adaptation and looking in the mirror. The analysis compared post-adaptation scores adjusted for pre-adaptation scores. We measured perceived size (primary outcome) and satisfaction with size (secondary outcome) and analysed data by intention to treat using linear regression, adjusting for baseline. Ethics approval for both studies was given by the Faculty of Science Research Ethics Committee, University of Bristol. Participants gave consent after being informed about the task they would complete. Findings We recruited 90 women between Nov 11, 2012, and Dec 16, 2013 in study 1; and 93 women (July 29, 2014, to Aug 8, 2015) in study 2. After adaptation, for every VAS point increase in group (underweight 0, normal 1, overweight 2), perceived own size post adaptation decreased by 2·2% (95% CI −4·1 to −0·3, p=0·02) in study 1, and 2·8% (–5·1 to −0·4, p=0·02) in study 2. Satisfaction with size increased by 1·5% (95% CI −0·9 to 3·9, p=0·21) in study 1 and 5·7% (2·3 to 9·0, p=0·001) in study 2. Participants shown underweight images subsequently perceived themselves as larger and were less satisfied. Interpretation These findings suggest that, in young women, exposure to underweight images (frequently depicted in the media) changes perception of own body size and increases body dissatisfaction. This automatic mechanism could be targeted at a public health level by advocating replacement of underweight images with normal weight images. Such an intervention could reduce body dissatisfaction in normal weight women and possibly rates of eating disorders and obesity. Funding Study 1 was unfunded. For study 2, HB was funded by an Elizabeth Blackwell Clinical Primer (Wellcome Trust Strategic Support Fund) from April to September, 2014, and subsequently as a Wellcome Trust Doctoral Training Fellow (October, 2014, to the present).