Lessons in healthy eating have led pupils to equate thinness with academic success, encouraging eating disorders such as anorexia, according to new research.
An increased focus on health, fitness and obesity means teenage girls now see their bodies in the same way as school work: something to be assessed or compared with other pupils' achievements, say academics at Loughborough University.
In a study spanning five years, they interviewed 40 girls aged 11 to 18, who were anorexic or bulimic.
Most were perfectionists and high-achievers, regarding even A-grades as unexceptional.
Teenager Carrie said: "Even if you work very hard and get an A, and then someone else gets an A* ... they have taken the achievement away from you."
But the girls also applied this attitude to school lessons in healthy eating. "Young people's bodies are ... perceived in similar ways to academic excellence, as something to be managed, regulated, measured and compared," the researchers said.
This was particularly true when pupils were asked to weigh themselves as part of a lesson. Weighing offered a tangible result, which could then be improved upon.
"Weighing ... is a mechanism for achieving an assessed outcome," the academics said. "These young women continue to strive towards excellence."
Similarly, Lydia described how her teacher praised a very thin girl for being "the right weight". She said: "That really upset me, because I just thought, 'I have to get my weight down quick'."
Vicky agreed. "Everything has to be right, cos I'm, like, a control freak," she said. "Everything has to be perfect."
As schools are now inspected on healthy eating practices, teachers also viewed their pupils' bodies in terms of targets and standards.
And, just as pupils who fall behind academically are offered remedial classes, so pupils who failed to achieve an ideal weight or body shape were offered "treatment, repair and restoration", the researchers said.
But just as academic success is relative to the success of others, so the girls' attempts to achieve thinness were also judged in relation to their classmates.
Teenager Ruth said: "If I see someone having something healthier than me, I immediately feel guilty."
Lauren agreed: "I was just the anorexic. That was who I was," she said. "And when this other girl at the school became anorexic, I felt that I had been pushed out of my place."
For many of the girls, it was vital to make their "achievements", whether academic or physical, appear effortless. But classroom emphasis on assessment and achievement inspired constant fear of failure.
"Effortless achievements may come at a cost, and may be accompanied by guilt and feelings of inadequacy," the researchers said. "Performativity creates a number of social and emotional anxieties, not only for those who may 'fail' in such a culture, but for those who are seen to succeed."
But Susan Ringwood, chief executive of eating disorder charity beat, is unconvinced. "We know pressures to perform and achieve can increase the risk of eating disorders among young people who are vulnerable to them.
"And if you raise people's concern about weight and shape, there are some people who will be more at risk. But I'm not persuaded that there's a causal relationship."
'OOH GREAT, I LOOK ILL'
- I was starved when I took my GCSEs. I was really dizzy ... but it was important that I sat them. Karen
- You want people to notice you as well. So you want to be noticed as the stunning, skinny people. Lydia
- I always used to look at my friends and think that I wanted to be as good, or as pretty, or as clever as them. Not eating was a way that I could achieve that. Hayley
- I was just the anorexic; that was who I was. And when this other girl became anorexic, I felt pushed out and I was furious. Lauren
- My teachers used to go, 'oh, you look pale'. And I used to think, 'ooh, great. I look ill. I must be doing well.' It means I'm doing OK with my anorexia. Ellie.