Academics who interviewed 36 teenagers from very deprived backgrounds attending three schools found that, contrary to popular belief, acceptance of body size and shape was common among overweight and obese teenagers who made up half the research group.
The findings may have implications for the Scottish Executive's strategy of improving health and well-being in Scottish schools and of improving young people's eating habits and physical exercise .
Wendy Wills, now at the University of Hertfordshire, and former colleagues from the research unit in health, behaviour and change at Edinburgh University, said: "Our findings draw attention to the ways in which the current medicalised view that 'thin is good' while 'fat is bad' overlooks the perceptions of the population who are thought to be in most need of protection.
"We found that not all overweightobese teenagers are bullied; that bodies defined by their BMI (body mass index) as being overweightobese are not always perceived as fat or unaccept-able; and that not all teenagers (particularly girls) are striving for thinness.
"We hope that this study, and any further work which arises from it, will inform and challenge current public health debates about teenage obesity."
The research, to be published in the Journal of Social Science and Medicine, claims that definitions of "normal" weight, overweight and obesity do not take account of the complexity of feelings that teenagers have about their bodies.
The teenagers were questioned on the perceived causes of fatness and body size; the professed consequences of being fat; their experiences of attempting to lose weight; and how their friends and family viewed fatness and dieting.
Contrary to popular belief, acceptance of body size and shape was common among overweight and obese teenagers. Many of the teenagers questioned were dismissive of attempts by others to lose weight, with most reporting that size is not important.
The study states: "People from working-class backgrounds, like the participants in this study, have been reported as being more satisfied with their overweight bodies than their middle-class peers. It is impossible to draw firm conclusions about the importance of social class without comparison with young people from higher socio-economic groups.
"Whereas middle-class teenagers may value thinness and therefore hold negative attitudes to overweightobesity, young teenagers from working-class backgrounds may value bodies that are simply free from illness and capable of performing everyday activities."
But some overweight and obese boys in the study said that they valued being able to run about with their friends and did not like it when their body size slowed them down.