And school PE reinforces a sense
of inadequacy and abnormality in overweight pupils, even when classes are deliberately designed to encourage healthy living.
Following media and government focus on a perceived obesity epidemic among pupils, PE is often promoted as a means to safeguard children's health and encourage future participation in sports.
But Suzanne Groves of Chichester University argues that many overweight people are dissuaded from taking part in sports throughout their life as a result of their experiences of school PE.
She claims that obese pupils often feel they do not have the right to participate in PE lessons, even when they enjoy physical activity.
Young children derive a sense of their own ability from their teacher. So, if the teacher does not motivate or encourage pupils, those pupils are unlikely to engage fully in PE.
Dr Groves said: "The demands being placed on the profession are sufficiently diverse as to result in teachers being unable to address the very specific needs of these children within the PE lesson."
But resulting negative self-perception often becomes entrenched as the pupils move through education. Peer responses during PE also have an impact. Bullying about weight is often exacerbated by a subject where the focus is on the body and its movement. This reinforces any existing sense of difference.
Dr Groves said: "Not only do these children appear different to others, but the way in which they move is also affected by the problems they have."
Parents' perceptions of PE also have a significant impact. If parents did not enjoy school sport, their children are likely to have a negative attitude from the outset.
"Exercising is simply not something that they do," she said. "Many of these children do not have a positive relationship with the concept of physical activity and dissociate themselves from it."
Such attitudes extend to extra-curricular PE activities. Many overweight children felt they did not have the right to take part in these, even when they wanted to.
One parent told Dr Groves: "Nobody wants to know because he's not good enough to be in a team."
Dr Groves concludes that schools should provide classes which cater specifically to the needs of overweight pupils. This reduces any physical self-consciousness instead of being perceived as abnormal, these pupils become the norm.
This, she believes, would enable overweight pupils to experience sport without social anxiety: "A specifically designed programme can redefine children's sense of their physical self, which may ultimately lead to greater participation in physical education."
* Physical education and obesity issues, by Suzanne Groves S.Groves@chi.ac.uk