UCL in the News: Why gym may fix it

An important new study of UK schools indicates that pupils who do more physical education at school have significantly smaller waistlines.

This is a significant contribution to the debate about whether it's fitness or food we need to concentrate on if we're seriously going to address the nation's "obesity epidemic". …

The study, supported by Cancer Research UK and to be published in the International Journal of Obesity next month, will show that boys in secondary schools that provide three PE sessions a week have waists about 3cm (1.2in) slimmer than boys at schools that provide one or two sessions. …

The extent of this difference surprised the lead researcher, Professor Jane Wardle, the director of the Cancer Research UK Health Behaviour Unit at UCL, who says: "We were quite struck by the results." …

One of the key reasons that Professor Wardle's study has picked up different patterns from other studies into childhood obesity and exercise is that it looked at the children's waist size and not their body mass index (BMI). Most studies use changes in BMI (a figure based on the ratio between height and weight) as an indicator of how children are putting on weight over time. But Professor Wardle was concerned that BMI measurements weren't sensitive to the fact that exercise, while reducing fat, builds up muscles. Waist measurements are sensitive to this.

"Waist measurement is a much purer indication of fatness," she says. It's also important because studies have shown waist measurement to be a better indicator of the risk of coronary artery disease in adolescents than BMI. …

Simon Crompton, 'The Times'