New study shows children are less fat – but less fit. The ‘obesity crisis’ may be a fitness crisis

    19 June 2015

    A long-term study by the University of Essex has found that, although the average BMI (body mass index) of children has fallen, their fitness levels are down, too. In short, they are less fat but also less fit.

    The researchers said that one of the least fit children they tested in 1998 would be one of the five fittest in a class of the same age today.

    In 2009 they found that child fitness had declined by eight percent over the previous decade. This time the decline is even greater – but the children were on average thinner than those monitored previously.

    As Christopher Snowden points out, BMI is calculated by dividing a person’s height by their weight. The Essex study – which shows no correlation between lower BMI and increased fitness – lends support to the argument that it is of limited usefulness.

    The researchers tested 300 pupils aged between 10 and 11. They expected that children with a lower BMI would perform better than the heavier children they measured six years ago, but that wasn’t the case.

    ‘Simply put, if you weigh less it is easier to run and turn so you should do better on our test,’ said Dr Gavin Sandercock, the project’s lead researcher.

    ‘But despite finding a lower average BMI in the children measured in 2014 than in 2008 we found the children still couldn’t run as fast, showing they had even lower cardiorespiratory fitness.’

    ‘Our findings show there is no obesity crisis in the schools we went to, as less than five per cent of pupils were obese and the average BMI is now below 1998 values. This would be good news if BMI was all we had measured, but our fitness tests tell a different story.’

    The findings suggest that fitness has been declining at 0.95 per cent per year – over twice that of the international average. And male fitness levels are falling at a particularly alarming rate.

    The Essex scientists are calling for a rethink on how children’s health is monitored. They would like to introduce child fitness testing in schools, which would measure a child’s ‘physical literacy’ at each key stage, as they do currently for academic subjects.

    In the meantime, the study suggests that Britain’s much-publicised ‘obesity crisis’ may be less significant than a fitness crisis in our schools.