GOVERNMENT guidelines for children's physical activity, to

stave off obesity and obesity-related diseases need rethinking,

according to a study.

Ten-year-old guidelines, which recommend children need an

hour's moderate physical activity a day, are dated and need to

be revised, according to researchers at Peninsula Medical

School in Plymouth.

The Earlybird study, examining a group of 307 children, from

the ages of five to 16, has already provided evidence exercise

plays little role in a child's weight (or body mass index).

Professor Terry Wilkin, director of the study, said there

were two important findings from the first three years of the

study.

He said: “First, the weight measure that people use, the

body mass index, doesn't pick up any difference for those

children who do and don't meet physical activity guidelines.

It's a very rough index and a very blunt tool.

“Second, if you look at the blood samples of the children,

you can see those who do more exercise benefit metabolically

than those who don't.”

The results of the study, published today in Archives of

Disease in Childhood, show less than half of boys and only one

in eight girls manage the recommended weekly amounts.

The researchers base their findings on the long term

monitoring of 113 boys and 99 girls from 54 different schools,

all of whom were five years old when the study started in

2001.

The children's weekly physical activity levels were measured

using a tiny device worn around the waist and designed for the

purpose.

Changes in weight and predictive health indicators, such as

insulin resistance, blood fat and cholesterol levels, and blood

pressure were measured annually between the ages of five and

eight.

Taken together, these health indicators reflect the risk of

developing cardiovascular disease and diabetes.

Both the UK and US guidelines recommend children are

moderately physically active for at least an hour every day, in

a bid to stave off obesity and its attendant health risks. And

they measure body mass index (weight) to monitor impact

The results showed there was a wide range of physical

activity among children, some spending as little as ten minutes

a day at the recommended intensity while others were spending

more than 90 minutes a day. Around 42 per cent of boys, but

only 11 per cent of girls, met the 60-minute guideline.

The authors suggest the measure used to gauge impact may

simply be too crude, and applying the same guideline to both

sexes may not be appropriate.

Prof Wilkin added: “Children who do more exercise benefit,

but we still have no idea how to encourage those who do not

meet the deadline to do more.”