No link between watching too much TV and obesity, study finds

It is a sight that can make parents despair: their teenage offspring idling away the best years of their lives in front of the TV screen.

But, according to new research, watching a lot of television and playing computer games does not automatically make your child a couch potato.

An analysis of the activity diaries of 1,500 12 to 16-year-olds by Loughborough University found the time that youths spent in front of the box or on the net was a poor indicator of their overall levels of activity.

There was also little evidence to suggest a major link between screen-based entertainment and obesity, says Professor Stuart Biddle, who led the study.

He told the British Psychological Association conference in York that it was important to consider when your child was watching. Viewing between 9pm and 10pm posed little threat to their health because this was when they would normally be relaxing, he said.

But parents should be aware of the time between 3.30pm and 6.30pm, when children exercised most.

"If they are not active during these hours it is very unlikely that they are going to be active at all," he said.

Childhood obesity rates have soared, prompting fears of a generation blighted by diabetes and heart disease. The number of obese children aged two to 10 rose from 9.9 per cent in 1995 to 13.4 per cent in 2004.

The research by Loughborough's School of Sport and Exercise Science, which didn't look at diet, found that one of the biggest causes of young people's sedentary lifestyles was the growth in the amount of time spent in the car - now an average 40 minutes a day. This had been accompanied by a dramatic decline in walking or cycling to school.

One of the reasons was that children had to travel further each day as a result of changes in education policy, Professor Biddle said. The loss of this active time had a serious effect on children's lifestyle. "If kids are not walking to school it may not seem a lot but it adds up to a great deal," he said.

The Government recommends each child should do an hour of moderate to vigorous exercise each day. A 15-minute walk to and from school would account for half of the recommended activity. Professor Biddle said this type of exercise was more important to overall good health than the compulsory two hours of timetabled PE they do each week at school.

"Parents are crucial in this. They have to ask themselves, are they encouraging their child to go in the car? Can they get their children to reduce their screen-based behaviour during daytime?" he said.