Children in Britain are among the most lazy in the world, a report claims.
Experts warn a lack of activity can lead to obesity
The survey found UK children spend an average of 9.4 hours a week playing computer games or watching TV, but less than one hour a day being active.
The report, commissioned by Tesco, surveyed 3,500 young people from 10 countries around the world, including Britain, the US, Australia and India.
Ranking the 10 countries in order of their children's fitness, Britain came in as the seventh fittest nation.
Faring even worse were youngsters from Russia and India. South African children came out as the least healthy overall.
At the other end of the spectrum, Australian children proved to be the most fit.
Although, according the survey, they spent an average of ten hours a week in front of a television or games console, they made up for this by playing far more sport than children from other nations.
China came second in the health rankings, and Germany third.
The findings from the Tesco Sport Report mean that the average British child between the age of seven and 16, will spend an average of 4,339 hours - or half a year - in front of a television screen or videogame.
But the survey also revealed that 94% of the children from the Britain said they enjoyed taking part in sport. Swimming was their favourite form of exercise, followed by football and cycling.
A recent report from the Department of Health predicted more than 12 million adults and one million children will be obese by 2010 if no action is taken.
The Health Survey for England also warned 19% of boys and 22% of girls aged two to 15 will be obese by this time.
Dr Ian Campbell, medical director of Weight Concern, said: "A lot of research has shown that our children are much less active than they ought to be, so I find the results of this survey disappointing rather than surprising.
"Obesity in children is a serious issue, and the inescapable fact is that it is about energy in versus energy out."
Stephen Baddeley, Sport England interim chief executive, said: "It is important that people of all ages and abilities are aware of the huge benefits of being active and the role this can play in weight management and in reducing obesity."