Half of all seven-year-olds in the UK are in risk of suffering from poor health in later life due to sedentary lifestyles.

Figures published in the BMJ Open journal show that 50 per cent of children spend an average of 6.4 hours a day sitting down and fail to reach the recommended levels of exercise per week.

The report – the first objective, UK-wide study of children's physical activity levels – also shows that girls are significantly more inactive than boys. Only 38 per cent of all girls achieve current recommendations for daily exercise, compared to 63 per cent of boys.

There are social and demographic variations too - overall activity levels were lowest in children of Asian (Indian, Pakistani and Bangladeshi) origin.

Geographically, Scotland is the most active of UK nations while children in Northern Ireland were the least active.

The study looked at 6,500 children born between 2000 and 2002, with each child being asked to wear a movement monitor. In an average day, each child took 10,229 steps but spent

The research team that compiled the report - lead by Carol Dezateux and Lucy Griffiths from University College London - raised concerns over the findings.

"A key message from the study is that a comprehensive policy response is needed to boost physical activity," a statement said.

"There is also a need to decrease sedentary time among all young children to the levels appropriate for good health."

To see the full report, click here.