With just days to go until London hosts the biggest sporting show on earth, the Olympics, a new study has revealed that Britain has one of the most sedentary populations in the world.

Researchers found that the UK has almost twice the proportion of people defined as "inactive" as in neighbouring France.

63.3 per cent of the population fails to meet recommended levels of physical activity, thereby increasing their risk of conditions such as heart disease, diabetes and cancer.

By comparison, 40.5 per cent of US citizens are inactive, despite more than 30 per cent of them being obese.

Few countries in the world have a greater inactivity prevalence than Britain, with the list topped by Swaziland and Saudi Arabia.

Inactivity was defined as not meeting any of the following three criteria: 30 minutes of moderate activity such as a brisk walk, at least five days a week; 20 minutes of vigorous activity at least three days a week; or an equivalent combination of the two.

The findings, part of a series of studies on physical activity published in The Lancet medical journal, suggest that, worldwide, roughly three out of every 10 adults aged 15 and over do too little exercise.