Following a 12-year study of over 300,000 people, research published in the American Journal of Clinical Nutrition, warns that a basic lack of exercise could be killing twice as many people as obesity in Europe.
The researchers, from the University of Cambridge, concluded that about 676,000 deaths a year could be attributed to an inactive lifestyle compared to 337,000 from being overweight.
Although obesity and inactivity can often be closely linked, experts say that obese people who take regular exercise are in better health than those who do not and that thin people who have a sedentary lifestyle are at greater risk than those who take even a modicum of exercise each day.
"The greatest risk [of an early death] was in those classed inactive, and that was consistent in normal weight, overweight and obese people," one of the researchers, Prof Ulf Ekelund told BBC News.
He explained that while eliminating obesity rates would cut mortality across Europe by 3.7%, eliminating inactivity would cut rates by 7.5% (676,000 deaths).
Just 20 minutes per day
Prof Ekelund explained that all that would be required to transform health would be a 20 minute walk each day.
"Twenty minutes of physical activity, equivalent to a brisk walk, should be possible for most people to include on their way to or from work, or on lunch breaks, or in the evening instead of watching TV" explained the Norwegian professor, who gets at least 5 hours vigorous exercise from cross country skiing each week.
These findings support the UK Government’s recommendation that adults take 30 minutes of exercise, 5 days a week.