A new study has demonstrated that lack of exercise is responsible for twice as many deaths as obesity.

The study conducted by University of Cambridge suggested that a brisk 20 minute walk each day could be enough to reduce an individual's risk of early death.

The study of over 334,000 European men and women found that twice as many deaths may be attributable to lack of physical activity compared with the number of deaths attributable to obesity, but that just a modest increase in physical activity could have significant health benefits.

Physical inactivity has been consistently associated with an increased risk of early death, as well as being associated with a greater risk of diseases such as heart disease and cancer. Although it may also contribute to an increased body mass index (BMI) and obesity, the association with early death is independent of an individual's BMI.

The researchers found that the greatest reduction in risk of premature death occurred in the comparison between inactive and moderately inactive groups, judged by combining activity at work with recreational activity, just under a quarter (22.7 percent) of participants were categorized as inactive, reporting no recreational activity in combination with a sedentary occupation. The impact was greatest amongst normal weight individuals, but even those with higher BMI saw a benefit.