LACK of exercise is twice as likely to lead to an early grave than obesity, research has shown.

A brisk 20-minute walk each day is all it takes to avoid dying prematurely, the findings suggest.

Scientists looked at the effects of obesity and exercise on 334,161 European men and women whose progress was followed for 12 years.

They found that people who engaged in moderate levels of daily exercise – equivalent to taking an energetic 20-minute walk – were 16% to 30% less likely to die than those classified as inactive.

Although the impact of exercise was greatest among normal weight individuals, even those with high Body Mass Index (BMI) levels saw a benefit.

Overall, avoiding inactivity theoretically reduced the risk of death from any cause by 7.35%, said the scientists.

Having a BMI lower than obesity levels, defined as a score of 30 or more, was estimated to lower mortality by 3.66%.

Keeping waists trim, irrespective of BMI, had a similar impact on death rates as exercise.

BMI is found by dividing a person’s weight in kilograms by their height in metres squared.