PARIS • Being overweight shaves about a year off one's life expectancy, a price that soars to about 10 years for the severely obese, a large- scale study reported yesterday.

It refuted earlier findings that carrying a few extra kilos poses no perils. It pointed to evidence that the risk of dying before your 70th birthday grows "steadily and steeply", along with an expanding waistline.

"This study definitely shows being overweight or obese is associated with a risk of premature death," said lead author Emanuele Di Angelantonio at the University of Cambridge.

There is increased risk of coronary heart disease, stroke, respiratory disease and cancer, he said.

Using data from almost four million adults on four continents, the study published in The Lancet medical journal found that overweight people lost about a year of life expectancy on average, and the moderately obese, about three years.

PREMATURE DEATH This study definitely shows being overweight or obese is associated with a risk of premature death. LEAD AUTHOR EMANUELE DI ANGELANTONIO, who adds that there is an increased risk of coronary heart disease, stroke, respiratory disease and cancer in overweight people.

The severely obese lose about 10 years of life expectancy, said Dr Di Angelantonio. That gives a one-in- two chance of dying before 70.

An international team of researchers sifted through data garnered from over 10.6 million people in 239 large studies run between 1970 and last year in 32 countries in North America, Europe, Australia, New Zealand, and East and South Asia.

The collating effort was described as the largest-ever pooled data set on being overweight and mortality. To rule out the impact of other mortality risks, the team excluded current or former smokers, those who had chronic disease at the start of the study and those who died within the first five years. They were left with a sample group of 3.9 million adults.

These were categorised based on body mass index (BMI), a ratio of weight-to-height squared, and the number and causes of death in each group compared.

Under the World Health Organisation (WHO) standard, a BMI of 18.5-24.9 is deemed normal, 25-29.9 overweight, 30-34.9 moderately obese, 35-39.9 severely obese and 40 and over morbidly obese.

The researchers found that the risk of dying before 70 rose from 19 per cent for normal-weight men to 29.5 per cent for those in the moderately obese group, and from 11 per cent to 14.6 per cent for women.

"This corresponds to an absolute increase of 10.5 per cent for men and 3.6 per cent for women - three times as big," said a statement from The Lancet.

The study also found that the excess mortality risk was three times greater in men than in women.

If all overweight and obese people had normal BMI levels, this would eliminate one in five premature deaths in North America, one in six in Australia and New Zealand, one in seven in Europe and one in 20 in East Asia, concluded the study.

It warned that with corpulence spreading worldwide, the high mortality rate in North America "might become typical elsewhere".

The findings contradicted earlier research suggesting that being overweight might not be a mortality risk and might even hold a survival advantage for some groups of people, such as the elderly.

In 2014, according to WHO, more than 1.9 billion adults around the world were overweight. Of those, more than 600 million were obese.

The study also founded an elevated risk of premature mortality among people who were underweight.

AGENCE FRANCE-PRESSE