Overweight people live longer

TOKYO: Good news at last for overweight people: those extra kilos may help them live longer.

A study by the Japanese Health, Labour and Welfare Ministry has found that people who are overweight at the age of 40 live longer on average than people with other physiques.

The study showed that thin people had the shortest life expectancy, on average dying six or seven years earlier than overweight people.

Researchers studied the health of about 50,000 people aged 40 or older over a 12-year period. They looked at the past physiques of the participants and how long they lived past the age of 40, and grouped them according to their body mass index (BMI), an indicator of how fat a person is.

Men of regular weight (with a BMI of between 18.5 and 25) at age 40 lived for an average of 39.94 more years, while those who were overweight (BMI of between 25 and 30) at age 40 lived a further 41.64 years.

Women of regular weight lived on average a further 47.97 years, compared with overweight women, who lived another 48.05 years.

Obese men and women (BMI of 30 or more) lived a further 39.41 and 46.02 years, respectively. But thin men (BMI of less than 18.5) were on average expected to live 34.54 more years, and thin women another 41.79 years.

Possible explanations as to why thin people could die earlier include the fact that many thin people smoke and a theory that thin people are more susceptible to contagious diseases.

However, the link between physique and life expectancy is not clearly understood.

"People won't extend their lives by straining to put weight on," said Shinichi Kuriyama, an associate professor at Tohoku University who led the research.

The study also found that the fatter a person is, the greater their medical expenses.

The average lifetime medical expenses for obese men from the age of 40 is 15.21 million yen ($195,000) and 18.6 million for obese women - both 30 per cent higher than for thin people.