June 19, 2009
Slightly Overweight Have Longer Lives
The heath risks of obesity have always been something that experts knew about, but a new Japanese study notes that those considered very skinny are even more at risk, and that slightly overweight people have longer lives.
People who are rotund at age 40 have six to seven years longer to live than extremely thin people, whose life expectancy is about five years less than people who were obese, the study noted.
"We had expected thin people would show the shortest life expectancy but didn't expect the difference to be this large," he added.
The study was conducted by a health team led by Tohoku University professor Ichiro Tsuji and surveyed 50,000 people between 40 and 79 in a 12-year research project in the northern Japanese area of Miyagi.
"There had been an argument that thin people's lives are short because many of them are sick or smoke. But the difference was almost unchanged even when we eliminated these factors," Kuriyama said.
A few reasons for the briefer life spans include their increased susceptibility to diseases like pneumonia and the delicate nature of their blood vessels, he noted.
However, Kuriyama stated explicitly that he was in no way encouraging people to overeat in any way.
"It's better that thin people try to gain normal weight, but we doubt it's good for people of normal physique to put on more fat," he said.
The study separated people into four groups according to their body mass index, or BMI, which is determined by dividing weight in by their squared height.
A normal BMI is in the 18.5 to 25 range, while those with a BMI under 18.5 is considered thin.
A BMI of 25 to 30 was considered mildly overweight and an index higher that 30 is considered obese.
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