The longest lived among us aren't necessarily those who are of normal weight, says a new study.

According to new research in the Journal of the American Medical Association (JAMA), researchers say that being overweight may lead to a longer life.

The somewhat surprising conclusion comes from an enormous, detailed review of over 100 previously published research papers connecting body weight and mortality risk among 2.88 million study participants living around the world. The new research confirms that obese people, and particularly those who are extremely obese, tend to die earlier than those of normal weight. But the findings also suggest that people who are overweight (but not obese) may live longer than people with clinically normal body weight.

A total of 270,000 people died of any cause during the studies. Scientists found that the significantly obese — a body mass index of 35 or more — had shorter life spans on average than those of normal weight, or BMI of 18.5 to 24.9.

But the scientists also found that people with a BMI of 25 to 29.9 died at slightly lower rates — not higher — than those of so-called normal weight. And they found that those who were mildly obese, with a BMI of 30 to 34.9, died in no greater numbers than their normal-weight peers.

The new report is the largest and most comprehensive review of how weight can influence longevity. Previous studies that have exposed the link in the past, however, have raised questions about whether the overweight advantage is real.

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