Surprising New Data on Body Mass Index and Mortality
Data from a recent report published in the Journal of the American Medical Association are about as counter-intuitive as any we're likely to see for a while. Danish researchers calculating body mass index numbers and mortality rates in more than 120,000 people across three time periods (ranging from 1976 to 2013) write that subjects in the study with a BMI of 27 — overweight, by current guidelines — had the lowest risk of dying early from any cause.
More specifically, after finding that people with BMIs within the "normal" range in the first two time periods — 1976-78 and 1991-94 — experienced the lowest mortality, researchers found that those subjects in the last range (2003-2013) with a BMI of 27 were associated with the lowest "all-cause mortality."
"The data are straightforward," said Dr. Borge G. Nordestgaard, a clinical professor at the University of Copenhagen and the author's lead author, quoted in the New York Times. "Thinking about why is more complicated. It may be that we've become better at treating cardiovascular risk factors. But I have no data to support this belief."