Even the study's lead author says the findings shouldn't necessarily change people's weight-loss goals.
"This is not meant to suggest that the conventional wisdom is wrong," the Wall Street Journal quotes lead author Katherine Flegal, a senior scientist at the CDC, as saying. Still, it's statistically significant, she points out. "The findings are very consistent across all different ages and continents," she said.
The review concludes that a BMI of 25 to 30 (the World Health Organization's definition of overweight) is associated with a lower risk of death. The analysis included all causes of death in its data. But BMI is a broad measurement that doesn't parse out fat vs. muscle, or the location of extra weight. Both of those factors are key in assessing the healthy weight of an individual, experts say.