Did you even read the full results of this study? Only extreme BMI categories had strong correlations for increased risk of death and mostly for those who didn'

Did you even read the full results of this study? Only extreme BMI categories had strong correlations for increased risk of death and mostly for those who didn't have a chronic health condition at 50 already: "Among all men and women, including smokers and those with preexisting disease, there was a U-shaped relation between current BMI and the risk of death, with the highest risk in the lowest and the highest categories of BMI. Overweight was not associated with an increased risk of death among men but was weakly associated with an increased risk of death among women." Note that the highest and lowest categories were extreme values of weight for an individual and there were significantly fewer people in those categories compared to the others. Moreover, the authors of this study even talk about being overweight vs. obesity in the discussion section: "However, whether moderate elevations in BMI (i.e., overweight) truly increase the risk of death is controversial.2 Several studies reported no increase in the risk of death among overweight subjects even after those who died during the initial years of follow-up were excluded or subjects were stratified according to smoking status.25-29 Recently, Flegal et al. reported that overweight was not associated with an excess risk of death in the nationally representative samples of U.S. adults drawn from the National Health and Nutrition Examination Survey." They go on to talk about possibilities regarding smokers with the data from this study. Finally, it is worth nothing that this study follow those aged 50 and older and did so through the AARP's health survey and is specifically focused on the health of older people and that is only looking at correlations for individuals who are already at a higher risk of dying in the first place.