I'm pretty sure the study you are thinking of [1] only applies to ages > 65 [2] for which there are a lot of possible explanations. Other studies have found that past a certain age no lifestyle choices matter including smoking & diet since it takes too long to influence when you die.
If you look at [1], a ton of the studies they looked at adjusted for preexisting illness like hypertension and diabetes. It's basically like saying people who fall off sky scrapers don't die of cancer.
It is also important to remember the associated costs and decrease in quality of life associated with being overweight.
That said it is possible the lower-end of the overweight BMI range could be moved up a point or two but that's probably less than the variance between populations anyway.
If you look at [1], a ton of the studies they looked at adjusted for preexisting illness like hypertension and diabetes. It's basically like saying people who fall off sky scrapers don't die of cancer.
It is also important to remember the associated costs and decrease in quality of life associated with being overweight.
That said it is possible the lower-end of the overweight BMI range could be moved up a point or two but that's probably less than the variance between populations anyway.
[1] https://academic.oup.com/ajcn/article/99/4/875/4637868?fbcli...
[2] https://agsjournals.onlinelibrary.wiley.com/doi/abs/10.1111/...