As far as I know, most legitimate sources have urged a combination of dieting and exercise to achieve maximum health and longevity results for fat people. The new research described in this article doesn't exactly dispute that so much as it significantly changes the emphasis. Sort of a change from "diet and exercise" to "exercise and diet". When combined w/ the well known difficulty of keeping lost weight off, the focus on the benefits of exercise could be a game changer, at least for some. In any case, well worth reading.

https://www.nytimes.com/2021/09/29/well ... 029039208a