Your comment is non-sequitur. Perhaps weight loss is the majority fitness goal in industrialized nations of the world today, but it is still a legitimate and separate topic worth discussing for people who succeed or were never fat in the first place, but still aren't necessarily all that "fit," to think about what they can do to achieve some goal beyond just not being obese.
You'd think Hacker News of all places would understand this. For the majority of the world, simple tech literacy is a goal and presumably a whole lot of research and think pieces discuss that kind of thing, how to best promote it and what not. But everybody here is already tech literate. We want to be technically excellent, not literate. That is a different goal and the tools you need to get there are different.
The above resources are not promoting how to not be obese. They're promoting how to be athletically excellent.