I can't extract anything meaningful from this comment. It seems you are repeating a lot of "go to" sayings about how science should be done in a hand wavy way without understanding the why, then using that to dismiss the results.
For example you say
>There is no causality here; just correlation and many potential cofounders...
what does this specifically mean? When A and B are correlated to statistical significance, either A causes B, B causes A, or something else is causing both A and B. So, how could the future act of living longer be causing people to eat more protein? Or, what possible things could be causing people to eat more animal protein and live longer at the same time? I can't think of anything plausible.
It is fair to say that this study is very good evidence, as good as anything can be, that animal protein is important for longevity.
For example you say
>There is no causality here; just correlation and many potential cofounders...
what does this specifically mean? When A and B are correlated to statistical significance, either A causes B, B causes A, or something else is causing both A and B. So, how could the future act of living longer be causing people to eat more protein? Or, what possible things could be causing people to eat more animal protein and live longer at the same time? I can't think of anything plausible.
It is fair to say that this study is very good evidence, as good as anything can be, that animal protein is important for longevity.