LiterateGr--I don't think I disagree with you in any material way. At the same time--because of self-selection I do think anything we do along the lines of the weight loss registry is along the lines of representing the cause rather than something somebody should see as proof of efficacy. People will, and have, for low fat, so I do think it's good to get in there just to counter that. We don't need to meet a standard of evidence any better than that of the evidence we're refuting, after all. We do of course, in other places.

I don't discount anecdote--I think any honest anecdote is useful, "if it worked for me, it may work for you" is true even if "if it worked for me, it will work for you" may or may not be in all cases.

Low fat actually did work for me, for the weeks or months I was willing/able to follow it. Low carb is something that I've been able to stick with pretty constantly for well over a decade. So due to probability of compliance, for me personally low carb/ketogenic doesn't really need to be better for me than low fat, it just has to be better than the SAD diet I always defaulted to when low fat was what I did when I was trying to be good.