I hope it's not a fad, as in a dietary sense it is highly effective. I won't go into details, but I will say that unless you understand the
science (at least on a basic level) then don't knock it. The website linked is not about low carb dieting - it is about nutrition science and practice in general (as well as body recomposition, obviously).
My wife was told she was infertile, which had proven true for 5 years - then we caught wind that a no carb diet could help and BAM she was pregnant a month later. Kind of irrelevant, but I think it's pretty amazing.
From a weight loss perspective, my wife and I both had great success with low carb diets.