I did a ketogenic diet for a while, and yes I lost weight.

I've talked to quite a few people that have had long term success with such a diet.

But in the end, I didn't feel my best on that diet nor did I feel like it was a good long term solution for me. I'm still working on the long term solution part, but I know that's not it.

The best diet is the one that lets you achieve your goals and one you can sustain for the rest of your life. Otherwise, it's only a temporary solution.