As far as I'm aware IF comes in various forms. I've used a version of the 5/2 diet for lifters that's on this site. Very simply, you eat breakfast and dinner but nothing in between two non-consectutive and non-training days a week. Lots of water, of course, and coffee helps. I think you're meant to have small breakfast and dinner too (I never did though).
I did that for a year or so, but the more muscle I gained the harder the fasting days got. I started out being able to do 12 hours and by the end of the year eight was a struggle. I wasn't doing small breakfasts and dinners either.
Yes, it works but I'd say a very simple carb cycling approach will work too and will be sustainable for longer.
EDIT: I think it's for fat loss, which it did help with, but for me it was more of a controller for body composition because on my non-fasting days my diet was not so fantastic. Plenty of calories, and just about enough protein to add muscle but that's about it. Carb cycling let me actually clean up my diet while still getting heaps of calories and plenty of protein.