I have read only briefly on it a few times over the last couple years, and it and CR intrigued me for the (not proven yet?) health effects etc. I have an acquaintance that swears on a form of IF, using fats/bulletproof coffee etc.. he is rocking some serious changes, in that "just converted" health zealot way.
I have had no serious interest in either. Some of it makes sense to me.. but I'm a. too lazy to bother really getting into it.. and b. it feels a little extreme/unnatural to me.. and I'm already playing in the fringe on my workout currently.
If you were interested in either, I wouldn't consider playing around until well, well into maintenance.