Just from completely personal experience I can confirm the positive effects - if paired with good food and exercise. I've been doing IF for roughly 3 months now (16 hours fast per day, which is pretty easy to do by skipping breakfast) and combined it with leaving out all the crappy food I ate. You know, the usual gaming/coding/convenience stuff like chips. That and regular sports (rowing) not only resulted in weigh loss (which most likely was just from reduced calorie count, not IF per se) and strongly improved blood pressure (from high to normal). So, at least in my case, the combination of the three factors made a massive difference.

At the same time, I doubt IF by itself would do much if during the rest of the time you ate 3000 calories from chocolate and chips.