I use a five hour food window. I'm only eating between 4 pm & 9 pm, though I shift the window around a little bit as necessary. That worked pretty well for me when I was doing it before and in hindsight giving it up to try to do P90x and follow that diet was a stupid move, when it was working for me. I also ate like that in high school, too, though I didn't call it intermittent fasting then: I called it too lazy to pack a lunch.
I find that I'm more alert during the day, feel less sluggish overall, and pay more attention to what I'm eating. It eliminates snacking at work, cramming in junk food at lunch, getting take out for breakfast, and other bad habits.