Abstract of the abstract: Emerging findings from studies of animal models and human subjects suggest that intermittent energy restriction periods of as little as 16 h can improve health indicators and counteract disease processes.
I naturally go longer than that without eating each day. If you skip breakfast and lunch times, and include the hours you're asleep, it's easy to "fast" for closer to 20 hours or more every day.
I wouldn't force that though, I think everyone is different, living different lifestyles, and their optimal eating cycles will reflect that. When I'm working primarily sedentarily on the computer, then I'd rather work all day and eat quickly in one sitting at the end of the day. But if I'm spending all day doing manual labor outside in the sun, I'll naturally want to eat and drink more in between.