16/8 is eating as much as you usually would, but cramming it into an 8-hour period. I generally do all my eating from 11am - 7pm. It helps a little, and I'll take all the help I can get.

As for the sleeping, I'm usually zonked out by 9:30-10.

Intermittent fasting means that you limit the hours of the day that you eat -- in this case he's fasting for 16 hours of the day and allowing food intake for 8 hours.

I presume this means he has two meals -- a late dinner and an early breakfast.

There are other models too, for example 20/4.

And why is that good?

Human growth hormone seems to be raised considerably after fasting for 16-24h which in turn supports strength training right after this period as the muscles grow naturally faster without any kind of "funny" supplements intake. Basically a body hack.

You can go to sleep earlier. I go to bed at 9pm (except Friday+Saturday) and don't set an alarm. Moving my side project work to first thing in the morning instead of late at night has more than doubled my productivity.