> This is just called skipping breakfast. But I guess there was a need for a new fancy term for an old thing.
On the contrary, we need to be reminded of what we've forgotten; and the proof is in the word itself: "break fast" literally means to break your overnight fast. Our forebears understood the concept of "fasting until your first meal" very well.
The fact is that it's almost certain that for the vast majority of people, until the 20th century, "intermittent fasting" was just called "life". Our hunter-gatherer ancestors couldn't count on three solid meals a day, and even the best-fed would almost certainly have gone into periods of "fasting" several times a week just because of the way life was. A few hundred years ago, many people might have their first meal at 10am (after a few hours of work), and their last meal at 4pm.
And that's exactly why it's actually quite healthy. Your body is designed to fast (i.e., run out of glycogen and have to rely on ketosis), the same way it's designed to exercise; and going through life without any fasting turns out to be as harmful as going through life without any exercise.
But the good news is you don't need to do 36-hour fasts to get at least a bit of health benefits, just like you don't need to go running to get health benefits from exercise. A good brisk walk is way better than no exercise at all; and a 16/8 fasting schedule is better than eating constantly from the time you wake up until the time you go to bed.