Bad Arguments for Intermittent Fasting

I've been reading a bit on "intermittent fasting," which is basically the notion that your health might improve from occasionally skipping a meal or two (or a day of eating). I'm agnostic on such fasting, and one reason is that I keep seeing this argument:

We modern humans have become acculturated to the three square meals per day regimen. Animals in the wild, particularly carnivorous animals, don’t eat thrice per day; they eat when they make a kill. I would imagine that Paleolithic man did the same. If I had to make an intelligent guess, I would say that Paleolithic man probably ate once per day or maybe even twice every three days. In data gathered from humans still living in non-Westernized cultures in the last century, it appears that they would gorge after a kill and sleep and lay around doing not much of anything for the next day or so. When these folks got hungry, they went out and hunted and started the cycle again.

If you buy into the idea that the Paleolithic diet is the optimal diet for us today because it is the diet we were molded by the forces of natural selection to perform best on, then you should probably also buy into the idea that a meal timing schedule more like that of Paleolithic mean would provide benefit as well.

The bolded phrase strikes me as especially uncertain. The Paleolithic diet was obviously something that humanity was able to survive, in the sense that it didn't totally kill us off, but that doesn't mean that we evolved to perform best on such a diet. Think of it this way: We may have evolved to be able to last for three days without water, but that in no way implies that it is ideal for us to try to drink as little as possible. (I wonder when we'll start seeing "intermittent water" diets purporting to mimic the experience of the Paleolithic hunter who ran out of water and spent three days looking for a new supply.)