Interesting - thanks for posting. The difference in cortisol is useful to know about.
A lot of intermittent fasters follow something less extreme: a 16:8 hour fast. You eat normally during an 8 hour window (lunch, a snack, and dinner, for example) and then don't eat for 16 hours (no after-dinner snacks and no breakfast).
spacing out meals does not magically turn the body into a perpetual motion machine