Earlier quoted context omitted.
I wondered this as well. In many of the intermittent fasting studies they kept caloric intake the same and showed that the benefits applied even when taking caloric restriction out of the equation.
A lot of diets, especially IF style diets, are pretty much just tricks to get you to eat less calorie wise. Intermittent fasting does this by just setting the simple rule, only eat during a relatively small window of time. It's easier to eat less during that period because there's only so much you can comfortably eat in that time. (Granted you can totally fit a whole day's intake in the IF period but it's harder).
Unless you're a food addict, in which case you can trust me that neither time limitations nor discomfort is an obstacle to filling your gob.