Fasting as opposed to the expected give some sort of energy. It trains the body to cope without food. For me, I do take out my Mondays and Thursdays to fast (Yh, kinda religious) and it somehow keeps me fit and I'm more active at work on days I fast.
However, one must be conscious of not "starving" oneself and should "know how to fast"
Nice article ma'am..I love the simplicity.