Your first link talks specifically of fasting every other day, and is about rats. That is completely irrelevant to 5 day fasting in humans, whereas [0] is.
Your second link is from 1995; A lot has happened since. Yes, children should probably not fast. Other than that, more recent data (as well as old, but ignored, data) show that water fasting is good for you. And Valter Lango's research (see [0], and google for more) shows that it's actually extremely beneficial in many cases, especially during chemotherapy.
[0] https://www.sciencemag.org/news/2017/02/five-day-fasting-die...