My observation of part the fasting crowd here is that they're endorsing the fast because it does absolutely screw you up and makes you need more pharmaceutical product (since drugs and supplements are now sold by the cartel). I believe they do it on a number of forums for that reason.
So I don't think you can get a real objective opinion about it.
I'm absolutely sure, although our bodies adapted to surviving long periods of starvation, it doesn't mean we should purposefully starve ourselves! I think it's partly the 'elites' proving how stupid humanity can be--heck, they can talk us into starving ourselves to death. A one or two day fast--sure, it could help, but much beyond that I think you seriously start to harm yourself, no matter how 'carefully' you monitor and gauge it.
And the 'elites' cheer with glee---'see we told you---spin it with enough lies and misinformation, and they'll believe anything, even to their lasting harm.' Get rid of those 'useless eaters' (Kissinger), better yet make them get rid of themselves!