I agree that fasting hits everyone differently, but then, the same can be said of drugs. It's ludicrous to think that one day we will have a drug that mimics the effects of fasting, but without any negative side effects. Whatever drug they come up with in the end, it will have its various effects that hit different people in different ways. Which brings up the obvious point, if the drug does no more than fasting, with whatever side effects fasting raises, then what is the advantage of the drug?