Isn't the idea that fasting is not starving the non-cancer cells, it if forcing them to switch over to fat ketone bodies as their fuel source, rather than glucose? Plus that the suggested fasting for chemo is intermittent, say a day or two before treatment, and during. Then eat again after treatment (when no longer nauseous).

So as long as one has some body fat, and the metabolic flexibility to access it, fasting should not cause wasting, as those normal cells are not starving?