How accurate is this article
The progression roughly matches with my understanding of fasting, although I doubt the timeline works out that specific on the hours. That probably depends on your starting point and other factors. If you’re eating low carb or keto to begin with, stages one and two will be far less pronounced or even not apply at all, with stage three then being baseline.
Also not sure about their stage 9. It is my understanding that the immune system is actually repressed during fasting, hence the recommendation to not fast when you get your covid shots (although that might apply more to the early hours).
Stage 10 sounds like some spiritual bologna.