autophagy

Hi everyone, I'm a type 1 really interested in low carb/keto/fasting & specifically autophagy for all round health, longevity etc. I recently read (in The Switch, Clement & Loberg) the fasting blood sugars should be 4.2-4.9 mm/l for autophagy to actually kick in. Has anyone else heard this...

I really, really need help from people with more fasting experience than me. I am on day 3 of a fast which will end with dinner tomorrow evening. I decided that in order to trigger autophagy I would only drink water, black decaff coffee and herbal/fruit teas. That's it, nothing else...