General reboot

Happy you decided to give it a try! :)
I feel too few ppl has fasting in their 'must do at least once' lists. Pls continue sharing your experience.
I am cautious about Science (even though being a scientist myself for the longer portion of my life)
giving deterministic formulation in living systems, with their often subtly changing parameters like "3 days proved safe/beneficial, but not one day". One day is beneficial as well, take my word for it ... which you can probably tell from your own experience now.
Since fasting helped so many people with cancer in the last decades and continues to gain popularity, thanks to our friend the internet, now the chemotherapy market tries to keep its positions by advising it as an adjunct (not a sole) therapy option to chemo- :)
Honestly I am kind of allergic to scientific expressions of skepticism, such as in this article, for a thesis, which the empiric practice had proven countless times during the ages. And nature continues proving it in the animal world. I've had more than 5 medium length fasts, and they all were amazing experiences - physically, spiritually and emotionally.
... everything in a fast gets recycled and renewed, not only the immune systems. You just need to tune your senses to monitor your body, as to get the feeling of the process.