Well, I just fasted 60 hours due to appendicitis. It wasn’t because I WANTED to, but because of the not feeling well for a day, then going to the ER, then not being allowed to eat before surgery and during recovery.
I certainly didn’t feel like eating, and it was kinda cool on the autophagy side: I have a lipoma on my foot that was starting to bug me (the size of a marble) and it shrunk dramatically.
So feel free not to eat! However, they may make you eat post-op so they know the system is working before they discharge you from the hospital.