in many people’s experience (mine included) there’s phase change sometime in the 48-72 hour mark in which hunger/appetite essentially disappears (some describe it is gone, some as easily ignored background noise)

Personally, I’ve gone more than 14 days several times, I usually start when not feeling very well (and lacking appetite) which makes even the first couple of days trivial.

If you do want to go farther than 36 (at your own risk of course - I am not a medical professional and this is not medical advice) make sure you are well vitamined, well hydrated, and well electrolyted (e.g. with snake juice) - very often, need for some essential vitamin/mineral masquerades as hunger or appetite.

To underline this. People have died starting eating after a long fast. While the risks are probably manageable, and other people have successfully been fasting a full year, do educate yourself on Refeeding syndrome before doing any extended fasts.

https://en.m.wikipedia.org/wiki/Refeeding_syndrome

> more than 14 days several times

Isn't that how anorexics end up unable to eat at all, though? They go so long without eating that the "good" bacteria that permits digestion disappear so they're no longer able to process food.

I am not familiar with the process anorexics go through, but it is likely very different - thousands, possibly hundreds of thousands, do fasting of 2-7 days on a regular basis with no ill effect (on the contrary - often with good effect).

Good bacteria can likely be reinstated by the body itself (the appendix is a cache for them), from food, or if all else fails - by FMT. I’m not an expert on this, and may be wrong, but from a lot of reading - any anorexia symptoms and processes seem to be entirely absent from mindful fasting.