[bencollier49]

To add to the above, early medieval fasting rules in Christianity were brutal, arguably much tougher than comparable rules from other major religions at the same time. Then we got decadent.

"Noon" is at lunchtime now because the ninth hour (Nones, Noon, 3pm) prayers, after which one could eat, got moved inexorably earlier to cater to the whims of impious monks.

And incidentally, because it's interesting, fasting and veganism without corresponding prayer was/is seen as Satanic, "The fast of the devils", because "fallen angels neither eat nor pray".