I think I tried my first fast about thirty years ago.
The reasons and rationales for fasting have varied a lot over the years. I won't bother to catalog them. Mostly curiosity about chemical changes in consciousness.
Ketones as neurotransmitters, etc.
My longest fast was about two weeks - less than 100 calories a day, in the form of orange juice and spirulina, plus lots of water. Quite interesting!
Currently, I don't eat for about a day, about once a week, not on any kind of schedule, but just whenever my body says to.
I noticed about twenty years ago that when I do not eat before a highly technical and stressful job, my mind is sharper, I make fewer mistakes, and I work faster. Time seems to expand slightly and I get more done, more easily.
I've yet to combine fasting with any sort of ritual, good idea, thanks.
Finally, all experimental evidence points to mild caloric underconsumption as a sure method of life extension, and is associated with much lower rates of various diseases, so I tend to indulge in areas other than gross consumption of food.
Quality, not quantity.
(Except for chocolate - moderation has limits!!!