I fasted for 3 months (One Meal A Day) but I made sure not to run physical healing and shifting titles during that time (like Paragon).
Was doing Ascension for 2 months of that time and it was quite easy to do. I think I was running Stark for the month before those 2 months while on OMAD which was not so difficult either.
I did it this way coming with the knowledge that I used to get quite hungry when I run Paragon or WANTED. And that too since SaintSovereign did say that Paragon and WANTED required nutrition for all the physical benefits.
So that’s my experience. What titles or custom cores are you planning to run?