If I eat plenty of veg and (in my case) red meat 3 or 4 times a week, plus fish, I feel better on every plane of existence, though i don;t mean tot undermine the experiences of people who feel better or like they practice better as vegetarians or even vegans.
Definitely seems like finding a diet in line with your worldview and personal needs boosts your magickal ability though!
I’d say “no junk food,” and it’s generally a good rule (anything beige, starchy/oily combinations, and corn or soy based) but Häagen-Dazs is my secret rocket fuel for heavy pieces of work… 