Also, while I don't find pizza to be at all addictive, my experience is that hamburgers are very much so. I've had experiences where I successfully avoided eating any meat for two months in a row, then succumbed to the temptation of eating a single hamburger and then ate some several times a week for the next month.

Interesting. I just get such consistent meat cravings that I don't even bother trying to not eat meat. I just buy a certain amount and eat it as a basic food group.