No other type of food can replace the meaning.
Origin was from a clumsy mistake of the tongue. Japanese are damn bastards for making the language so difficult, it's often to have this term slip out of your mouth while speaking, or even singing Japanese.
The mistake has been occurring more and more lately, and it has been spreading further around the globe. From this point, it has transformed part of the internet. This term now can be used in any form. Such as a death threat or a greeting. It can be anything you can think of in your mind and much more.
Person 2: Quite so. I can't handle it anymore... corn me, please.
Heinlein: How unfortunate.