The prefixes here (or at least tsuwm of them) are those often used to describe governments - as in oligarchy. Which suggests we might also have:

aristophagy - eating only the best food
plutophagy - eating only the richest food
monophagy - eating only one kind of food

Would think of more, but am distracted by tsuwm's "bahself" and the dangers (and orthographical pitfalls) of PoohBahphagy.