Well he can only eat 음식 that has 옥수수 starch I think but for now Zim can only eat 와플 but later he might get sick.But he might not if they aren't made 의해 Gir.Who knows what he put in them.
ZIM HATES ALL EARTH 음식 THEY CAUSE HIM PAIN!!! for example beans make him ooze green slime and make his head all big, water(i think that counts as a food) feels like acid to irken people, BUT HE LIKES 와플 TO SOME EXTENT