MacMeaties is a fast food restaurant featured in many episodes of the Invader Zim series. It is a parody of the McDonald's fast food chain, and is where Zim went for his Career Day field trip after being assigned a life career of fast food preparation. It is also where Mortos first went to power up.
The meat at MacMeaties was supposed to be based on the concept of "space meat"; meat that was developed by NASAPLACE as a germ-hostile food to take on missions into deep space. They originally wanted to sell the said "space meat" at their restaurants, but lacking the money to get access to such high-end technology, they resorted to making their meat out of used napkins.
In the episode "Germs", Zim discovered that the meat they served was completely germ-free, and wore it as clothing at the end of the episode to protect himself from germs.