Slaves of Spiegel

It is space. Desolate, wild, boundless, huge. In a far distant corner of the universe, in an unnamed galaxy, a small untidy planet hurtles through time.

Candy wrappers from a million stars, printed in a million languages, tumble across the arid ground. Soft drink cans, of every imaginable shape and size, rattle and click together in the solar wind. Here is a half-eaten taco from the planet Glupso in the Mouse Nebula. Here is a styrofoam box which once contained a deluxe cheeseburger from Earth.

Here and there, a circle of rocky outcroppings conceals the landing place of a giant spaceburger, one of those dreaded pirate ships of the cosmos. Here and there, in the shadows, a dark round form can be seen - a fat space pirate, standing guard.

This place is Spiegel, home of the feared and hated Fat Men, whose raids have depleted much of the junk food in the universe. This is Spiegel the notorious, known on a thousand thousand worlds as the sugar vampire, the grease magnet, and the home of the fat guys...

So the Fat Men, commanded by Sargon, "search throughout the universe for the most greasy, heavy, addictive, and calorific foods." They bring three greasy spoon chefs to their planet for an intergalactic cook-off.
Daniel Pinkwater wrote three "Magic Moscow" books: The Magic Moscow, Attila the Pun, and Slaves of Spiegel. It doesn't really matter in which order you read them, but you should (read them). Unless you don't like funny stories. In that case, forget it. Though out of print, Slaves of Spiegel is available in Pinkwater's 5 Novels collection.