Do I have to serve food at my party?

It's your party, you can fry if you want to.

Sometimes it's fun to cater your party to fit your party's theme. You can do it up big, or just have a bar-b-que. Most of the time food can be used to enhance the mingling and sharing of information. People are sometimes shy, so giving them something to do with their hands and mouths can take some of the pressure off (especially if you are the murderer).

Be adventurous, have a french cuisine for the Aristocratic Matriarch. You can have a buffet for the Cruise You Lose. You can really shock your friends by having a butler serve them in the more snobbish parties (like Dejected Dowager). Only your imagination will hold you back if you really want to have fun.