I think it can be a cultural thing for what to serve at a birthday party. I have a friend who usually just does cake. Nothing else... no chips, crackers, etc. Just cake. I had a bad migraine and I need food to eat with my pills, and since it wasn't cake time yet I had to ask for a cracker.

My friends and family would flip out if we just served cake. They expect a full meal, so they come hungry!