That sounds like a load of crap to me. Most of the parties I go to are family, and the host always takes care of the food. I always ask what I can bring, and if the answer is nothing, I’ll still bring a snack or something that will go with the menu. Nothing huge or overwhelming, but just something that the family will like. It’s always appreciated. But to tell the guests your meal is on you. That doesn’t sound like I’m a guest.