I have loved to cook since I was a child in my mother's kitchen. If I don't have time to cook, I'll just read a cookbook.
Vegetables are a must on a diet. I suggest carrot cake, zucchini bread, and pumpkin pie.
One thing you don't want to do as a host is be running around all evening. Do as much as you can ahead of time, so all you have to do is grill the main ingredients.