Not mentioned already is that pizza is ubiquitous within the US. Pretty much anywhere you go, you can order pizza from one of Dominoes/Pizza Hut/Papa John's/Little Ceasar's/local pizza shop. If you're supporting events across the company, pizza is the easy choice, especially since it's easy to order in bulk and easy to clean up afterwards. And as already mentioned, it can be made gluten-free or vegan to satisfy most food restrictions.