Wow, I skipped right over this when I was looking for help... although most of my questions are about budgeting, events, or panels.
I actually have something helpful to say here, though! The Marriott has a food delivery service that will order in food from local resturaunts for you. Sadly, it only operates from 6am to 11pm(same as room service). I think taking a break and going out at least once is the way to go... but if you can't tear yourself away you still have options.
Also, this was mentioned in passing, but I wanted to be clear: The rooms at the Marriott have mini-fridges. That means you can have veggies, sandwich fixings, or other cheap nutritous things.
I look forward to seeing you at the Kan!
Thanks,
Val.