If size is an issue, try wild rice (I am very excited about it lately). Takes less dry wild rice to yeild the same amount of cooked. You can make it without cooking - just pop it in a ziploc/nalgene with some water about 6 hours before you want to eat.
Larabars (healthy, small, lots of calories). Hummus and crackers. Wild rice, salsa (dehydrated or fresh in packets), cheese, and some dried peppers/onions/etc mixed together. “Kitchens of India” or “tasty bite” http://www.tastybite.com/ ready-made indian/thai food (heavy, takes up space, but a great treat for the first night out). Spaghetti. Rice with chili (you can get chili powder from bulk stores).
Sophie
Sophie