pre- cooked rice is good to take since if you dont have water you can throw some in your mouth and let your saliva rehidrate it, ie look at the veitnamese during the war they survived on it, spam is a good long lasting food, as well as empting a few bags of ramen w/packets in a ziplock to save space, me personally im also taking peanut butter, jiffy extra crunchy runs at 190 calories per 2 table spoons and it high in protien, and the fact that i get a crapload of it for free from wic helps too, another thing ive seen in ready to order bug bags is 3000 calorie food bars, kind of expensive but probably most effective considering the space they'll save, but really anything with high calorie content, and a decent shelf life would work.