I once herd a TWINKY, you know that golden little cream filled delight you all grew up with in your lunch box, didn't even need an expiration date, as it would out last you!!!
Don't drive your self crazy with this, all you need to do is keep buying the same stuff you always do, but more of it and keep it rotated, try to keep the weight down in case you are forced to move, sure it's a good idea to add things to your menu that will last a little longer, such as rice ,beans, noodles, granola, coffee and (instant) creamer, sugar, corn meal, flour, dried eggs, hard candy, cerial (hot cerial, oat meal, coco weats,ECT.) the list goes on and on, but remember hardly any of this stuff is any good with out WATER!!!
Be realistic if you toss your young child a MRE for dinner they are going to look at you like you are insain, there are a ton of snacks out there for kids like fruit roll ups and yogos and things of that nature, lots of dried fruits and meats is probably a good idea, just be creative don't run to the nearest servival store you will go broke in a heart beat trying to stock that stuff it is very exspensive!!!