I look at Mormen web sites [they are encouraged to keep a years supply of food on hand] and they emphasize rotating the stock because they say the quality of the food diminishes over time. OK, but who wants to have a steady diet of the kind of stuff that stores well, I don't want to have to eat rice, and dried eggs, and powdered milk until I have to.
But in thinking about it, I wonder if the nutritional value that they worry about declining is mostly the vitamines. I am thinking that the starches and sugars and protein in the food will almost always be there if the food is stored well. So, if I have to rely on foods that I have stashed maybe several years previously, the calories to keep me functioning will still be there, and I will only have to worry about vitamine deficiencies. A much smaller supply of freshly canned or dried fruits and vegetables should suffice to provide them, or even a jar of vitamine supplement pills.