I have been eating expired MRE food that is 9 years old for almost a month. This food was not properly stored, it was under the sun. So far no problems. Except for a not so great taste. Keep in mind that all packages are sealed.

P.S. If anybody asks why... the answer is why not. It is not like we have a clue as to what we are really eating, where did it come from and how it was prepared.