Found this online and thought it was interesting; there's a table showing storage of MREs. Also the web site has a LOT of other info -- probably more than you wanted to know.

http://www.mreinfo.com/mre-longevity.html

I'd better dig out that MRE that has been hiding in my kitchen for a few years. <img src="/images/graemlins/crazy.gif" alt="" />

[Edit: Just polished off the cheese tortellini and vegetable crackers with apple jelly (a little runny). About to start in on the fig bar and sip some lemon-lime drink mix. All in all, for being made in 1999, still "tasty".]