I think the standards are going to be there, but calorie count varies. My last couple NG units went with a few "alternate suppliers" for prepack meals which were similar to but not quite the same as regular .gov MREs. They cost the government less and a few had storage issues but better food. Our command took stock of MREs pretty regularly and did some thumbnail surveys of what the troops actually ate and wanted. Thus a lot of the cheaper MRE types simply eliminated some of the stuff which the troops appeared to not want much of anyway.
There is a whole series of meals from Jimmy Dean (the sausage company) which require refrigeration (and can sustain longer when frozen) which I think are more commonly issued by the Navy and Air force. They are microwave heatable and are edible out of the packaging, just not that good unless the main courses are nuked.
