cant happen cause natoiod rations are ment to constipate you (not being able to shit) i had a friend who ate us mres for a week and they had to do surgery on him and cut the rock solid shit out of him. he was 4 days on laxatives so the poor guy could shit again like he use to. this doesnt happen with non natoid mres cause they use publicly available products with the occasional energy bar made for the army but still harmless to normal people. mainly cause they are poor or just rather go shopping for food than to make it themselves.
Austria