As a former member of the Swedish home guard youth, I was told during a survival exercise that you could eat only freeze-dried food for about two weeks. Young and green as I was, I swallowed the statement without any further thought.
I have come to discover that this statement was not all truth. The recommendation is given by the Swedish military to make sure that soldiers don't go too long without varying their meals. Since the MREs (meals ready to eat) you are getting at the army is somewhat limited in variation, they also recommend that you try to eat plenty of fibre alongside your allotted food rations.
Deciding to test this out by myself I bought the approved MRE (aka. Grönpåsen) for full two weeks. After about a week of nothing but freeze-dried, I felt pretty normal in forms of physical strength and nothing stood out. Aside from the fact that I went to the bathroom about three times in that week, it didn't feel like anything was wrong.
After the full two weeks, I felt that nothing had changed, except the regularity of my bathroom visits (and the fact that I was getting pretty bored with the food). I should probably have ate something rich in fibre on the side to alleviate the lack of it in my diet. This I discovered when I returned to eating normal food, let's just say that I was struck by "Montezuma's revenge" a couple of hours after my first "normal" meal.
So my question is as follows:
What is the maximum time one could live on freeze-dried food and keep a healthy level of nutrients and minerals? Also, how would this diet affect the digestion?