The only movies I’ve seen that portrayed military food as awful were films about the American Civil War. OK, MASH too, in both the TV show and movie. But today, we tackle if Hollywood representation is accurate.
For the American Civil War soldier, hardtack was a staple. It was basically bread almost as hard as a rock, so it would not go wrong. It was not unheard of for meat rations at the time (if they could get them) to contain maggots. In fact, it was pretty typical. Extra protein.