Soldiers in the field burn a lot of calories, and it's hard to get them to eat enough -- a sharp drop in body weight hurts physical and mental performance.
It's my impression that the Army will put anything into MRE's that they think will be eaten -- if they had to go with 100% candy and cookies, I think they'd do it.
You see the same before and after photos that I do.
Army diets kill these soldiers.