No argument. I know the isolated Japanese garrisons resorted to cannibalism to survivej; but that's fresh food, not canned food.
I just finished a memoir of a Marine in WWI. The Marines provided troops for a brigade in the 2nd Division. He spoke frequently of the chronic lack of food, mentioning several times all they would get would be loaves of French bread, maybe a can of tomatoes or a some syrup to eat with the bread. Water supply was an issue, also and cold coffee seemed to be in abundance. He mentioned the company kitchen in most disparaging terms, claiming they looked for any reason not to provide meal service to front line troops. He said there were issued 'Iron Rations" that were not to be eaten without permission and that was if they were in dire straits in combat. It consisted entirely of cans of hardtack, which could not be eaten without soaking it in water, which was also provided sparingly. Rarely, he said, did he enter combat with the hardtack, as they would be so hungry, they would eat it in rear areas even. The US armed services in WWII went to great length to feed the soldiers combat meals, even if they lacking in variety. I've read a good many autobiographies and have written one myself of US soldiers in the Second World War. Rarely did they speak of not having enough food and when they did, it was a transient problem. What they complained about, though, was the monotony of the provided fare. I can understand that, but at least they weren't starving.
Before a big attack did they get a better meal or is it just fiction?? Or depended Upon the Army and war?
He referenced it one time, commenting that they didn't get. From what I could gather, their "better meal" before an attack was just a bit more quantitatively of the usual fare. He groused about the St. Mihel attack in that they were on a road march for about two days and were thrown into the fight without stopping. Eating was almost impossible. Before another attack, they marched several hours in a driving rainstorm and then had to stand, as they could really sit in the mud. He said they had been on their feet for 24 hours before the advance and had not eaten while on the march. The rainstorm made it difficult to eat, plus they were never sure when the stopped, how long they would be there.