Isn't there a saying that the soldiers and horses have not moved, and the food and grass go first? If the troops have sufficient food supply, they can drink and eat meat if possible, such as before or after the war (of course, if they win, they lose, and if they lose, they lose). The most typical example before the war was a passage from the Hongmen Banquet in Historical Records. When Xiang Yu was preparing to attack Liu Bang, he said, "In order to defeat Pei Gong's army, we must fight for the soldiers." Another fact is that Qin Jun drinks a lot of wine to boost his morale before every war. Drink the celebration wine after winning.
If the troops can't supply food, they can only eat wild vegetables and other things to satisfy their hunger. In the reflection, when there is no food to eat, Yuan Shao's troops eat mulberries in Hebei and Yuan Shu's troops eat mussels in Huainan. When there is nothing to eat, it either eats people or collapses automatically.