system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:How did ancient armies manage to provide food for massive armies over long campaigns?

I tried searching for this and didn't find anything. I keep reading about military campaigns of thousands of men over months. Wouldn't they run out of food? What did they eat? How did they replenish? How did they know how much they needed to pack?
gpt
the pillaged from the enemy. steal the food from the farm fields. the goats. the women. if none was around then they would hunt/gather food from the wilderness the last step if no alternative was to ship food in from transports.