- Best answers
I don't think that's the case. I noticed recently in a siege led by one of the lords of my realm that the defenders where losing numbers each day due to starvation from day one of the siege.It's the developers trying to make the game "Hard" by allowing the AI to cheat. I don't think Prosperity negatively effects their food production, only our own, but under siege, no one has food. You can test this by buying a fief from an Allied Lord, their prosperity will be through the roof but their food production will still be in the positive. If you conquer a town though, they're going to be in the huge negatives of food for a long time, making it hard to put a garrison in place as they'll instantly starve.