Which would mean I need to store food in other regions, but isn't that against the idea of the current trade system?
No.
The current idea of managing food is not GranaryMaster. You don't have to warehouse everything yourself. The current idea is, when you need food, you put out buy orders, or purchase food from sell orders. When you have food, and need gold, you put out sell orders, or fulfill nearby buy orders.
The idea of the current trade system is, when you need something, check the markets.
