You have most likely heard from everyone that you don’t need any ware houses and while that may be true for more advanced players it’s not for you intermediate level players.
You don't need to have five plus ware houses, but only one. This is mainly because if your alliance went to war with other stronger players you might get attacked. They would also take all your food enabling you to comfort your city. So you need to preserve your food with warehouses. And sometimes the fact of the mater is that it can be simply to late for your alliance to help you in some situations. So that’s where the warehouse comes in, but for it to work properly make sure 100% of the storage is food.