Frankly I think the water-food consumption is fine. Yes, you use kind of alot, but taking in account that you pretty much run all the time, I think it is not too much. Just fill your thirst and hunger ALL the way and you can go a while without having to consume anything.

Same issue here.
Intel i5-2500 @ 3.3GHz
NVidia GTX-550Ti
4gb ram
Win7 64bit

The performance in rural areas is fine, even on higher settings, but when I get into a city, I have to tune my settings down to pretty much low. Really think there's something wrong with that.