If you think you're better off saving the weight by shopping one meal at a time...
Me, I'd rather carry a whole week's food. It doesn't really weigh that much, and it saves a ton of money.
A pound of dry carbs, some canned veggies, and a way to purify water goes a long way.
I even like to get a can of milk to make a box of pudding for a nice treat once in a while.

Oatmeal for breakfast, rice or noodles for dinner, maybe a sandwich or ramen for a big snack.
I bring a little bag of flour to make camp biscuits and a little fishing kit if I feel like stopping at a lake or stream to relax.

(I'm not saying a pound is good for a week, it's just to think about how far it goes. I've never been one to weigh my food.)