whenever I arrive where I'm going my first stop is often the grocery store. I pick up some peanut butter and any kind of flat bread (regular bread gets too squished in my pack), fruit, nuts, water, liquor, and maybe some instant noodles. The nuts and pb are decent protein. Bread and pb isn't very interesting but it keeps at room temperature and it's easy. I love going out for dinner, but eating all meals out can get pricey and stopping for a few things at the grocery does save money and it's very convenient to have something on hand.

investing in something like a jar of peanut butter is good. ramen noodles are always cheap. but just make sure you are taking vitamins if you are going minimal on food.

summer sausage and a brick of cheese...both will keep for a reasonable amount of time and are damn tasty!....grab some cheap crackers to use as filler..oh, and fruit - especially apples - I'm told that the pectin in apples will make you feel full.

I do a lot of pasta and sauce. Lots of time I get the noodles from the free shelf at hostels. I´m also really big on meat and cheese meals. One of my problems is that I always seem to be thirsty. I try to stop at supermarkets and get liter bottles of water for €1 or less instead of spending more on a smaller botel from a bodega.