For an overnight trip, I'd plan food like this: First day out iseasy; just pack a sandwich (bagel sandwiches are more durable). For the evening meal, provided you have a stove, a couple of packets of soup-in-a-cup make a good starter. For your entrée, pack a half pound of frozen ground beef, well wrapped, a small jar of ready-made spaghetti sauce, and half a box of penne pasta. The beef should thaw by the time you get to camp. Sauté it with a little olive oil in your cookpot until browned, add the sauce and a cup of water, then toss in the pasta. Simmer ten minutes, then serve with a little Parmesan cheese and that bottle of Chianti you made your girlfriend lug.
Breakfast can be easy or difficult. For easy, some dried or fresh fruit, a couple of cereal-type breakfast bars (hell, even Pop Tarts will do), and a cup of coffee or hot chocolate. For hard, pack a half-dozen eggs and some cheese and make an omelette or frittata (check out the Chez Gear Guy recipe here). For REALLY hard, also pack an Outback Oven and whip up some breakfast scones. If you're not that far in, and the trail isn't a real steep one, why not pack the extra weight so you can eat well? Pancakes work well, toofigure one cup of pre-mixed batter (minus water, of course) for the two of you. And don't forget the maple syrup.
For lunch that second day, bagels will do nicely. A squeeze-tube of peanut butter should suffice for two, plus an apple or banana and maybe a few pieces of beef or turkey jerky. Keep going during the day by snacking on fresh fruit, maybe some energy bars such as Clif Bars, and a candy bar or two.
That ought to do it. Figure about two pounds of food per person per day, weight-wise, and you'll not go hungry.