As has been stated earlier it all depends on your skill sets, environmental factors (weather cold = More calories Desert = more water to digest protiens and fats etc.) and the distance you are planning to cover. Some of my favorite easy to hump (low weight) food stuffs are Oatmeal fortified with cheap protein powder, Pancake mix, and peanut butter. I stuff the oatmeal and pancake mix into Quart or gallon size ziplocks and store both in a single nalgene bottle. The peanut butter can be left in the original plastic jar but I usually reinforce the bottle by wrapping it with heavy duty duct tape which also lets me carry a good amount of duct tape for minimal additional bulk(my favorite being Gorilla Tape). Add some pogey bait (protein bars or candy bars), jerky, dried fruit, and some trail mix for on the go energy and you are pretty well set for calories while minimizing weight. Now these are just some suggestions and your mileage and tastes may vary but these types of things keep for quite a while and pack a good amount of energy, protein, and good fats vs weight,are easy to prep in several different ways and are cheap and easy to get a hold of.
regards,
Joe