The best foods to have in your survival kit are those that are rich in protein. Protein will keep your body satiated for a long time, which means that the food lasts longer. Nuts are one of the best sources of protein out there. They also keep for a long time, making them an excellent addition to your kit. Cashews, almonds and peanuts are all great choices here. Quick tip: Peanut butter is a great way to get protein that tastes good. Throw a jar in your survival kit so that you've got something to look forward to if you ever need to use it.
Your body quickly converts carbohydrates to useable sugar, which makes them a great choice for when you need energy in a hurry. Any kind of crackers will work for this category, but the key lies in selecting those with more nourishing ingredients. Crackers made with whole grains like wheat or rye will replenish your body's energy stores for a longer period of time than buttery and cheesy crackers. Quick tip: raisins and other dried fruits are also great sources of carbohydrates. Spread some peanut butter on a cracker, add a few raisins and you've got a high-calorie supplement that will keep you going.
When you're in survival mode, everything you've heard about diets, food pyramids and calorie-counting should go out the window. Fat is something your body needs to stay warm, so if you're stuck in the wilderness, fat is a very good thing. Summer sausage and pepperoni are great sources of fat (and protein), and the vacuum-sealed rolls last for a year or so. Slice a piece of meat and put it on a cracker, and you've got the survivalist's version of a sandwich. Quick tip: chocolate is also a great source of good fat. It can also be a great morale booster when things are looking grim.