You can burn up to 7,000 calories a day when you do full day hikes: that's over 26 snickers, 2.5 containers of peanut butter, or 12 BigMacs... 12 BigMacs. Sure in "civil" life it is common to worry about how many calories you eat in a day, and you struggle to hit that low 2,000 calorie mark that the government has deemed appropriate and healthy (who actually abides by that?), however, in the back country you STRIVE to hit even 4,000 calories. For all those not so good at math that's a 3,000 calorie deficiency. A few days? Fine. A few weeks? Getting a little famished. A few months? Down right starvation. 4,000 calories is difficult to get you see -- all the calorie dense "junk food" you civilized folk indulge in is just not possible to carry with you on your back for days on end. Along our travels, we have sifted through the masses to figure out what works best.
There are two necessities you must always carry (even if you don't like it normally -- you'll love it after a few days of starving yourself): a jar of peanut butter with a spoon close by, and a bag of GORP (good ol' raisins and peanuts). I hate nuts. I was amazed when stuffed my face with a handful of GORP to find that it rivaled the best steaks I've eaten in terms of taste and satisfaction.
Breakfast would always consist of the following: Camp Drink, which was a mix of instant coffee, hot chocolate, and hazelnut creamer; 4 packs of oatmeal (proportioned of course) with a handful of gorp and a little bit of brown sugar, and a Little Debbies for a morning treat.
After breakfast, its difficult to eat a "lunch". It's a hassle to take off your pack, unpack everything, make lunch, repack, and head off while still have some time to get some decent mileage in. The key to this is snacking. Along with your gorp and the occasional stop for a scoop of peanut butter (which is the food with the highest calorie to weight ratio) you should carry on the side of your pack a couple meal replacement bars, and some candy bars. The candy will give you the sugar boost you need, the meal replacement bar will give you the nutrients you need, and all the other stuff is for energy -- a.k.a. calories. We found the highest calorie bar weighing in at only 3 ounces and giving a whopping 380 calories were ProBars. They are a little pricier, but well worth it. Pacing out your snacks will help keep your energy levels consistent, and keep from slowing you down much.
Dinner is always fun. This is where you are the MOST hungry, and want to stuff yourself until your eyeballs pop out. You need a lot of food, calories, and nutrients. The key is to remember you are not a single serving. Dehydrated and freeze-dried foods like Backpackers Pantry are a great luxury to have, tasty, easy, no real clean-up; if you can bring these with you -- do so. However remember that you need at least the 2-serving meals per person. You'll go to bed hungry if you only eat one! When we couldn't afford that luxury we did one of three things. Stuffing, mashed potatoes, or cous cous. Everything is proportioned in town/home in a ziplock bag (freezer bags are the best). When it comes time to cook, you pour in some boiling water, let sit for a few minutes (note, a few -- not 10, 15, or 20 minutes -- to enjoy immediately), devour your food, roll up the ziplock and you're done with clean-up. For stuffing, we would each eat a box of stovetop with a handful of driedcranberries and a can of chicken. For potatoes (through all our "research" Idahoan was by far the tastiest, most realistic and had the most flavors) a package of instant potatoes, and some bacon bits. Finally, for cous cous, get a flavored cous cous and just add your favorite protein and maybe some raisins. All those options takes minutes to "cook" and being in the ziplocks, there's no dirty pots or dishes. Just a few things to watch out for though: Freeze bags are the most durable. DON'T use a fork -- use a spoon. You'll poke the bottom of the bag and since it's soft from the hot water, can potentially break it. Last but not least, get something to wrap it in -- it keeps it warm as well as keeps your hands from burning. Important things to eat are porteins and frutis. Get dried fruits to eat throughout the day, and get a pack of your favorite protein (spam is disgusting. BUT offers an extra 30 calories per serving than a can of chicken and comes in single serving packages)
We always carried Little Debbies for a high calorie delicious treat for breakfast and dinner. The important thing to remember is drink lots and lots of water. You'll get sick of water for those longer trips, so bring some packets of powdered juice mix or gatorade. Be careful mixing them in your hydration bladders though, if you do decide to hike with a flavored water, make sure to thoroughly wash it out to prevent nasties from building up.
Unfortunately theres no way to carry 7,000 calories worth of food per day, but with these tips you'll go to bed feeling good, and keep going through the day. Happy eating!
p.s. click the picture up top to see our stuffing recipe that was published in Backpacker Magazine-Ian