I'm a bit non conventional in my trail food. But since I like the taste these keep me eating and drinking. Your mileage may vary but these are my favorites: fritos and/or ruffles potato chips, a PBJ, a bagel, a brownie and/or donut, ham and cheese sandwich, a couple of zone or south beach bars, gels, sports drinks, trail mix, and lemon drops. Try a lot of things before you go. Eat and drink whatever you can and like, because at altitude most of us don't have much appetite or thirst.