I need lots of energy but cannot eat normal food (unlike the guys who stop for pizza). I use gu or a knockoff and Accel gel (which has some protein in it) - alternating. I find I actually feel better with the Accel, so I'm not just eating sugar. At breaks, a nab a banana every now and then and peanutbutter on century rides (stored in little plastic bags). To drink, I swear by Cytomax. The key is timing for me - start drinking in first 5-10 minutes - if you wait until you are thirsty, you are dehydrating. I then start a gel in 40 minutes and do every 40 minutes or so (or a banana). Particularly on long rides, you need to keep the fuel up!