I did a 60 miler yesterday. My daily rides are usually 1/2 or 1/4 that distance. I had 2 plain croissants before the ride. During the ride, 2 Clif bars and a pretzel. For liquids, 2 water bottles on the bike's cages and 2 more on a handlebar bag, all filled with plain gatorade. I was fine during the ride but felt very very VERY sleepy driving back home. Got home and went to sleep right away.
I've done that same ride before with 3 bars, 3 gels, 2 ham & cheese sandwiches and
accelerade instead of gatorade and a 2ltr camelback with plain water (and lotsa ice)... felt a LOT better. But duno what made the difference, the extra liquids or the extra carbs (or both).