Not quite the same, but I used to have a coworker who drank a 2L bottle of Mountain Dew every day. Sure enough, he was the one falling asleep in meetings. I'm sure he felt that the caffeine was necessary to keep him awake, but obviously it wasn't solving the problem -- I imagine the sugar was creating the crash, I know I'm much more sleepy if I eat junk, but then again, I don't know, perhaps he had something else going on.