Apparently Tony Horton, the P90X guy suggests dumping coffee, but tea is okay. He is also advocating no alcohol. I don't even have to ask what he thinks about tobacco. Anyway quitting coffee for me (although I take mine black) would be harder than the no alcohol suggestion. He is also wary of OJ, which I used to have each morning . . with my coffee. Oh boy. Ryder13
I am also a coffee addict but I am currently trying to change my diet so I replace coffee by water and sometimes tea. I feel that I have almost the same energy levels as to when I used to drink coffee everyday. Sometimes I would have so much coffee that it would even make me sleepy which is ironic because most people have a lot of energy from it and the sugar high that it gives.
I've never known caffeine to make one sleepy. If I drink a lot of coffee I feel hyperactive and slightly spaced out. Is that what you mean by sleep? The spaced out feeling... Coffee is a drug so be careful and consume sensibly.