Tea, coffee, coke, Mountain Dew. Caffeine or not, you are going to lose the water eventually. Drinking an average amount of caffeine might increase your cycle rate a small amount. I drink them and find that my cycle rate shortens by about 2 hours in a 24 hour period compared to when I am not imbibing quite so much. Then again, I also figured out that because I include them in my intake, I tend to take in more fluids during a 24 hour period, so perhaps it is just the increased volume that is affecting me, and not the caffeine at all.

As for beer, I think we established before that alchohol consumption does tend to stimulate increased kidney function by deregulating a certain control our system would normally have. I recall hearing that back in midieval times most folks drank beer instead of water because the water wasn't terribly healthy, this included children. I can't imagine that they were all dehydrating that badly or something would've changed for certain.

In any case, if you are considering consuming caffeine from a rationing perspective, I doubt that one or two cups a day is going to have such an adverse effect on you that you are going to suffer from it. What's more, I know how poorly I function when I am deprived of my caffeine fix, so it is well worth it for me to imbibe.

I do like milk a lot. Sometimes there's nothing better than a big cold glass to really quench my thirst in a way nothing else can. Same with buttermilk. I can empty a quart carton of buttermilk in about 10 seconds when the urge hits me. I like it really thick and cold, the bavarian style is the best.