Although coffee has a mild diuretic effect, it doesn't increase the risk of dehydration as you have it with a significant quantity of water.
Roasting coffee beans cause a loss of water and mass, so the longer they are roasted, the more mass they lose, and have less caffeine. So, dark roasts, in fact, have less caffeine.
According to a study where girls aged
12-18 were tracked, there was absolutely no difference in bone health between those who consumed coffee compared to those who did not.
Although regular consumption of caffeine might cause some physical dependence, it doesn't threaten your health as addictive
drugs do. Caffeine withdrawal usually lasts
a few days.
You can feel slightly fresh since you will be ingesting water in the process, but coffee will never get alcohol out of your stomach or prevent you from feeling tipsy.