Coffee does not really concern me that much, unless you fill it up with Sugar and it is more sugar water than coffee.
What does concern me is when people get addicted to soft drinks (POP, SODA or whatever it is called in your area). In many cases they contain more caffeine than coffee and with all the sugar, it is dangerous. Even worse, is the soft drinks that are called "diet" with all their chemicals. I cannot handle anything with those artificial sweeteners. Leaves a horrible aftertaste and I will still be gaging 1/2 hour after drinking one. Once asked a co-worker how he handled that after taste and he advised "you get used to it". Don't think I want to be drinking anything that you have to "get used to".