How about enjoying life? I weigh in at a 130lbs at 5'9", and have the body and skin of a woman much younger. Moderation, not abstinence, is where the happiest life is.
You can smoke, do crack and do all sorts of provably harmful things in moderation too. I guess the question is whether all pleasurable things are pleasurable enough to justify the harm they cause. Maybe to you, pop is. I'd say that empirical evidence shows that pop is a clear negative to society, is a recent addition to human diet and isn't universally consumed (so isn't actually necessary to anyone's life), so it seems like it's not far fetched to believe that it's probably not a bad idea to write it off our lives.
Yea, that's kinda what free will is all about. I've made that decision. You're allowed to do whatever you want hun, but abstinence is a fools ideology. You have one life, and the end isn't the good bit.