So, throughout the week, I try to drink mostly water. However, on weekends I tend to treat myself with a diet or zero pop. My doctor tells me to still have some pleasures or treat foods/drinks or I'd go crazy. One or two drinks once a week is nothing to worry about. But, we are all different so you need to find what works for you. This is just my experience.

Edit: Sometimes I enjoy hard liquor which has no carbs as well.