I used to live on diet soda, but stopped drinking it several years ago because if you have any sort of pain disorder like fibromyalgia or myofascial pain, the aspertame amplifies the pain.

Aspertame is stimulates your pancreas just as regular sugar so if you're diabetic, you're not doing yourself any favors. It also causes MS type symptoms--google it--you'll be shocked. You're far better off drinking regular soda than the diet. One other disadvantage to drinking any soda is that the phosphorus binds to magnesium in your blood making it unavailable for use in your body. If you suffer from depression or anxiety, chances are you're already low in magnesium so you might want to think about that as well.