I've been told to avoid CAFFIENATED sodas, but that carbonation is NOT a problem. Many europeans for example, drink mostly "fizzy" water.Even my doc told me a favorite beverage for her is a little orange juice (since most of us cannot tolerate a lot) with carbonated water.The reason to avoid caffeine is not because of its stimulant properties, but rather it's DEHYDRATING properties. I've switched over to caffeine free diet drinks (only drink diet b/c I am diabetic). I have around 5 a day and am fine... Eliminating it alltogether did not affect me one way or another. YMMV.