Is there a difference between canned soda and fountain drinks health wise?
Yes. Fountain soda machines disperse syrup flavor and carbonated water together. Different machines and even areas of the country calibrate the syrup to water ratio differently. If you add ice, that can affect the amount of beverage consumed, and thus can affect the healthiness minutely. So the overall answer is that fountain drinks can be worse or better for you depending on how much syrup is programmed to come out of the machine. Canned soda at the very least will have much more accurate caloric information.