A few months ago I suggested that if you drink lots of soda, you might consider switching to club soda instead. Club soda is just water with carbon dioxide pressurized into it. It really isn't that bad to have just plain, but I enjoy a few drops of lime juice in mine, or sometimes I add a tablespoon of the Naked® brand mango smoothie.
Club soda became more important to me when I became pregnant. It is so much harder to stay hydrated when you're pregnant because you need even MORE water than normal, but often having a stomach full of water can make you feel really gross. So I opted more and more for the club soda. I began telling some friends about the club soda option for morning sickness and they really liked it!
But I'd heard reports that there were some bad health effects of club soda. Still, knowing it was better than sugared-cola drinks, I felt it was at least a BETTER choice than the cola syrups or artificially sweetened colas. But I wanted to find out for sure.
Well, there's never really a definitive answer, but I found these articles from respected organizations very reassuring! I'm still pregnant and I'm still going to keep enjoying my club soda!
However, note that there is a difference between Tonic water, club soda, and flavored sparkling water. The tonic water often has a higher sodium content and quinine. The sparkling waters sometimes have artificial sweeteners added. Just go for "club soda." Water and carbon dioxide. You can decide exactly what, if anything, you add to it.