Whether you're from South Florida and call it soda or you're from Michigan and call it pop, there's a huge market of carbonated beverages, some are caffeinated, some have fruit juice, and few could ever be considered to be good for you. In keeping with the theme of this page, let's make sure to stress that carbonated beverages cannot be included in your 64oz of water required per day. Next, let's make to stress that the selection we're discussing here - is the least problematic of the field, but in the end, the best thirst quencher is WATER.
Let's address the issue of soda pop, particularly diet soda/pop which is widely consumed by gym-goers looking to reduce calories and lose weight. We've already recognized that althought these products contain carbonated water, we are not to include this liquid in terms of hydration. Further, we need to recognize that that many of the sugar-free varieties contain sugar replacements (both natural and sythetic) which may have effects on water-retention and/or bloating. Finally, we need to also address the issue of sodium - each product has different levels.
But perhaps the most important agent in question is Caffeine. Some of our good friends in the Low Carb community, like Jimmy Moore, are suspicious of any overlap between caffeine and insulin response. This topic could prove to be revolutionary, since countless physique-based competitive athletes carb deplete but continue to taking thermogenics and fat-burners LOADED with caffeine and/or caffeine mimicking agents.
There is one soda, which is also favorite of our good friend Jimmy Moore, that not only is caffeine free, but it's also carb-free (sweetened with Sucralose), and sodium free!! This wonder beverage is still not as good as water, but it's a great, sensible treat in a can. The product is called DIET RITE. Take a look at my video from 2010 and crack open a can a.s.a.p.!
As far as whether or not caffeine does have an effect on insulin levels, this is something I plan to ask in the form of a poll question within the next month. I'm actually quite interested to get some guidance on this issue.