Think that because diet sodas have low calories they help prevent weight gain? Think again! David Zinczenko and Matt Goulding of Men's Health wrote an article on the ugly truth about diet soda:
When confronted with the growing tide of calories from sweetened beverages, the first response is, “Why not just drink diet soda?” Well, for a few reasons:
Just because diet soda is low in calories doesn't mean it can't lead to weight gain.
It may have only 5 or fewer calories per serving, but emerging research suggests that consuming sugary-tasting beverages--even if they're artificially sweetened--may lead to a high preference for sweetness overall. That means sweeter (and more caloric) cereal, bread, dessert--everything.