If you're trying to lose weight, is it better to drink water, or zero-calorie soda? Temple researchers are conducting what they say is the first head-to-head comparison of the two. "From a calorie point of view, (there is) absolutely no difference," said Gary Foster, director of Temple's Center for Obesity Research and Education. The question is: "What's the collateral effect? If diet beverages have a sweet taste, maybe they get you to crave sweet foods, and that could derail you from you weight-control efforts," Foster said.