The pop is now sweetened with sucralose.

There is much we still don't understand about how artificial sweeteners may affect humans, but a growing body of research suggests turning to diet soda to feed a sugar craving may not be a good bet. A smart approach is to reduce consumption of sugar, fake or real.

Can your taste buds tell the difference?

This study shows quite nicely that non-caloric sweeteners can alter gut microbes in mice -- a change that has negative metabolic consequences -- and provides preliminary evidence that it can happen in humans too.

The question of what these sweeteners do to our body -- and by what mechanism -- is far from settled, but this study adds to the realization that looking just at calorie counts, without thinking a little more about the actual ingredients, might not be enough to lead to long-term weight control and health.