Diet soda pop seems like a smart way to lose weight because it’s advertised as zero-calorie.  However, many people who drink diet sodas perceive them as healthy which can lead to over-consumption.

Artificial sweeteners found in diet soda such as aspartame are linked to negative health problems like type 2 diabetes, metabolic syndrome, hypertension and stroke. In addition, these artificial sweeteners can affect good gut bacteria which in turn causes insulin resistance and glucose intolerance.

Switching back to regular soda isn't a saving-grace either. Regular sodas are full of added sugars, usually in the form of high-fructose corn syrup. Besides the increased calories and glucose levels, high blood pressure and high triglyceride levels are causes of increased sugar consumption.

What’s the bottom line? The healthiest drink is still water. For extra flavor, add in some fruit like lemon, strawberries, or even try sliced cucumber. If it's the extra boost of energy you're looking for, we recommend green tea or black coffee (without added sugar or creamer).

Sources:

http://time.com