Stevia is used as a weight loss aid; for treating diabetes, high blood pressure and heartburn. In foods, stevia is used as a non-caloric sweetener and flavor enhancer.
While the FDA has granted a purified component form of the plant — called rebaudioside A (rebiana) GRAS (generally recognized as safe) status, the FDA hasn't approved whole-leaf stevia or crude stevia extracts for use as food additives because of concerns about possible health effects. In particular, the FDA has concerns about the effects of whole-leaf or crude stevia on blood sugar control, the kidneys, and the cardiovascular and reproductive systems.
In Japan however, it has been used since 1970s with no reports of any adverse reactions.
“But the Japanese don’t consume large amounts of stevia,” notes Douglas Kinghorn, professor of pharmacognosy (the study of drugs from plants) at the University of Illinois at Chicago.
“In the U.S., we like to go to extremes,” adds toxicologist Ryan Huxtable of the University of Arizona in Tucson. “So a significant number of people here might consume much greater amounts.”
The bottom line: If you use stevia sparingly (once or twice a day in a cup of tea, for example), it isn’t a great threat to you. However, if stevia were marketed widely and used in diet sodas, it would be consumed by millions of people in great quantity, and that might pose a public health threat.
Sprite Green uses Truvia which is a combination of of rebiana, and erythritol (which I talked about in my post entitled: Erythritol and Lankanto Substitutes)
From all my research thus far, I would have to the healthiest and safest options for substituting with sweeteners other than sugar are: Truvia and Lakanto, but I am not an expert, make sure you do your own research! It is your body so make sure you know what you are putting into it.
References: FDA database, Web MD, the Wall Street Journal, and goodnutrition.org