Nothing artificial is good for the body! So, here is my answer, just like rlyons remarked: STEVIA, STEVIA, STEVIA....oh, I forgot, one more STEVIA!
There is plenty of research about the safety of this "natural" sweetener to the point that PepsiCo has announced a new line of beverages using stevia. Research suggests that stevia may improve health. Jan Geuns, a biologist in Belgium who has explored the substance's pharmacological effects on humans, points to two Chinese studies that have found stevia can significantly lower blood pressure among people with mild hypertension. Danish researchers have reported that stevia seems to reduce blood glucose levels among patients with type 2 diabetes.
As a second choice and with limited use, I like agave syrup which comes from a cactus plant.