Regardless of the method used to sweeten the beverage, Sugar, corn syrup, cane, molasses, it all bad for you. It's all the same to the body--glucose/fructose/sucrose.
Artificial sweeteners are bad, insofar as they turn on your sweet tooth, and make you crave sweet (eating more sugar/sweet). Whether they are "poison" I will not debate, other than to point out there is no clinical evidence they are harmful. There may be an endocrine component to the artificial sweeteners, because even though the number pf products using artificial sweeteners has risen logarithmically in the last few years, the obesity rate continue to climb.
All carbohydrates (starches and sugars) breakdown to glucose, and are identical to the body, metabolically speaking. So a pile of potatoes = a pile of sugar.
/stepsdownfromsoapbox