Interpreting the DataAlthough Dr. Swithers focuses on the observation that consumption of artificially sweetened beverages correlates with risk for the metabolic syndrome, type 2 diabetes, hypertension, and coronary heart disease, the fact is that the correlation also exists with sugar-sweetened beverages. This argues against the premise of the article title.
It is obvious (and pointed out in Dr. Swithers' article) that correlation is not the same as causation. People who have type 2 diabetes or obesity may be more likely to consume artificially sweetened beverages. A few studies have tried to correct for this potential "reverse causation" by analyzing results separately for subjects with normal or high baseline BMI, but the results are mixed.
A further complication is the "permission" effect. When people know that they have consumed a noncaloric beverage, they may give themselves permission to compensate by overconsuming other foods. The calories saved by forgoing a 12-ounce can of sugar-sweetened soft drink (about 150) are almost insignificant when traded for a large order of french fries (about 500). And that's before you add ketchup, at 15 calories per tablespoon.