Is Diet Soda the Devil? Don't be too quick to believe the studies saying so By Evann Gastaldo, Newser Staff Posted Sep 5, 2010 10:55 AM CDT 19 comments Comments Don't believe the hype: Diet Coke may not be bad for you. (©quinn.anya) (Newser) – You've probably read about the studies claiming that artificial sweeteners, like those found in diet soda, do more harm than good. But the studies that indicate those types of sweeteners cause weight gain were done with rats (click here or here for two examples), whereas a study done with actual humans showed that those who drank sugar-sweetened beverages over-ate and gained the most weight. In addition, "reviews of safety continue to indicate that these products are safe," writes nutrition expert Susan B. Roberts on the Daily Beast. "Based on my own experience doing comparative research on rats and baboons in nutrition graduate school, I’ll take the results from a careful study of 24 humans over a few cages of rats (however carefully studied) any day," she continues. Other, "observational" studies that link diet soda to weight gain often confuse cause and effect, she adds, and can't be taken very seriously. "It seems reasonable to conclude that (artificial sweeteners) may help prevent weight gain if used wisely."