Corn Syrup Makes You Fatter Than Sugar Princeton researchers say rat study answers contentious question By Harry Kimball, Newser Staff Posted Mar 24, 2010 10:47 AM CDT 41 comments Comments Sodas, and a researcher. (AP Photo) (Newser) – It may not end the debate, but researchers say they have definitively proven that high-fructose corn syrup is many times more likely to contribute to obesity than sugar. The Princeton team gave one group of rats water spiked with sugar, and another water with corn syrup. Though the sugar water was twice as concentrated as the corn syrup drink, those sucking down the latter gained far more weight. "When rats are drinking high-fructose corn syrup at levels well below those in soda pop, they're becoming obese—every single one, across the board. Even when rats are fed a high-fat diet, you don't see this; they don't all gain extra weight," a researcher tells News at Princeton. Another long-term experiment showed that animals with access to corn syrup gained 48% more weight than a control group, and put on the pounds in areas characteristic of obesity. One possible explanation is that the manufacturing process makes the fructose in corn syrup easier for the body to absorb.