"The first study showed that male rats given water sweetened with high-fructose corn syrup in addition to a standard diet of rat chow gained much more weight than male rats that received water sweetened with table sugar, or sucrose, in conjunction with the standard diet. The concentration of sugar in the sucrose solution was the same as is found in some commercial soft drinks, while the high-fructose corn syrup solution was half as concentrated as most sodas."

http://www.princeton.edu/main/news/archive/S26/91/22K07/inde...

Not saying one two-part study alone is everything, but it's also not nothing.