Researchers at Princeton University have found that HFCS is actually much worse than regular sugar when it comes to causing weight gain. The study found that rats with access to HFCS gained significantly more weight than rats with access to table sugar — even when their caloric intake was the same. A second study by the researchers found that HFCS lead to long-term increases in body fat, obesity, and a rise in triglycerides.
Said Princeton psychology professor Bart Hoebel, “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.”
The rats in the Princeton study became obese by drinking high-fructose corn syrup, but not by drinking sucrose. The critical differences in appetite, metabolism and gene expression that underlie this phenomenon are yet to be discovered, but may relate to the fact that excess fructose is being metabolized to produce fat, while glucose is largely being processed for energy or stored as a carbohydrate, called glycogen, in the liver and muscles.