Sodas, iced teas, and other sweetened beverages are our biggest source of high-fructose corn syrup—accounting for about two-thirds of our annual intake. New research from the University of California at San Francisco indicates that fructose can trick our brains into craving more food, even when we’re full. It works by impeding the body’s ability to use leptin, the “satiation hormone” that tells us when we’ve had enough to eat.