Dr. Siegel's tips for reducing risk of prediabetes Fox News senior medical analyst Dr. Marc Siegel reacts to a new study showing one in three American teenagers have prediabetes. NEW You can now listen to Fox News articles! A common diabetes drug could dampen some of the key benefits of exercise, a new study has found. Researchers from Rutgers University discovered that adults who took metformin, a widely used generic medication for type 2 diabetes, while exercising saw smaller improvements in