Regular soft drinks and many fruit juice beverages and sports drinks are sweetened with added sugars such as sucrose or high fructose corn syrup, while 100-percent fruit juices only contain natural sugars. Milk has natural sugar too, even though it isn’t sweet. Diet soft drinks may taste sweet, but they don’t contain any sugar. “Some dietary recommendations call out ‘sugary’ beverages,” lead researcher Gail Rampersaud told Reuters Health in an email.