With schools under increasing pressure to offer healthier food, the staple on children's cafeteria trays has come under attack over the very ingredient that made it so popular — sugar. Some school districts have gone as far as prohibiting flavored milk, and Florida considered a statewide ban in schools. Other districts have sought a middle ground by replacing flavored milks containing high-fructose corn syrup with versions containing sugar, which some see as a more natural sweetener. Los Angeles Unified, the nation's second-largest school district, is the latest district to tackle the issue. Superintendent John Deasy recently announced he would push...