(Reuters) - School meals for millions of children in the United States would include less added sugar, more whole grains, and lower sodium content under new standards proposed by the Biden administration on Friday. Agriculture Secretary Tom Vilsack said the updated standards, which would be rolled out over the next several years, were essential to tackling health concerns like childhood obesity and to preparing young people for adult life. "This is a national security imperative. It’s a health care imperative for our children. It’s an equity issue. It’s an educational achievement issue. And it’s an economic competitiveness issue," he said...