The federally subsidized school lunch and breakfast programs standards were updated in the Hunger-Free Kids Act, passed in 2010 in an effort to combat rising childhood obesity.
The new rules will cover foods sold in vending machines, school stores, and anywhere else students can get food during the school day outside the lunch and breakfast programs. They will not cover homemade lunches or snacks.
"Nothing is more important than the health and well-being of our children," said Secretary Vilsack. "Parents and schools work hard to give our youngsters the opportunity to grow up healthy and strong, and providing healthy options throughout school cafeterias, vending machines, and snack bars will support their great efforts."
As with school meals, other foods sold in schools would have to contain more fruits, vegetables, whole grains, low-fat dairy, and lean protein. Foods high in sugar, sodium and fat will not be allowed, including the sugary sodas and sports drinks found in most vending machines.
The rules make exceptions for "important traditions" including candy or bake sales for fundraising, as well as treats for birthdays, holidays or other celebrations. Foods sold after school, at sporting events for example, will not be subject to the new rules.
Rules will also vary by age group for factors such as portion size and caffeine content. In high school, for example, sodas and sports drinks that contain 60 calories or less in a 12-ounce serving will be allowed.
Elementary and middle schools, however, can only sell only water, carbonated water, 100 percent fruit or vegetable juice, and low fat, fat-free and nonfat flavored milks.
The department said schools and their food and beverage suppliers will have the full school year to implement changes.