The new federal snack rules don't take effect until the 2014-15 school year, but there's nothing to stop schools from making changes earlier.

Some Minnesota schools already have. Many opted to ban soda pop from vending machine years ago. However, cookies, gummy worms and other sugary treats do remain in some vending machines.

The St. Paul public schools, for example, declared themselves "sweet-free zones" in 2010 after a study found that 40 percent of all fourth-graders were obese.

Anoka-Hennepin schools started supplying concession stands at some of the district's high schools with healthy snacks. They used grant money from the Minnesota Department of Health's Statewide Health Improvement Plan.