A crackdown on the empty calories in high school vending machines shows healthy results.

Say what you will about “nanny states” and regulations mucking up marketplace dynamics. Often, government standards work as planned: as in reducing the fat, sugar and calories in foods that vending machines spit out in high schools.

For five years, California has enforced nutrition standards on the schools’ so-called competitive foods — basically, any food sold outside of school meal plans. So researchers at the University of Illinois at Chicago crunched data from the Centers for Disease Control on the eating habits of high school students to compare Californians to students in 14 states that set no limits on the junk in junk foods.

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