As many as 600 school districts nationwide now have policies limiting the amount of fat, sugar and salt in food sold at schools, said Jamie Chriqui, a researcher with the Institute for Health Research and Policy at the University of Illinois at Chicago.
School officials want the restrictions to "do for junk food what smoking bans and taxes did for tobacco," Chriqui said.
The restrictions are taking their toll on bake sales, traditionally used to raise money for myriad school activities, The New York Times reported Monday, noting Kentucky has the strictest regulations.
In Piedmont, Calif., the boys water polo team ran through school in their Speedos to promote their bake sale -- once held at school but now held across the street off school grounds.
"I know obesity is a big problem, and it's good the school cares," said Piedmont senior Sam Cardoza. "At the same time, you shouldn't stop a kid from buying a cookie."