ATLANTA -- Health officials say they've seen a big shift in how many school districts take money from soda companies and ban junk food from vending machines.
A survey found 44 percent of school districts banned junk food from vending machines last year, up from 30 percent in 2006.
It also found drops in how many took a cut of soft drink sales, received donations from soda companies, or allowed soda company advertising.
About 17 percent of U.S. children are overweight or obese and that's been holding steady for years. Experts say that diet and exercise at home are at least as important as what happens in school.
The findings come from a detailed government survey last year of more than 800 U.S. school districts.