There has been a big drop in the number of school districts that take money from pop companies and an increase in the number that ban junk food from vending machines, health officials say.
A government survey found that 44 percent of school districts last year banned junk food from vending machines, up from 30ápercent in 2006.
It also found drops in how many districts took a cut of pop sales, received donations from soft drink companies or allowed pop advertising.
Officials also said some schools around the country are dropping out of the new federal lunch program after just one year, complaining that so many students turned up their noses at the healthier meals packed with whole grains, fruits and vegetables that the cafeterias were losing money.
Federal officials said they didn't have exact numbers but had seen isolated reports of schools cutting ties with the $11ábillion National School Lunch Program, which reimburses schools for meals and gives them access to lower-priced food.
Districts that rejected the program say the reimbursement was not enough to offset losses from students who began avoiding the lunch line and bringing food from home or, in some cases, were going hungry.
Districts that leave the program are free to develop their own guidelines.
Nationally, about 31 million students participated in the guidelines that took effect last fall under the 2010 Healthy, Hunger-Free Kids Act.
The findings on pop and junk food come from a detailed survey last year of more than 800 school districts. The national Center for Disease Control and Prevention does the study every six years. Among the findings released Monday:
╗ The percentage of school districts that received a percentage of pop sales receipts fell from 82 percent in 2006 to 69 percent in 2012.
╗ The proportion that allowed companies to advertise soft drinks on school grounds dropped from 47 percent to about 34 percent.
╗ The percentage that got cash, equipment or other incentives from pop companies fell from 52ápercent to 34 percent.