The U.S. Centers for Disease Control and Prevention report was based on a survey of public schools in 34 states that compared results from 2006 to 2008. The study did not report the total number of schools that have changed. Instead, it looked at the proportion of schools in each state.
It found that the median proportion of high schools and middle schools that sell the sugary or salty snacks dropped from 54 percent to 36 percent.
The share of schools that sell soda and artificial fruit drinks dropped from 62 percent to 37 percent.
The improvements were most dramatic in some Southern states. In Mississippi, the proportion selling soda dropped from 78 percent to 25 percent. In Tennessee, it dropped from 73 percent to 26 percent. Those two states also saw dramatic reductions in sales of candy and salty snacks.
The report marked a continued effort by health officials to combat childhood obesity.
"Efforts to improve the school nutrition environment are working and Mississippi and Tennessee are excellent examples of this progress," Howell Wechsler, director of CDC's Division of Adolescent and School Health, said in a statement.
American Heart Association officials celebrated the progress, attributing it to aggressive legislation and school policy changes in some states that they hope will get children and teens accustomed to healthier eating.
"What kids do in school in large measure dictates what they do away from school," said Dr. Clyde Yancy, the association's president.
On the Net:
CDC report: http://www.cdc.gov/schoolhealthprofiles