One in four Chicago Public Schools students is obese, a local study has found. The Chicago Sun-Times reports that the numbers also indicate that the percentage of kindergartners who are obese has declined steadily since 2003. Researchers at the Chicago Department of Public Health based their findings on physical exam records for more than 88,000 children attending city public schools in kindergarten, sixth grade and ninth grade. Overall, obesity was highest among youngsters in the sixth grade (29 percent) and lowest among kindergartners (20 percent). About 25 percent of ninth graders were obese.