Overall obesity rates among New York City public elementary and middle school students dropped during the past five years, federal health officials say. A report published in the Centers for Disease Control and Prevention\'s Morbidity and Mortality Weekly Report said the weight loss was across all racial and ethnic groups. \"The findings marks the biggest decline in childhood obesity reported by any large municipality in the country,\" the report said. \"Obesity rates among kindergartners through eighth grade -- children ages 5 through 14 -- decreased by 5.5 percent from 21.9 percent for the school year of 2006-2007 to 20.7 percent in 2010-2011.\" The sharpest decline was among children ages 5-6, with a drop from 20.2 percent in the school year 2006-2007 to 18.2 percent in 2010-2011in this age group -- an improvement of almost 10 percent the report said.Despite encouraging trends, one-in-five children in Kindergarten to grade 8 is still obese, CDC officials said.