There's some positive news in the battle against childhood obesity. A new federal report released Tuesday says obesity rates among low-income preschoolers actually declined between 2008 and 2011. The drop occurred in 19 of 43 states and territories measured by the Centers for Disease Control and Control. The CDC says a decade-long effort by communities, governments and businesses to focus on diet and exercise may be beginning to pay dividends. Childhood obesity rates declined the most in Florida, Georgia, New Jersey, Missouri, South Dakota and the U.S. Virgin Islands.