Health officials say they have the first evidence of a national decline in childhood obesity.
A government report released Tuesday found at least slight declines in obesity rates for low-income preschoolers in 18 states. Rates went up in three states.
The report is based on the heights and weights of children in a federal food program.
Previous research suggested national childhood obesity rates were flat, though some cities have reported improvements. Nationwide, about 12 percent of boys and girls are obese.