Reading, writing, arithmetic — and now diet — are the new building blocks for the nation's preschoolers.
Government health officials said Tuesday the nation may have reached a "tipping point" in the fight against steadily rising obesity rates among preschoolers, with nearly 40 percent of the states now reporting at least a slight decrease in obesity rates for low-income children between the ages of 2 and 4.
The Centers for Disease Control and Prevention, which released the new figures Tuesday, reports that about 1 in 8 American preschoolers are considered overweight, with the rates even higher among minority populations. Previous data showed obesity rates rising consistently or staying flat for decades.
"We are beginning to see a tipping point," CDC Director Dr. Tom Frieden said in a conference call with reporters. But, he added, "addressing [the problem] won't be quick and simple. It will turn gradually."
According to new CDC reports, 18 states showed some improvement in low-income preschooler obesity rates, with 21 states showing no change. Three states reported an increase — Pennsylvania, Colorado and Tennessee.
By contrast, previous CDC data from 2003 to 2008 showed an increase in obesity in 24 states, compared to only nine states showed a decrease.
The government study analyzed 11.6 million children from 2 to 4 years old, leaving out data from a handful of states whose information proved to be inconsistent.
"Even if we take [the nonreporting states] into account, we are still seeing progress," said Ashleigh May, author of the new study.
CDC officials said the obesity rates are even more alarming for minorities, with 1 in 5 black children and 1 in 6 Hispanic children considered overweight. Medical studies show that overweight children are five times more likely to struggle with obesity as adults and are more likely to have high cholesterol and asthma as well.
Most of the children surveyed were enrolled in the federal Women, Infants and Children program, which provides food vouchers and other services. It's harder to get national data on preschoolers of more-affluent families, so it's not clear if the trend applies to all young children. But researchers note that low-income children tend to be heavier.
"If you're going to look at the problem of obesity early in childhood, the group at highest risk are low-income kids. That's what makes this data so valuable for understanding trends in this major public health problem," said Dr. Matthew Davis, a University of Michigan researcher.
The biggest declines were in Florida, Georgia, Missouri, New Jersey and South Dakota. Each saw their obesity numbers fall at least 1 percentage point.
"We are so encouraged to see these decreases, even though they are small, in this age group," Dr. Frieden said.
First lady Michelle Obama, who has made the fight against childhood obesity one of her signature issues, hailed the new CDC data.
"Today's announcement reaffirms my belief that together, we are making a real difference in helping kids across the country get a healthier start to life," Mrs. Obama said in a statement released by the White House.
• This article is based in part on wire service reports.