While childhood obesity remains a serious problem in the United States, an "encouraging" new study finds that obesity rates among low-income preschoolers have declined.
The prevalence of obesity among 2- to 4-year-olds enrolled in the nation's Women, Infants and Children nutrition program fell from 15.9% in 2010 to 13.9% in 2016, according to a study published Tuesday in the medical journal JAMA.
To participate in WIC, children must reside in a household with an income level at a certain percentage below the federal poverty level or be eligible for other child health programs, such as Medicaid, and have nutritional risk determined by a health professional, such as anemia or being underweight.
"This new information gives us hope that our efforts across the US are making a difference," Heidi Blanck, chief of obesity prevention at the US Centers for Disease Control and Prevention and senior author of the study, said of the findings.
"We saw the rates in 2014, which were 14.5%, had come down a little bit from 2010 [at 16%], and now in 2016, they are down to 14%. So we are continually seeing a modest drop. It gives us hope that prevention efforts are making a difference by seeing the numbers continuing to going in the right direction," Blanck said.
Yet "these rates are still too high," she added. "Although good news, all of us have to stay vigilant, because childhood obesity does have short-term impacts on children's physical and mental health."
The study involved health data on 12.4 million children, ages 2-4, who were enrolled in WIC between 2010 and 2016.
The data, which included children's height and weight, came from the WIC Participant and Program Characteristics survey. A calculation of height and weight can measure a person's body mass index, which is used to help diagnose obesity.
The researchers found that the overall prevalence of both overweight or obesity among the children decreased from 32.5% in 2010 to 29.1% in 2016.
"We're also seeing these improvements in all age, sex and race ethnic groups that are part of the WIC population," Blanck said, adding that "disparities among the low-income population are decreasing significantly."
The study had some limitations, including that fewer children were enrolled in WIC in 2010 compared to 2016, and more research is needed to determine whether similar findings would emerge among young children not enrolled in WIC.
"The continued decline in obesity rates among children participating in WIC is encouraging and yet another indication that all eligible families should be able to participate in and benefit from this critical program," Jamie Bussel, senior program officer at the Robert Wood Johnson Foundation, a health nonprofit, said in a statement Tuesday.
She went on to explain some factors that might be driving this decline in obesity rates among young children.
"Recent updates to the nutrition content of the WIC food package -- which the CDC cites as a possible reason for the decline in obesity rates among children participating in WIC -- have led to stores stocking healthier options and families buying healthier foods," she said. "Helping all children grow up at a healthy weight remains one of our top priorities. The data released today are a sign that we are continuing to make meaningful progress toward this goal."