For parents, a visit to the pediatrician usually involves a discussion of where their child falls on a growth chart established by the Centers for Disease Control and Prevention.
The old BMI charts were issued in 2000 based on representative data from the 1960s to 1980s. Because of a lack of data, children with obesity weren’t reflected in those charts, which extended to the 97th percentile and a BMI of 37. The new charts extend to a BMI of 60 and indicate how far a child’s BMI is from median measures for children of the same age and sex.
The CDC defines severe obesity as a BMI greater than or equal to 120 percent of the 95th percentile on the BMI-for-age growth charts. A severely obese 2-year-old, for example, would have a BMI above 23, while a severely obese 13-year-old would have a BMI above 31 for girls and 30 for boys.
“I encourage healthcare providers to use the extended growth charts as a tool when working with children and adolescents with severe obesity,” Karen Hacker, director of the CDC’s National Center for Chronic Disease Prevention and Health Promotion, said in a news release. “Intervening early is critical to improving the health of our children as they grow into adults.”
When it comes to children and adolescents without obesity, the previous growth charts won’t change. The CDC decided to retain the existing percentile system to maintain a point of reference for historical measures of BMI and for research comparability purposes.
The rate of obesity among children and adolescents ages 2 through 19 rose from 5.2 percent in 1970-1971 to 19.3 percent in 2017-2018, according to the CDC. Severe obesity rates in the age group increased from 1 percent in 1970-1971 to 6.1 percent in 2017-2018.