US health officials have revised a tool to track rising cases of severe obesity among children that were previously off the charts.
Updated growth charts released Thursday by the Centers for Disease Control and Prevention now extend up to a body mass index of 60 — up from previous charts that stopped at a BMI of 37, with additional categories to track childhood obesity aged 2 to 19 years.
Severe obesity among American children has nearly quadrupled in recent decades, experts said.
“A decade ago, we noticed that we were kind of ahead of our growth charts,” said Dr. Tom Inge, who directs the bariatric surgery program at Lurie Children’s Hospital in Chicago.
CDC charts are the most widely used tool in the US to track children’s growth and development. Parents are used to discussing their children’s growth progress from the time they are babies, noted Dr. Alison Goodman of the CDC. The new charts will be “extremely helpful” in guiding better conversations between parents and health care providers, she said.
“You use these charts as a visual aid,” Goodman said.
The old charts have been in use since 2000. They are based on data from U.S. studies conducted from 1963 to 1994, when far fewer children were obese, let alone severely obese, said Cynthia Ogden, an epidemiologist at CDC. Today, about 4.5 million children – about 6% – fall into this category
Growth charts show patterns of development by age, expressed in BMI, height and weight calculation, and also in curves called percentiles. Unlike adults, children are not classified as obese or severely obese based on a strict BMI cutoff, Inge noted. Instead, children are described as obese based on percentiles – where they fall compared to other children their age.
A child is considered obese if they reach the 95th percentile on the growth charts and severely obese at 120 percent of that mark — or with a BMI of 35 or higher, according to the CDC. For example, a 17-year-old boy who is 5 feet 8 inches tall and weighs 250 pounds would have a BMI of 38 and would be described as severely obese.
The old rankings didn’t include kids like Brian Alcala of Aurora, Ill., who first sought help in 2019 as a high school freshman who stood 5 feet, 5 inches and weighed about 300 pounds.
“That’s when something got out of hand,” recalled Alcala, who had put on extra pounds after developing a rare childhood bone disease that limited his activity.
Children like Alcala, with BMIs of 45, 50 or higher, top the CDC charts, making it difficult to assess their condition or properly chart their progress, often delaying treatment, Inge said.
“It’s like driving a car at night with no headlights and no dashboard,” Inge said. “You don’t know where they are in relation to their peers.”
Alcala, now 17, had weight-loss surgery in April and lost 115 pounds, with 10 more to go. “Everything is going well now,” he said.
However, one expert who questions the use of BMI to assess adults said doctors should be careful when using the new charts with children. They should focus on the behaviors that lead to weight gain while being careful not to stigmatize children and families, said Dr. Tracy Richmond, an associate professor of pediatrics at Harvard Medical School.
“Using it as a visual tool for families I find problematic,” Richmond said. “The family and the child now know that they live in a large body. We clinicians will not provide any new information with this.”
But Erica Alcala, Brian’s mother, said she’s glad the new growth charts will include children like her son.
“Until you see it on paper and in front of you, you don’t know,” she said.