Childhood obesity has increased significantly in the United States during the past four decades. In 1980, about 5 percent of the country’s children between 2 and 19 were experiencing obesity, according to the C.D.C.; as of 2018, more than 19 percent were — and an additional 16 percent were considered overweight. Because children are far more likely to gain an unhealthful amount of weight while out of school over the summer, experts were worried last spring when in-person schooling was suspended indefinitely because of the pandemic. They feared extended closures might “exacerbate the epidemic of childhood obesity and increase disparities in obesity risk,” as researchers from the Mailman School of Public Health at Columbia University and colleagues put it in a paper in the journal Obesity in June 2020. That, in turn, would mean more children living with related conditions such as Type 2 diabetes, hypertension and fatty-liver disease.
Those concerns were warranted, according to a May study in Pediatrics. Based on measurements of body mass index taken for about 300,000 children between the ages of 2 and 17 during visits to the Children’s Hospital of Philadelphia Care Network, researchers found that, on average, between January 2019 and December 2020 the prevalence of obesity increased by almost 2 percentage points overall, from 13.7 percent to 15.4 percent. (In the most recent years for which national data is available, the increase has been 1 percentage point or less.) Black and Latino children, as well as those from families with lower incomes, displayed sharper increases than children from other groups did. Such gains early in life make it more likely that children will have higher B.M.I.s when they grow up. (Obesity already affects more than 40 percent of American adults.) “This isn’t just baby fat that’s going to go away,” says Brian Jenssen, the study’s lead author and a pediatrician at Children’s. “That’s why I think this is so alarming.”