The study, published Friday on the Journal of the America Medical Association (JAMA) Network, found that "youths gained more weight during the COVID-19 pandemic than before it." The greatest change occurred among children aged 5 through 11 years old, which saw a Body Mass Index (BMI) increase of 1.57 and prevalence of obesity increase from 36.2% to 45.7%.
Some experts raised concerns when remote learning started that obesity would increase among children as they lacked certain daily physical activities, such as gym class and recess, as well as differences in meal plans. Now, those children have seen a significant increase in weight that will prove difficult to shed.
A study in May found similar results after researchers measured the BMI for about 300,000 children between the ages of 2 and 17: On average, the prevalence of obesity increased by about two percentage points, going as high as 15.4%.
"This isn’t just baby fat that’s going to go away," Brian Jessen, the lead author on the May study and a pediatrician, told The New York Times. "That’s why I think this is so alarming."
The new JAMA study conducted a "retrospective cohort study" using health record data from southern California. The study looked at children who had an in-person visit with at least 1 BMI measure pre-pandemic and another during the pandemic.
The cohort (or group used in the study) took a healthy cross-section of the population: The group was 10.4% Asian and Pacific Islander, 50.4% Hispanic, 7.0% non-Hispanic Black, and 25.3% non-Hispanic White, and almost half of the children were girls.
The study recommended that researchers should observe if this increase continues or persists so that healthcare providers can determine what intervention may be needed to combat any long-term effects.
The researchers acknowledged that the method of the study can skew results, since it relied on in-person visits, but they argued that the analysis benefitted from the comparisons between the pre-and-during pandemic data.