Woolford SJ, Sidell M, Else V, et al. - The body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) of youths aged 5 to 17 years during the pandemic in 2020 was compared with BMI in the same period prior to the pandemic in 2019.

• Using Kaiser Permanente Southern California (KPSC) electronic health record data, researchers retrieved racially and ethnically diverse cohort (n = 191,509) for this retrospective study (10.4% Asian and Pacific Islander, 50.4% Hispanic, 7.0% non-Hispanic Black, and 25.3% non-Hispanic White); 49.6% of the cohort comprised girls; the mean age was 11.6 years (SD, 3.8 years), and the mean pre-pandemic BMI was 20.7 (SD, 5.4).

• Youths in KPSC had a significant weight gain during the COVID-19 pandemic; this was especially evident among the youngest children.

• Among 5- through 11-year-olds, the increase in overweight or obesity occurred from 36.2% to 45.7% during the pandemic, indicating an absolute increase of 8.7% and relative increase of 23.8% compared with the reference period.

• Among 12- through 15-year-olds and 16- through 17-year-olds, the absolute increase in overweight or obesity was 5.2% (relative increase, 13.4%) and 3.1% (relative increase, 8.3%), respectively.

• The findings, if generalizable to the US, are indicative of the fact that the pandemic has resulted in an increase in pediatric obesity.