The COVID-19 pandemic has been associated with weight gain among adults, but little is known about the weight of US children and adolescents. To evaluate pandemic-related changes in weight in school-aged youths, we compared 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 to the same period before the pandemic in 2019.
Youths gained more weight during the COVID-19 pandemic than before the pandemic (Table). The greatest change in the distance from the median BMI for age occurred among 5- through 11-year-olds with an increased BMI of 1.57, compared with 0.91 among 12- through 15-year-olds and 0.48 among 16- through 17-year-olds. Adjusting for height, this translates to a mean gain among 5- through 11-year-olds of 2.30 kg (95% CI, 2.24-2.36 kg) more during the pandemic than during the reference period, 2.31 kg (95% CI, 2.20-2.44 kg) more among 12- through 15-year-olds, and 1.03 kg (95% CI, 0.85-1.20 kg) more among 16- through 17-year-olds. Overweight or obesity increased among 5- through 11-year-olds from 36.2% to 45.7% during the pandemic, an absolute increase of 8.7% and relative increase of 23.8% compared with the reference period (Table). The absolute increase in overweight or obesity was 5.2% among 12- through 15-year-olds (relative increase, 13.4%) and 3.1% (relative increase, 8.3%) among 16- through 17-year-olds. Most of the increase among youths aged 5 through 11 years and 12 through 15 years was due to an increase in obesity.