The Effect of the covid-19 Pandemic on BMI in Children and Adolescents

Background: The Covid 19 pandemic created circumstances that have the potential to increase rates of overweight and obesity. We aimed to assess whether there were significant increases in BMI among a sample of children and adolescents during 2020 compared to the two years prior to the pandemic.

Methods: Retrospective cohort study. All participants were recruited from a single center in the Midwest. The electronic medical records of 8398 children 3-17 years of age who attended 3 consecutive well visits between June 1 and October 31 in 2018, 2019 and 2020 were reviewed. Generalized linear mixed models were used to calculate the differences in BMI means and rates of obesity across the three years.

Results: Between 2019 and 2020, the average BMI for the whole sample increased 4 percentile points (from the 70th to the 74th percentile; p<0.001) as compared to less than 1 percentile point increase between 2018 and 2019 (p=0.008).
The proportion of children with obesity rose from 13% in 2019 to 15.2% in 2020 (p < 0.001) compared to no significant increase from 2018-2019. Significant disparities in BMI were observed between racial and socioeconomic groups.

Conclusion: Significant increases in BMI and in rates of obesity occurred in 2020 in this sample of children and adolescents. We propose that the circumstances surrounding the Covid-19 pandemic are responsible for this increase.