Weight Status and Body Composition Dynamics in Children and Adolescents during The Covid-19 Pandemic

Background: The impact of the COVID-19 pandemic on pediatric weight status is unclear. We aimed to examine the change in body composition parameters of children and adolescents during the pandemic.

Methods: An observational study of 220 pediatric subjects (109 boys; mean current age 11.8±3.3years; 37 underweight, 123 normal-weight, and 60 with overweight/obesity) who underwent height and body composition measurements by bioelectrical impedance analysis (Tanita MC-780MA, GMON Professional Software) before and during the pandemic. Height, body mass index (BMI) and muscle-to-fat ratio (MFR) z-scores were calculated. Data collected from the participants’ medical files included home address for socioeconomic position (SEP) calculation, pubertal stage, and self-reported sleep duration and physical activity performance.

Results: The majority of the cohort (81.8%) had stable or improved MFR z-scores during the pandemic. MFR z-scores significantly increased in underweight (p=0.05) and normal-weight subjects (p=0.008), but not in subjects with overweight/obesity (p=0.169). There were significant associations in BMI z-scores (r=0.961, p<0.001) and MFR-z-scores (r=0.854, p<0.001) before and during the pandemic. A multivariate linear regression model identified SEP, pre-pandemic BMI-z-scores, pre-pandemic MFR-z-scores, and physical activity levels during the pandemic as predictors for delta MFR-z-scores (F=12.267, p<0.001). Age, sex, pre-pandemic physical activity, and the time elapsed between initiation of the first nationwide lockdown and BIA assessment did not emerge as predictors for delta MFR-z-score.

Conclusions: Our encouraging findings demonstrate improvement in body composition parameters of underweight and normal-weight subjects and stability in subjects with overweight/obesity. Engagement in physical activity during the pandemic predicted improvement, while lower SEP predicted deterioration.