Weight Gain in Children during the COVID-19 Pandemic and the Protective Effect of Lifestyle Intervention in Children with Obesity.

Introduction: School closures due to the COVID-19 pandemic affect children's daily structure, mealtimes, physical activity, and sleeping habits, possibly exacerbating weight gain, particularly in vulnerable children with overweight and obesity. This study aimed to evaluate both perceived and objectively measured weight gain in children in the Netherlands during the COVID-19 pandemic and the effect of prior lifestyle intervention.

Methods: A total of 150 children of the Children, Obesity and Lifestyle during COVID-19 (COLC) study (cohort A) reported perceptions of weight change during the COVID-19 pandemic. Anthropometric data of 65 children with overweight and obesity were collected at the expertise Centre for Overweight Adolescent and Children's Healthcare in the same period (COACH; cohort B).

Results: In cohort A, 43% of children with overweight and obesity perceived weight gain during the pandemic, compared to 15% of lean children. In cohort B, the BMI z-score increased significantly (+0.065 SD) within 5 months. Participation in a lifestyle intervention for >1 year and having parents with Dutch background was associated with less weight gain, specifically in children with obesity.

Discussion/conclusion: In particular, children with overweight and obesity seem to be at risk for accelerated weight gain during the COVID-19 pandemic. Prior long-term participation in a lifestyle intervention protects against this weight gain, which emphasizes the importance of strong support for vulnerable populations during health crises and pleads for wide implementation of lifestyle interventions for children.