Abstract
Societal restrictions due to the Coronavirus Disease 2019 (COVID-19), such as the closure of schools, childcare centers, and community programs, were implemented to prevent the spread of the disease and to protect the health and well-being of the population. These mitigation efforts drastically interrupted the day-to-day environments of children and adolescents and influenced how they spent the majority of their waking hours. Evidence shows on days when children and adolescents are in "structured" settings, such as school or other extracurricular programs or day camps, their obesogenic behaviors (i.e., sleep, physical activity, diet, and screen/media time) are more favorable than on days with less structure (e.g., summer days, weekends). Although obesity is driven by complex interactions between environmental, behavioral, biological, and genetic factors, COVID-19 pandemic closures emphasized the importance of daily structure. This short communication used a tertiary examination of the literature to show how societal restrictions and mitigation strategies resulted in significant increases in childhood and adolescent obesity on a global scale and highlights the importance of key underlying principles of the Structured Days Hypothesis (SDH). Closure of schools and other structured programs as a result of COVID-19 exposed youth to prolonged periods of less-structured environments as youth spent considerably more time at home than normal. Societal restrictions and mitigation strategies as a result of COVID-19 inadvertently demonstrated the importance of structure in shaping children's health behaviors and weight-related outcomes. Public health practitioners and researchers should consider this framework in the development of interventions to prevent and treat obesity in youth.