Adolescent sources of stress, stress levels, and associations between stress and changes in weight outcomes at the time of COVID-19 related school closure in March 2020

•Stress has the potential to affect changes in weight.•Weight changes associated with stress may differ based on starting weight status.•School-based interventions should consider the role of school-related stress.•Stress management techniques may benefit all adolescents. Stress is associated with weight changes, yet how level and sources of stress relate to this association is poorly understood. This mixed methods study examined associations between adolescent stress at the COVID-19 pandemic onset and standardized BMI (BMIz) over a three-month period. Methods: Participants (N = 197, mean age 13.66 ± 1.43 years, 85% Hispanic, 56% female) were recruited from a charter school in Texas to participate in a healthy lifestyle intervention during physical education class. We calculated BMIz using height and weight measurements taken December 2019 and the week of COVID-19 school closures in March 2020. We measured stress in March 2020 with the 4-item Perceived Stress Scale. We ran a multiple linear regression model controlling for baseline BMIz (December 2019), age, sex, intervention condition, and assessed the interaction between baseline BMIz and PSS-4 score on BMIz change. Overall, our sample had an average PSS-4 score of seven and mean BMIz decrease of 0.04 over the three-month period. We observed a significant interaction between PSS-4 score and baseline BMIz. At lower baseline BMIz scores, higher PSS-4 scores were associated with decreases in BMIz over time. There was no significant association at higher baseline BMIz scores. COVID-19 pandemic-related concerns and school performance were the two primary stressors reported. The relation between stress and weight changes differed based on starting weight status. Future interventions should consider the influence of external stressors on intervention adherence and outcomes.