How are 24-hour movement guidelines linked to health-related quality of life in Spanish children and adolescents?

Background: This study investigates the association between adherence to the 24-h movement guidelines, which include physical activity (PA), screen time (ST), and sleep duration (SD), and health-related quality of life (HRQoL) in a representative sample of Spanish children and adolescents aged 8–14 years. Methods: Data were obtained from the Spanish National Health Survey (2017), a representative cross-sectional survey. The survey employed a three-stage sampling process and included 2711 participants aged 8–14 years after exclusions for missing data. HRQoL was assessed using the modified KIDSCREEN-10 (proxy version). PA, ST, and SD were self-reported by parents and categorized based on international guidelines. Covariates such as age, sex, socioeconomic status, body mass index (BMI), and diet quality were also considered. Robust linear regression models were used to examine associations between the number of guidelines met and HRQoL, adjusting for potential confounders. Results: Overall, a positive dose–response association was observed, with greater compliance with the 24-h movement guidelines linked to higher HRQoL. After adjusting for potential covariates, significant differences in HRQoL were identified on the basis of adherence to the guidelines. Compared with those who complied with one, two, or all three guidelines, participants who adhered to none of the guidelines presented a lower HRQoL. However, significant differences were found only between those who adhered to any of the guidelines and those who followed two (p = 0.003), or all the three (p < 0.001) guidelines. Conclusions: A combination of optimal levels of PA, ST and SD could play a crucial role in enhancing HRQoL among children and adolescents.