Longitudinal associations between compliance with 24-hour Movement Behaviour Guidelines and adiposity among European children: results from the IDEFICS and I.Family studies

Purpose: High levels of physical activity (PA), low levels of sedentary behaviour and sufficient amounts of sleep are important for children’s health. This resulted in the launch of integrated 24-hour movement behaviour (24-hMB) guidelines for children. There is a current need to understand children’s adherence to these guidelines, and to investigate how these behaviours interact to influence health. Given that childhood obesity has become a serious public health problem worldwide, this study investigates how compliance with the newly developed 24-hMB guidelines is associated with adiposity in children over time. Methods: Analyses comprised 2,985 children (mean age: 6.20 ± 1.72 years; 49.7% boys) from eight European countries with valid ActiGraph GT3X data (i.e., sleep, light PA, moderate to vigorous PA and total PA) at baseline and 2-year follow-up. Screen time was obtained through a parental-reported questionnaire. Repeated Measures ANOVA were used to analyse if the evolution of BMI z-score (BMIz) and waist-to-hip ratio (WTHR) was associated with trajectories of compliance with the integrated 24-hMB guidelines. Trajectories of compliance were defined as children who: 1) remained compliers (RC), 2) became compliers (BC), 3) became non-compliers (BNC) and 4) remained non-compliers (RNC). Analyses were controlled for socio-economic status and age, and stratified by sex. Results: At baseline, 17.5% of the children complied with the integrated 24-hMB guidelines and 12.3% of the children complied at 2-year follow-up. No difference in evolution of BMIz and WTHR was found between trajectories of compliance in boys (BMIZ: F=1.26, p=0.29; WTHR: F=0.45, p=0.72) and girls (BMIz: F=2.27; p=0.08; WTHR: F=2.32, p=0.08). For trajectories of guideline compliance, a significant main effect for WTHR was observed in boys (F=4.09, p=0.007) with the RNC group having a significant higher WTHR than the RC group (p=0.046) and the BNC group (p=0.006). Conclusion: Low compliance rates with the integrated 24-hMB guidelines in children were observed but guideline compliance was not associated with adiposity indicators over time. However, results suggest that complying with the integrated 24-hMB guidelines over time is beneficial in boys