Abstract
The interactions between physical activity (PA), screen time, and sleep affect the health of children and adolescents. This study described the national prevalence estimates of German youth aged 9 to 18 years who meet PA, screen time, and sleep guidelines alone and in combination and examined the associations of demographic and personal characteristics with adherence to guidelines. Data from a 2019-2020 German student survey were used (n = 15,786). The target population consisted of children and adolescents enrolled in grades 5-10, with a mean age of 13.0 years (SD = 1.8) and an equal gender distribution (male: 50%). The levels of PA, screen time, and sleep were assessed by self-reports (online questionnaires). The prevalence rates of meeting each guideline individually and in different combinations were calculated, and multilevel logistic regression models were used to examine the associations of demographic and personal characteristics with meeting versus not meeting guidelines. Overall, 9.7% of the respondents met all three guidelines combined, and approximately 25% did not meet any of the guidelines. Half of the participants (50%) met the sleep guidelines, and approximately one third met the screen time (35%) and PA (37%) guidelines alone. Demographic characteristics associated with adherence to meeting all three movement guidelines included younger age, male gender, higher self-reported socioeconomic status, and school type. Personal characteristics related to adherence to meeting all three movement guidelines included better subjective school performance, less frequent attention deficit hyperactivity disorder (ADHD), lower levels of depressive symptoms, lower body mass index (BMI), and not using substances in the past 30 days. CONCLUSION: A low percentage of German children and adolescents met the movement guidelines. With increasing age, the proportion of young people who follow the recommendations decreases. There is an urgent need for health interventions devoted to youth behavior as a whole. WHAT IS KNOWN: • High levels of PA, low levels of screen time, and optimal sleep duration provide enhanced health benefits in comparison to the adoption of just one of these behaviors. • Evidence shows that movement behaviors interact throughout the day and should be studied concurrently. WHAT IS NEW: • Approximately 10% of German children and adolescents met the recommendations on PA, screen time, and sleep, while 25% did not meet any guidelines. • Meeting all guidelines was associated with less frequent ADHD and depressive symptoms, lower BMI, and less frequent substance use in the past 30 days.