Is non-adherence to Canadian 24-h movement guidelines associated with emotional and behavioral difficulties in Brazilian adolescents?

Objective: This study examined the individual and combined association between meeting the 24-h movement guidelines with emotional and behavioral difficulties in Brazilian adolescents. Methods: The study included 815 adolescents (52 % female), aged 11-15 years (mean age: 13.43 years), enrolled in public schools from Jacarezinho, Paraná, Brazil. Sleep duration (SLP) was assessed using the Pittsburgh Sleep Quality Index questionnaire. Screen time (ST) was assessed by self-reported daily use of electronic devices during the leisure time. Physical activity (PA) was measured by accelerometer. Mental health difficulties were assessed using the Strengths and Difficulties Questionnaire. Statistical analyses were performed using generalized linear models, adjusted for age, gender, mother's education level, medication use, and BMI. Results: Findings showed that non-adherence to the ST guideline was associated with higher symptoms of hyperactivity/inattention (β: 1.22; 95 % CI: 1.05; 1.41; n = 815), and non-adherence to the SLP guideline was associated with higher total difficulties (β: 1.08; 95 % CI: 1.00; 1.16; n = 815). Combined analyses indicated significant associations between non-adherence to the PA + ST guidelines with higher emotional symptoms (β: 1.73; 95 % CI: 1.06; 2.83; n = 349), while non-adherence to the ST + SLP was associated with hyperactivity/inattention symptoms (β: 1.32; 95 % CI: 1.07; 1.62; n = 815). Conclusion: Non-adherence to the 24-h movement guidelines was associated with higher symptoms of emotional and behavioral difficulties. Understanding adolescents' lifestyles is crucial for developing efficient policies that enhance mental health among youth.