Table 1.

Characteristics of included studies

Authors and Study design	Year	Location	Age range (years)	N and statistical analysis	PA measure	SED measure	Sleep measure	Mental health outcome	Main Findings
Carson et al. [33] Cross-sectional	2017	Canada	6–17	4157 (1239 fasting subsample) Linear regression	Accelerometer (Actical, Respironics) MVPA	Questionnaire (Parents/guardians for those aged 6 to 11 years and self-reported by participants aged 12 to 17 years). Screen time	Questionnaire (Parents/guardians for those aged 6 to 11 years and self-reported by participants aged 12 to 17 years). Estimated sleep duration in a 24-h period.	Social and emotional health (Behavioral strengths and difficulties scores)	There was a dose–response pattern between the number of recommendations achieved and social and emotional health. Compared to meeting all three recommendations, meeting none, one, and two recommendations were associated with a higher behavioral strengths and difficulties score in a gradient pattern. Unstandardized beta coefficients and their 95% confidence intervals in parenthesis for meeting 3 > 2 > 1 > 0 recommendations were: 0 (reference group), 0.12 (0.01, 0.24), 0.23 (0.10, 0.37), and 0.34 (0.18, 0.50).
Carson et al. [34] Cross-sectional	2016	Canada	6–17	4169 Compositional data analysis	Accelerometer (Actical, Respironics) LPA and MVPA	Accelerometer (Actical, Respironics) Sedentary time	Questionnaire (Parents/guardians for those aged 6 to 11 years and self-reported by participants aged 12 to 17 years). Estimated sleep duration in a 24-h period.	Social and emotional health (Behavioral strengths and difficulties scores)	The composition of movement behaviours was found to be associated with all health indicators. LPA was positively associated with unfavourable behavioural strengths and difficulties scores, whereas sleep was negatively associated with unfavourable behavioural strengths and difficulties scores.
Dumuid et al. [35] Cross-sectional	2018	Australia, Brazil, Canada, China, Colombia, Finland, India, Kenya, Portugal, South Africa, United Kingdom, and United States	9–11	5855 Compositional data analysis	Accelerometer (Actigraph GT3X+) LPA and MVPA	Accelerometry (Actigraph GT3X+) Sedentary time	Accelerometry (Actigraph GT3X+) Nocturnal sleep duration	Health-related quality of life (KIDSCREEN-10)	The relationship between children’s health-related quality of life and their movement behaviors is moderated by their country’s human development index. In the very high human development index strata alone, health related quality of life was significantly related to the movement behavior composition, with moderate-to-vigorous physical activity (relative to remaining behaviors) being positively associated with health-related quality of life.
Guerrero et al. [36] Cross-sectional	2019	United States	9–10	4524 Structural equation modelling	Questionnaire MVPA	Questionnaire Daily average recreational screen time	Questionnaire (Reported by parents using the Parent Sleep Disturbance Scale for Children) Sleep duration on most night	Impulsivity (UPPS-P Impulsive Behavior Scale34, Behavioral Inhibition System (BIS)/ Behavioral Activation System (BAS) Scale, and cash choice delay discounting task)	Adherence to individual movement behavior recommendations as well as combinations of adherence to movement behavior recommendations were associated with each dimension of impulsivity
Janssen et al. [37] Cross-sectional	2017	Canada	10–17	17,000 Linear regression	Questionnaire MVPA	Questionnaire Average daily screen time	Questionnaire Average nightly sleep duration	Emotional problems, Life satisfaction (Cantril ladder), Prosocial behaviour	Achieving any given recommendation had preferable scores for the health outcomes compared with participants who did not meet the recommendations. There was a dose–response pattern between the number of recommendations achieved and the health outcomes. The adjusted mean and standard errors in parenthesis for meeting 3 > 2 > 1 > 0 recommendations were: 0.72 (0.04), 0.48 (0.03), 0.30 (0.04) and 0.08 (0.07) for emotional problems, −0.82 (0.05), − 0.62 (0.05), − 0.43 (0.05) and − 0.29 (0.09) for life satisfaction, and − 0.37 (0.05), − 0.20 (0.05), − 0.02 (0.06) and 0.11 (0.09) for emotional problems. When the number of recommendations achieved was the same, there were no differences in the health outcomes.
Knell et al. [18] Cross-sectional	2019	United States	13–20	59,397 Logistic regression	Questionnaire MVPA	Questionnaire Average daily screen time	Questionnaire Average nightly sleep duration	Depressive symptoms (2-week sadness), cigarette smoking, alcohol consumption, and cannabis use over the past 30 days	Meeting all 3 recommendations was associated with lower odds of depressive symptoms among males and females, alcohol consumption among females, and cannabis use among males compared to meeting none of the recommendations. Meeting the 3 guidelines was associated with greater odds of smoking cigarette among males compared with meeting none of the recommendations.
Pearson et al. [19] Cross-sectional	2019	United Kingdom	14	3899 Logistic regression	Accelerometer (GENEActiv) MVPA	Questionnaire Screen time on typical weekday	Questionnaire Average nightly sleep duration	Depressive symptoms (Mood and Feelings questionnaire (MFQ))	Meeting all 3 recommendations was associated with lower odds of depressive symptoms among both males and females compared with meeting none of the recommendations.
Sampasa-Kanyinga et al. [38] Cross-sectional	2017	Australia, Brazil, Canada, China, Colombia, Finland, India, Kenya, Portugal, South Africa, United Kingdom, and United States	9–11	6106 Linear mixed models	Accelerometer (Actigraph GT3X+) LPA (not included in statistical analyses) and MVPA	Accelerometry (Actigraph GT3X+) Sedentary time	Accelerometry (Actigraph GT3X+) Nocturnal sleep duration	Health-related quality of life (KIDSCREEN-10)	Children meeting the screen time recommendation, the screen time and sleep recommendation, and all three recommendations had significantly better HRQoL than children not meeting any of these guidelines.
Walsh et al. [20] Cross-sectional	2018	United States	9–10	4524 Linear mixed effects models	Questionnaire MVPA	Questionnaire Daily average recreational screen time	Questionnaire (Reported by parents using the Parent Sleep Disturbance Scale for Children) Sleep duration on most night	Global cognition (Youth NIH Toolbox)	There was a positive gradient between global cognition and each additional recommendation met. Meeting the screen + sleep or screen-only recommendations were the strongest predictors of superior cognition compared to not meeting any recommendations.
Zhu et al. [39] Cross-sectional	2019	United States	6–17	20,708 Logistic regression	Questionnaire All intensities	Questionnaire Daily average recreational screen time	Questionnaire Average weeknight sleep duration	Anxiety and depression (parent- reports)	Meeting all three 24-h movement guidelines was associated with lower odds for anxiety and depression among adolescents compared with meeting none of the recommendations.

PA physical activity, SED sedentary time, MVPA moderate-to-vigorous physical activity, LPA light-intensity physical activity