Abstract
BACKGROUND: This systematic review examined if the composition of time spent in sleep, sedentary behaviour, and physical activity of different intensities is associated with health and developmental indicators in children aged 0-5 years. METHODS: Four electronic databases (MEDLINE, EMBASE, PsycINFO, and SPORTDiscus) were searched in January 2022. Studies were eligible for inclusion if they were peer-reviewed, the average age of participants was < 6 years, and compositional data analysis was used to examine the associations between the composition of time spent in movement behaviours and health and developmental indicators. RESULTS: Eight studies (7 cross-sectional, 1 prospective cohort) of < 2070 unique participants were included. Only a single study included children < 3 years old and 37% of the associations examined in the literature were based on indicators of body composition. The 24-h movement behaviour composition was associated with mental health indicators (3 of 4 associations examined in the literature), motor skills and development (6 of 7 associations), and physical fitness (3 of 3 associations). Reallocating time from light physical activity into moderate-to-vigorous physical activity was favourable for motor skills and development. Reallocating time from light physical activity into sleep was unfavourable for mental health. Reallocating time from light physical activity into sedentary behaviour or sleep was favourable for motor skills and development. CONCLUSIONS: This review provides some evidence that the composition of movement behaviours is important for the health of young children. Future research should consider including infants and toddlers, larger sample size, and measures of health and development other than body composition. (PROSPERO registration no.: CRD42022298370.).