Many Brazilian children and teens are not getting the recommended sleep

A review found that adequate sleep was reported for fewer than half of preschoolers and adolescents, while estimates varied widely between studies.

Editorial illustration — not from the study.

Researchers combined evidence from population- and school-based observational studies of Brazilian children aged 0 to 18. Average sleep duration fell with age, from 10.50 hours among preschoolers to 7.77 hours among adolescents.

The proportion meeting sleep recommendations differed across studies. Questionnaire-based assessments generally produced higher estimates than movement-based devices, and the guideline used also affected the results. The authors call for more consistent ways to measure and report sleep.

How much children slept

The review included 84 studies with 177,074 participants. The pooled prevalence of adequate sleep duration was 45% among preschoolers, 65% among school-age children and 47% among adolescents. Mean sleep duration ranged from 10.50 hours among preschoolers to 7.77 hours among adolescents, decreasing with age. Studies using questionnaires reported higher estimates than those using accelerometry, a movement-based method for estimating sleep. Estimates also varied according to the sleep guideline used.

Why sleep estimates matter

The findings indicate that many Brazilian children and adolescents do not reach recommended sleep durations. Because insufficient sleep can compromise health and development, clearer and more consistent sleep estimates could help strengthen monitoring and inform public health planning.

Evidence and uncertainties

This was a systematic review and random-effects meta-analysis of population- and school-based observational studies found through eight databases, covering research published through June 2025. The pooled estimates should be interpreted cautiously because differences between studies were substantial, with heterogeneity above 98% in the analyses. Sleep measurement methods and the guidelines used to define adequate sleep also affected the estimates, making comparisons between studies difficult.

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