Background: Physical activity (PA), sedentary behaviours (SB) and dietary habits have been the main focus for prevention of childhood overweight and obesity. Recent research has proposed sleep may be another influential factor. This study explored the relationship between sleep duration, PA and SB on rates of overweight and obesity among a sample of Victorian Primary School children.
Methods: Students from 39 primary schools were recruited using a strategic random sampling technique across schools in 26 Victorian Local Government Areas. Trained researchers measured students’ heights, weights and waist circumference. BMI z-scores and weight status were calculated. Participants' sleep duration was collected through self-report of the usual amount of hours slept per/night and were then categorised as sufficient (≥10 hours) or insufficient (<10 hours) sleepers. Seven-day accelerometry was used to calculate daily light intensity PA (LPA), moderate-to-vigorous intensity PA (MVPA) and sedentary time. Participants with at least 3-days of accelerometry monitoring were included in the analyses. Multiple logistic regression analyses were used to examine the relationship between sleep duration and BMI-z, LPA, MPA and SB with adjustments for potential confounders.
Results/Findings: The final sample comprised a total of 289 students (44% male, 56% female); mean age 11.2±1.0 years. A third (33%) were categorised as insufficient sleepers, 25% of these were overweight and 15% obese. The final adjusted regression model indicated that sleep deprivation significantly increased the risk of overweight (OR 1.8, 95% CI: 1.1-2.8) and doubled the risk of obesity (OR 2.2, 95% CI:1.1-4.6) among primary school children.
Conclusions: This study is among the first to utilise objective measures to examine the relationship between sleep duration, PA and SB on rates of overweight and obesity among Victorian primary school children. While direction of causality remains unclear, the strong positive relationship between weight status and sleep deprivation indicates that sleep is an important area for obesity prevention.