Background: International evidence highlights that response rates greatly influence the proportion of children classified as overweight or obese, which is also likely to be true for physical activity (PA) and sedentary behaviour (SB).
Aim: To present the results on adherence to the national PA and SB recommendations among Victorian students in Grades 4, 6, 8 and 10 whom are involved in the Victorian State Government Initiative, Healthy Together Victoria (HTV).
Method: In Term 3, 2014 (Jul-Sept), a total of 2,561 children (RR = 86.6%) in Grade 4 and Grade 6 (mean age 11.0 ± 1.1 years) across 23 local government areas (LGAs) and 3,295 adolescents (RR = 87.5%) in Grade 8 and Grade 10 (mean age 15.1 ± 1.1 years) across 18 LGAs were recruited. These students completed a self-report questionnaire (investigating PA, SB, diet intake and wellbeing) and were invited to have their height, weight and waist measured by trained researchers. Since HTV has a cluster-randomised comparison trial embedded within, cross-sectional analyses were used as there were no significant differences observed between intervention and comparison communities for BMI-z (WHO) at Time 1 (2014). Statistical analyses to examine differences in PA and SB between gender and year levels included chi-square tests and logistic regression.
Results: This study found significantly more boys (15.6% and 22.8%) than girls (8.2% and 8.7%) met the National Physical Activity Guidelines in Grade 4 and Grade 6, respectively (P<0.001). For Grade 8 and Grade 10 students, significantly more boys (13.1% and 11.5%) than girls (4.3% and 4.7%) met the recommendation (P<0.001). Additionally, higher adherence to the screen-time guidelines were reported for younger boys and girls compared to older boys and girls (P<0.001).
Conclusion: This study highlights the successful application of an OPT-OUT consent process in school-based research and concerning patterns in adherence to health-related behaviours.