Effectiveness of a school-based randomized controlled trial aimed at increasing physical activity time in adolescents.

BACKGROUND: This study aimed to evaluate the effectiveness of obesity prevention educational activities, isolated or combined with the modification of the school environment on total physical activity time. METHODS: This is a school-based randomized controlled trial, conducted with 2511 students from fifth and sixth-grade in Brazil, that employed a parallel, three-group experimental arms: control group (CG), PAAPPAS group (PG) and PAAPPAS-environment group (PEG). During the 2016 school year, the PG received educational activities in the classroom, providing a general basis for a healthy lifestyle. The PEG received the same educational activities and also modifications in the school environment to stimulate physical activity practice during one month. Physical activity was evaluated through a validated physical activity questionnaire. Intention-to-treat analysis was performed to evaluate the rate of change of physical activity time between groups using PROC GENMOD procedure. All analyses were performed using SAS. RESULTS: Total physical activity time increased by 22% in PEG compared with CG (P = 0.003). No difference was observed between PEG and PG (Δ = 60.20 vs. 36.37, respectively; P = 0.27) and between PG and CG (Δ = 36.37 vs. 9.70, respectively; P = 0.23). The proportion of individuals who attended at least 150 min week-1 of physical activity increased in PEG compared with PG (P = 0.04); however, no difference was observed between PEG and CG (P = 0.19) and between PG and CG (P = 0.26). For 300 min week-1, no difference was observed between groups. CONCLUSION: A school-based multi-component intervention including modification of the school environment was effective for increasing physical activity time among adolescents.

Effectiveness of a randomized school-based intervention involving families and teachers to prevent excessive weight gain among adolescents in Brazil.

OBJECTIVE: To evaluate the effectiveness of a school-based intervention involving the families and teachers that aimed to promote healthy eating habits in adolescents; the ultimate aim of the intervention was to reduce the increase in body mass index (BMI) of the students. DESIGN: Paired cluster randomized school-based trial conducted with a sample of fifth graders. SETTING: Twenty classes were randomly assigned into either an intervention group or a control group. PARTICIPANTS: From a total of 574 eligible students, 559 students participated in the study (intervention: 10 classes with 277 participants; control: 10 classes with 282 participants). The mean age of students was 11 years. INTERVENTION: Students attended 9 nutritional education sessions during the 2010 academic year. Parents/guardians and teachers received information on the same subjects. MAIN OUTCOME MEASUREMENT: Changes in BMI and percentage of body fat. RESULTS: Intention-to-treat analysis showed that changes in BMI were not significantly different between the 2 groups (ß = 0.003; p = 0.75). There was a major reduction in the consumption of sugar-sweetened beverages and cookies in the intervention group; students in this group also consumed more fruits. CONCLUSION: Encouraging the adoption of healthy eating habits promoted important changes in the adolescent diet, but this did not lead to a reduction in BMI gain. Strategies based exclusively on the quality of diet may not reduce weight gain among adolescents. TRIAL REGISTRATION: Clinicaltrials.gov NCT01046474.