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.

School-based obesity interventions in the metropolitan area of Rio De Janeiro, Brazil: pooled analysis from five randomised studies.

School-based studies, despite the large number of studies conducted, have reported inconclusive results on obesity prevention. The sample size is a major constraint in such studies by requiring large samples. This pooled analysis overcomes this problem by analysing 5926 students (mean age 11·5 years) from five randomised school-based interventions. These studies focused on encouraging students to change their drinking and eating habits, and physical activities over the one school year, with monthly 1-h sessions in the classroom; culinary class aimed at developing cooking skills to increase healthy eating and attempts to family engagement. Pooled intention-to-treat analysis using linear mixed models accounted for school clusters. Control and intervention groups were balanced at baseline. The overall result was a non-significant change in BMI after one school year of positive changes in behaviours associated with obesity. Estimated mean BMI changed from 19·02 to 19·22 kg/m2 in the control group and from 19·08 to 19·32 kg/m2 in the intervention group (P value of change over time = 0·09). Subgroup analyses among those overweight or with obesity at baseline also did not show differences between intervention and control groups. The percentage of fat measured by bioimpedance indicated a small reduction in the control compared with intervention (P = 0·05). This large pooled analysis showed no effect on obesity measures, although promising results were observed about modifying behaviours associated with obesity.

Effectiveness of school-home intervention for adolescent obesity prevention: parallel school randomised study.

Many school-based interventions for obesity prevention have been proposed with positive changes in behaviour, but with unsatisfactory results on weight change. The objective was to verify the effectiveness of a combined school- and home-based obesity prevention programme on excessive weight gain in adolescents. Teachers delivered the school-based primary prevention programme to fifth- and sixth-graders (nine schools, forty-eight control classes, forty-nine intervention classes), which included encouraging healthy eating habits and physical activity. A subgroup of overweight or obese adolescents also received a home-based secondary prevention programme delivered by community health professionals. Schools were randomised to intervention or control group. Intent-to-treat analysis used mixed models for repeated continuous measures and considered the cluster effect. The main outcomes were changes in BMI and percentage body fat (%body fat) after one school-year of intervention and follow-up. Against our hypothesis, BMI increased more in the intervention group than in the control group (Δ = 0·3 kg/m2; P = 0·05) with a greater decrease in %body fat among boys (Δ = -0·6 %; P = 0·03) in the control group. The intervention group increased physical activity by 12·5 min per week compared with the control group. Female adolescents in the intervention group ate healthier items more frequently than in the control group. The subgroup that received both the school and home interventions had an increase in %body fat than in the control group (Δ = 0·89 %; P = 0·01). In the present study, a behavioural change led to a small increase in physical activity and healthy eating habits but also to an overall increase in food intake.

PAAPPAS community trial protocol: a randomized study of obesity prevention for adolescents combining school with household intervention.

BACKGROUND: The prevalence of childhood obesity is increasing at a high rate in Brazil, making prevention a health priority. Schools are the central focus of interventions aiming the prevention and treatment of childhood obesity, however, randomized trials and cohort studies have not yet provided clear evidence of strategies to reduce prevalence of obesity. The aim of this study is to present a protocol to evaluate the efficacy of combining school and household level interventions to reduce excessive weight gain among students. METHODS: The intervention target fifth and sixth graders from 18 public schools (9 interventions and 9 controls) in the municipality of Duque de Caxias, metropolitan area of Rio de Janeiro, Brazil. A sample size of 2500 students will be evaluated at school for their weight status and those from the intervention group who are overweight or obese will be followed monthly at home by community health agents. Demographic, socioeconomic, anthropometric, eating behavior and food consumption data will be collected at school using a standardized questionnaire programmed in personal digital assistant. At school, all students from the intervention group will be encouraged to change eating habits and food consumption and to increase physical activity and reducing sedentary behavior. DISCUSSION: This study will provide evidence whether integration of school with primary health care can prevent excessive weight gain among adolescents. Positive results will inform a sustainable strategy to be disseminated in the health care system in Brazil. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02711488 . Date of registration: March 11, 2016.