Primary and secundary prevention of obesity: a randomized community trial in schoolchildren from Duque de Caxias, Rio de Janeiro

The prevalence of obesity among children and adolescents is high in Brazil and in the world, being considered a serious public health problem. Schools can be an important link in preventing obesity due to its scope and its scope and its role in forming behaviors. However, interventions in different countries to prevent obesity at school level have shown contradictory results. In this Thesis, a randomized community trial called PAAPPAS (Parents, Students, Health Agents and Teachers for Healthy Eating), conducted with 5th and 6th grade students from eighteen public schools in Duque de Caxias, Rio de Janeiro. The objective was to evaluate the effectiveness of combining primary and secondary intervention to reduce excessive weight gain in adolescents by encouraging healthy eating and increasing physical activity. The main outcome of the study was to reduce excessive weight gain from the intervention group over the control group through interventions that stimulated healthy food consumption, physical activity and reduced physical inactivity during the 2016 school year. Anthropometric measurements and food consumption occured at the beginning and end of the school year. Primary prevention consisted of six sessions of nutrition education and physical activity carried out in schools and the secondary was directed to overweight students, with home-based guidance provided by community health agents. For longitudinal analyzes, mixed linear models were used through the PROC MIXED procedure, which takes into account missing and unbalanced data. The analyzes were performed using the Statistical Analysis System (SAS) software. An analysis was also performed according to adherence to the protocol in the activities in class and according to the performance of home visits by health agents. The mean variation in body mass index did not differ between the control and intervention groups. There was a reduction the percentage of lower body fat in the experiemental group, compared to the control in boys. The intervention group increased physical activity by 12.5 minutes per week compared to control and there was an increase in the food frequency score of health foods only among girls (0.29; p = 0.04). The subgroup with home and school intervention also showed a greater increase in %body fat compared to the control group (0.89; p = 0.01). Behavioral changes combining school and home intervention increased physical activity and healthy eating habits, but did not promote a reduction in weight gain, suggesting the possibility of their increase.