Abstract
BACKGROUND: The school food environment has a significant influence of the eating habits of children and adolescents because students spend several hours a day at school, where they have at least one meal. The objective of this study was to evaluate the temporal evolution of the food environment of Brazilian public and private schools. METHODS: Study conducted to assess temporal evolution with data about 9th-grade elementary school students, collected from Brazil's National Student Health Survey (PeNSE) of 2012, 2015, and 2019. The school food environment was evaluated using the indicator "Availability of food and beverages in the school food environment". The total score and sub scores were calculated for canteens and alternative food outlets in the areas near schools; higher values represented a healthier environment. Structural and normative characteristics of schools were also analyzed. The variables were described for the national and regional contexts, and according to the location of the municipality (capital or non-capital). All analyses were stratified into public schools or private schools. The analysis was conducted at the student level, since PeNSE does not provide sampling weights for schools. RESULTS: In general, the structural and normative characteristics of schools were stable or improved over the study period. There was a high prevalence of ultra-processed food availability in all study years. Public schools (Brazil as a whole and Southeast macro-region) showed a better food environment between 2012 and 2015, followed by worse outcomes in 2019. On the other hand, in private schools in capital cities the food environment improved between 2015 and 2019. When considering the sub scores, there was an improvement in school canteens between 2015 and 2019 (public schools: Brazil, and North and Central-West regions; private schools: Brazil, North and Northeast regions, and capital cities). However, sub scores of alternative food outlets were worse during the study period (public school schools: Brazil, North and Southeast regions, and capitals and non-capitals). CONCLUSION: There were changes to the food environment of Brazilian schools in less than a decade, and negative changes were more frequent. More effective actions are required to promote healthier food environments within and around schools.