Ambiente alimentar escolar: uma análise da efetividade de intervenções e dos aspectos econômicos de cantinas escolares de modelos tradicionais e saudáveis

Abstract

Introduction: The food environment of private schools has been characterized as an obesogenic environment due to the greater availability and advertising of ultra-processed foods. Multicomponent interventions and regulations aimed at restricting the marketing and advertising of these foods in schools seem to hold promise for obesity prevention. However, one of the barriers that can be found to the implementation of healthy canteens is the greater resistance on the part of canteen managers due to the belief in the economic unfeasibility of healthy models. Objective: To analyze the effectiveness of interventions in the school food environment on food consumption and health outcomes of children and adolescents and the economic and commercial aspects of school canteens in a Brazilian metropolis. Methods: A systematic review of randomized or quasi-experimental interventions was conducted, with no restriction on language and date of publication. The analysis of the methodological quality of the studies was performed in duplicate using the ROBINS-I and Rob 2.0 tools. The overall quality of evidence was assessed using the GRADE system. Data were extracted separately, in duplicate, and were pooled using meta-analysis based on fixed or random effect models. Additionally, a case study was carried out that included 36 companies in the school canteen sector in a Brazilian metropolis. Information was collected on the economic, financial, and related aspects of food sold in the canteens through an electronic questionnaire. The classification of items sold in canteens considered the extent and purpose of food processing, according to the NOVA Classification. The characterization and definition of traditional canteens and healthy canteens were proposed considering the percentage of in natura or minimally processed foods and culinary preparations without the presence of ultra-processed foods; the percentage of ultra-processed foods or processed foods or culinary preparations with the presence of ultra-processed foods; and the existence of prohibited foods. The economic and financial analysis was carried out mainly through the evaluation of profitability. Mann-Whitney Test and Fisher's Chi-Square/Exact Test were performed. Results: The systematic review included 21 studies and 10 of them were included in the quantitative synthesis. Interventions were characterized as multi-component in all studies. The greatest reduction in body mass index (Δ z-score) (MD -0.10; 95% CI -0.19, -0.01; I² = 89%) and waist circumference (Δ cm) (MD: -0.67; CI 95% -0.92, –0.41; I² = 17%) were presented by the intervention group. Some of the included studies also showed that interventions can reduce the prevalence of overweight and obesity, waist-to-hip ratio, total cholesterol, triglycerides, and saturated fat intake. However, these results should be interpreted with caution, as the quality of evidence related to the studies ranged from low to moderate. Regarding the case study, 30 canteens were classified in the traditional model (83.33%) and six in the healthy model (16.67%). The median percentage of fresh, minimally processed foods and culinary preparations sold was higher among the healthy model canteens, while the median percentage of ultra-processed, processed foods or preparations with the presence of ultra-processed foods sold was higher in the traditional model canteens ( p<0.05). The results indicated that profitability in healthy canteens was higher compared to traditional ones (p<0.05). Conclusions: Interventions that suggested changes in the school food environment showed limited evidence regarding risk factors for NCDs in children and adolescents, denoting the need for more robust evaluations. In the case study, healthy school canteens showed better financial and economic results compared to traditional canteens, with an emphasis on greater profitability. Thus, to create health-promoting school feeding environments, it is recommended that interventions consistently involve the entire school community, including food and nutrition education in the school pedagogical political project, provide support and training to canteen owners and workers regarding the promotion of adequate and healthy diet, in addition to being fundamental the implementation and monitoring of national regulatory measures that include private schools. It reinforces the need for actions that clarify the economic and financial feasibility of implementing healthy canteens in schools.