Comercialização de alimentos em cantinas escolares: instrumento de avaliação e disponibilidade de alimentos em escolas privadas brasileiras

Abstract

Introduction: The consumption of ultra-processed foods among children and adolescents has become a growing public health concern worldwide. For children and adolescents, the school environment is considered essential for understanding factors related to food consumption. The sale of unhealthy foods within schools is associated with higher consumption of these products among students. In this context, school canteens are important sources of food access in the school environment and significantly influence the food choices of children and adolescents. However, the evaluation of food sales in Brazilian schools has been limited, either through national surveys on the health of children and adolescents or local studies, often lacking relevant aspects such as detailed characterization of canteens and the foods sold. Objective: Develop, assess the content validity and reliability of an instrument to characterize school canteens and to characterize canteens and food and beverage sales in private schools in Brazil. Article 1: Develop, verify the content validity, and assess the reliability of an instrument for characterizing school canteens and evaluating the commercialization of food and beverages in these spaces. Methods for Article 1: The preliminary version of the instrument was developed after a literature review, identification of food environment dimensions, creation of items, and structuring of the instrument. It was divided into sections: identification and characterization of the canteen and the foods sold. The instrument was evaluated by experts, and a content validity index was calculated for each item (> 0.80 was considered satisfactory). Reliability was assessed in a sample of canteens using inter-observer and intra-observer tests. Kappa, PABAK, and intra-class correlation coefficients were calculated. Results for Article 1: The instrument included 945 items distributed across three sections. The mean CVI score, considering the evaluated aspects (relevance, clarity of item wording, and response options), was 0.95. Suggestions from the experts were evaluated, and items were included, removed, or revised as needed. Regarding reliability, 95.2% of the analyzed items showed excellent, very good, or good agreement (≥0.6). Conclusion for Article 1: The instrument proved to be reliable for assessing the food environment of school canteens in the Brazilian context, showing satisfactory content validity and reliability. This instrument advances the measurement of food sales in canteens, an important aspect of the school food environment. Objective for Article 2: Characterize canteens and food sales in private schools in Brazilian capitals, considering the different macro-regions of the country. Methods for Article 2: A cross-sectional study analyzed data from 2,241 canteens in private elementary and high schools across the 26 Brazilian capitals and the Federal District. Data were collected between 2022 and 2024 using the developed and validated instrument. Indicators such as the Ratio of Ultra-Processed Products (AUPP) to minimally processed foods and preparations (AIMPP) (Raz-AUPP/AIMPP) and the Healthiness Index (HI) were used to assess the availability, variety, and healthiness of foods offered in canteens. Additionally, the percentage of canteens where the average variety of AUPP exceeded AIMPP was calculated. Foods and beverages were classified using the NOVA classification. Data analysis included relative frequencies, means, and their 95% confidence intervals (CIs). Results for Article 2: In Brazil, most canteens have fewer than five employees (77.1%), are outsourced (55.1%), and sell snacks (92.5%). The number of AUPP sold is 50% higher than that of AIMPP. The average healthiness index of these canteens is 56.8 (95% CI: 56.4–57.2), and 65.8% of school canteens (95% CI: 63.8–67.7) offer a greater variety of AUPP than AIMPP. Stratified analysis revealed that only the South macro-region showed a relative advantage in the availability of AIMPP (0.84; 95% CI: 0.7 -- 0.9) compared to AUPP. Additionally, less than half of the canteens in this region offer, on average, a greater variety of AUPP (47.7%; 95% CI: 40.4 -- 55.1) than AIMPP. Conclusion for Article 2: These findings reveal that, overall, students in private schools in Brazil are exposed to an environment that hinders healthy food choices. School canteens in the South macro-region stand out for promoting a more favorable environment for adequate and healthy eating.