Abstract
The present study analyzed the prices of food sold in canteens of Brazilian private schools and described price-based marketing strategies, according to the NOVA food classification system. This is a mixed methods study combining a cross-sectional component and time series analysis, with data from 2,241 canteens in private elementary and secondary schools in the 26 capitals of Brazil and the Federal District, collected between June 2022 and June 2024. Price data collected for unprocessed, minimally processed, or processed foods and culinary preparations based on these foods (UMPCP), and ultra-processed foods and culinary preparations based on these foods (UpCP) sold in school canteens and from the National System of Consumer Price Indices (SNIPC), were used to create a data set containing deflated monthly prices for food and beverages sold between August 2022 and July 2024. Calculations were made for adjusted prices (R$/100 g or ml) and absolute prices (R$ per portion), and frequency of use of strategies such as combos and promotions. UMPCP showed lower adjusted price, but higher absolute price than UpCP, especially for solid foods. About 27% of the study canteens implemented pricing strategies for both food groups. Most of these strategies did not exclusively favor healthy foods, indicating that promotions and combos were used without distinction. The affordability of healthy foods is disadvantaged in school canteens when considering the price per portion, which may negatively influence students' food choices. The findings show that current prices for food sold in most canteens discourage the purchase of healthy items, but favor the purchase of unhealthy ones. These results reinforce the importance of interventions for promoting healthy foods and making them more affordable.