Pântanos alimentares e entornos comunitários: associações com o excesso de peso de crianças e adolescentes de uma cidade de grande porte do Brasil

Abstract

Introduction: Overweight and obesity in the population are among the greatest challenges to be addressed in the 21st century. The condition of living with excess weight, from childhood through adolescence, is influenced by factors related to environmental exposure, which, in turn, can lead to the early onset of non-communicable chronic diseases. Among the exposure-related factors, the food environment plays a crucial role; however, few studies have evaluated the association between food swamps in school and/or residential surroundings and excess weight in this population group. Objective: To assess the presence of food swamps in the food environment surrounding schools and residences and their association with overweight and obesity in children and adolescents. Methods: This study employed two different methodological approaches. The first was an ecological study using geolocation data on schools and food retail establishments in the city of Betim for the year 2019. Food swamps in school surroundings were identified using a 250- meter Euclidean buffer. The identification of food swamps was based on an adaptation of the model proposed by Hager et al. (2017). Environments where the sum of establishments classified as snack bars, grocery stores, and candy shops was equal to or greater than four were defined as food swamps. Normality tests were conducted for statistical analyses. Categorical variables were presented as absolute and relative frequencies, while continuous variables were described using interquartile ranges. Prevalence ratios (PR) were used for association analyses. The second approach consisted of a cross-sectional study with individual demographic and anthropometric data of children and adolescents aged 5 to 14 years, attending public municipal schools participating in the School Health Program (PSE). Weight and height measurements were taken between March and November 2019 by a trained health team. Body Mass Index (BMI) for age was calculated and classified using the WHO AnthroPlus software, with overweight defined as BMI-for-age z-score > +1. Geolocation data for both studies, including geographic coordinates, were obtained using addresses provided by the State Secretariat of Finance for food establishments, the State Secretariat of Education for schools, and the Municipal Health Secretariat for residences. QGIS 2.10.1 software was used for spatial analysis and buffer calculations. In the second study, continuous variables were described using medians, and categorical variables were reported as absolute and relative frequencies. Logistic regression models with generalized estimating equations (GEE) were employed to assess associations, expressed as odds ratios (OR). Statistical analyses were performed using STATA 17.0 software. Results: Article 1: A total of 222 operational public and private schools were evaluated. Regarding the types of food establishments within the 250-meter buffer, over 90% of school surroundings contained at least one establishment that predominantly sold mixed and ultraprocessed foods (UPFs). Among school surroundings with at least one food retailer, 78.8% included snack bars, 72.5% had restaurants, and 71.6% had bars. The prevalence of schools located in food swamps was 52.7%. In terms of associations, the prevalence of school surroundings where more than 50% of establishments primarily sold UPFs was 3.15 times higher (95% CI: 1.89–5.25) in schools located in census tracts within the highest income tertile. Article 2: A total of 2,601 students from 46 public municipal schools were evaluated, of whom 54.1% were children aged 5–9 years, and 45.9% were adolescents aged 10–14 years. The prevalence of overweight was 30.5%, with a higher rate among adolescents (33.3% vs. 28.1%, p=0.004). In the assessment of the association between food swamps and excess weight, exposure variables included the presence of food swamps in residential and school surroundings, while the outcome variable was overweight. In the simultaneous exposure model, the odds of overweight were 1.22 times higher (p=0.024) in the logistic regression model adjusted for sex, age, and income. Conclusion: There is a higher availability of establishments selling UPFs in the surroundings of the evaluated public schools, particularly those located in census tracts with higher income levels. Most schools are situated in food swamp areas, which may increase exposure to and consumption of unhealthy foods. Simultaneous exposure to unfavorable food environments in both school and residential surroundings may contribute to overweight in children and adolescents. Monitoring the food environment in school and residential areas through the identification of food swamps is a valuable tool for planning and implementing public actions aimed at preventing overweight and obesity in children and adolescents