Padrões espaço-temporais e sociodemográficos de agravos nutricionais e alimentares da população brasileira

Abstract

Nutritional issues, manifesting in both anthropometric and dietary terms, represent detri- mental conditions that impact the quality of life and future prospects of individuals and

populations. These issues are typically intertwined, as inadequate dietary intake—specifically of industrial products such as ultra-processed foods (UPFs)—directly affects nutritional

status. Furthermore, given their multifactorial nature, sociodemographic factors also in- fluence both aspects. Accordingly, this thesis analyzed the sociodemographic conditions

directly influencing UPF consumption among the Brazilian population aged 10 years and

older (Article 1) and identified combinations of effects that increased or decreased the con- sumption of UPFs and inadequate nutritional/metabolic profiles (INMP) among Brazilian

adults (Article 2). Furthermore, the trend, progression and factors associated with hospi- talizations for mortality caused by malnutrition were analyzed (Article 3) and the spatial

distribution of consumption of certain classes of UPF in four different age groups by Brazil- ian micro-regions (Article 4). A Bayesian hierarchical modeling approach was employed

to assess the relationship between sociodemographic predictors and ultra-processed food consumption across these micro-regions. Variable selection was initially performed using the Spike-and-Slab technique, which allows for the probabilistic inclusion of covariates in the linear predictor. Spatial structure was analyzed by comparing five models (Null, Independent, CAR, BYM, and BYM2) using the Watanabe-Akaike Information Criterion

(WAIC). The BYM2 model provided the best fit, allowing the residual variance to be de- composed into two components: a structured random effect capturing spatial dependence

between neighbors, and an unstructured effect associated with specific heterogeneity, both weighted by a mixing parameter. Analyses were conducted in the R environment, utilizing

the Rstan package for Markov Chain Monte Carlo (MCMC) sampling and R-INLA to cal- culate the spatial variance scaling factor. Chain convergence was verified via the Gelman- Rubin diagnostic and visual inspection of traceplots. This statistical framework enabled

the control of spatial autocorrelation and the precise identification of sociodemographic de- terminants of food consumption. The results indicate a high prevalence of ultra-processed

food (UPF) consumption in Brazil, particularly among the youth population (≤ 19 years

old), who surpassed adults in all categories—most notably regarding sugar-sweetened bev- erages (SSB – 66.1%) and sweets/cookies (59.1%). Spatially, a higher probability of SSB

and sweets consumption was observed in the Central-West and Southeast regions, whereas the consumption of sausages and savory snacks was concentrated along the Northeastern coast and in the South. Variable selection using the Spike-and-Slab method identified the *Bolsa Família* Program (PBF), illiteracy, and income as the primary predictors. In the final model (BYM2), micro-regions with higher PBF participation showed lower odds of SSB consumption among youth (OR = 0.86) and processed meat consumption among adults (OR = 0.93), but higher odds of savory snack consumption (OR = 1.11).

Analysis of random effects confirmed strong spatial dependence (high λ), indicating that

the geographic environment influences dietary patterns. Adults exhibited a more homoge- neous distribution of consumption across the territory, whereas high-consumption clusters

among youth were more localized, reinforcing the need for existing regionally structured

public policies aimed at controlling UPF consumption. The findings reveal a heteroge- neous distribution of ultra-processed food consumption in Brazil, with higher prevalence

among children and adolescents—particularly regarding sugar-sweetened beverages and

sweets. The impact of the *Bolsa Família* Program was twofold: it acted as a protec- tive factor regarding the consumption of beverages and sausages but was associated with

increased savory snack consumption among adults. Spatial analysis confirmed regional

patterns, with higher consumption concentrated in the South and Southeast. It is con- cluded that the socioeconomic environment and age shape dietary choices, necessitating

regionalized public policies that strengthen nutrition education and access to unprocessed foods in order to mitigate health inequalities.