The Double Burden of Malnutrition in the Brazilian Legal Amazon: Spatial Distributions and Temporal Trends (2013–2023)

Malnutrition and overweight are significant public health challenges, especially in low- and middle-income countries. In the Amazon, high rates of malnutrition and the alarming rise of obesity highlight persistent regional inequalities. Therefore, the aim of this study was to analyze spatial distributions and temporal trends of malnutrition among children under five, adults, and elderly individuals in primary healthcare services across municipalities in the Legal Amazon from 2013 to 2023. Methods: This ecological study used data from the Food and Nutritional Surveillance System (SISVAN). The analysis included the prevalences of underweight, overweight, and obesity, stratified by year, sex, and federative unit. Spatial distributions were analyzed using QGIS version 3.22, and temporal trends were assessed with Joinpoint version 4.6 and expressed as annual percentage changes (APCs) and 95% confidence intervals (95% CIs). Results: Between 2013 and 2023, SISVAN monitored 10,451,758 children under five years, 30,831,720 adults, and 4,456,650 elderly individuals in the Legal Amazon. Stunting in children under five years decreased from 20.45% to 15.30%, with a significant downward trend (APC: &minus:2.7: 95% CI: &minus:3.7: &minus:1.6). Childhood overweight exhibited a general downward trend but with notable fluctuations. Overweight in adults increased from 48.85% to 64.64%, and obesity from 17.10% to 28.49%, both showing significant upward trends. For the elderly, underweight decreased from 17.47% to 13.04%, with a downward trend until 2018, while overweight increased from 42.35% to 48.22%, with a significant upward trend until 2017. Conclusions: Despite progress in reducing childhood underweight, its prevalence in the Legal Amazon remains high compared to national averages. Significant regional disparities and rising overweight rates among adults and elderly individuals indicate a need for targeted public health strategies to address these nutritional issues.