1 Data treatment

The data analyzed in this study were derived from the baseline wave of the Brazilian Longitudinal Study of Aging (ELSI-Brazil), conducted in 2015. The original sample consisted of 9,412 participants. Following internal consistency checks of anthropometric data, 649 observations with missing or implausible weight and/or height values were identified and excluded, resulting in a final analytic sample of 8,763 individuals. This data-cleaning step was performed to ensure the quality of derived indicators, such as body mass index (BMI), and the reliability of subsequent analyses.

Figures A through D present the anthropometric and functional characterization of the participants, as well as their distribution across age groups. Figure A displays the distribution of body mass index (BMI), with a concentration observed between 23 and 30 kg/m². Figure B shows the average walking speed (in meters per second) stratified by age group, revealing a progressive decline among older participants. Figure C examines the correlation between age and walking speed, demonstrating a significant negative association consistent with the expected functional decline during aging. Finally, Figure D depicts the distribution of BMI across age groups, indicating variations in body composition among the analyzed strata.