Age is the most important factor for change in body mass index and waist circumference in older people in southern Brazil.

Objectives: The aim of this study is to assess the changes in body mass index and waist circumference (WC) and their associations with sociodemographic, behavioral, and health characteristics in non-institutionalized older people in southern Brazil over a period of ≤6 y.

Methods: This is a prospective study, with interviews conducted in 2014 and in 2019 to 2020. Of the 1451 individuals from Pelotas, Brazil, aged >60 y and interviewed in 2014, 537 were reevaluated in 2019 to 2020.