To review the literature and select population-based studies that are representative of Brazilian capitals or Brazil as a whole to estimate the prevalence of obesity among Brazilian adults. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) were used. The search was conducted in six databases and reference lists of included studies. We included observational studies but excluded interventional studies, reviews, in vitro studies, and editorials. The study population consisted of young adults and adults (18 to 59 years old). Adolescents, infants, children, the elderly, and pregnant women were excluded. The primary outcomes were the prevalence of obesity among Brazilian adults, both men and women. The secondary outcomes were factors associated with obesity. The meta-analysis was performed using Rstudio software, version 4.1.0, by using the 'Meta' package, version 5.0-0. The search strategy identified 5634 references, of which 19 studies and 21 national surveys were included in the meta-analysis. The pooled prevalence of obesity in Brazilian adults was 20.0% (95% CI: 14.0-25.0%) while in the capitals it was 17.0% (95% CI: 16.0-19.0%). Across the regions of Brazil, the prevalence ranged from 11.0% to 17.0%, with the highest frequency in the south. Increases in obesity prevalence were observed for both sexes in almost all periods, with consistently higher rates among women in most cases. The prevalence of obesity among Brazilian adults is high, with no statistically significant differences found in the subgroup analysis.
Keywords: Brazil; adults; meta-analysis; obesity; prevalence; systematic review.