Introduction: Obesity is a global epidemic affecting millions of people worldwide. Its diagnosis and treatment are crucial for the prevention of associated chronic diseases. Objectives: To assess the prevalence of obesity according to different diagnostic criteria, analyze the concordance between various diagnostic methods, and identify associated factors. Methods: Peru's Demographic and Family Health Survey (ENDES) from 2019 to 2022 was utilized. The cut-off points for defining obesity were ≥ 30 for body mass index (BMI), the ATPIII criteria for waist circumference (WC-ATPIII), and 0.56 for the waist-to-height ratio (WHtR). Concordance analyses were performed to compare diagnostic methods and regression analyses were conducted to identify associated factors. Results: The prevalence of obesity according to BMI, WC-ATPIII, and WHtR was 25.65%, 42.04%, and 46.49%, respectively. The concordance between the three criteria was evaluated through the Kappa index. The concordance between obesity by BMI and WC-ATPIII was 0.5141. The concordance between BMI and WHtR was 0.5099. Finally, the concordance between WC-ATPIII and WHtR was 0.7514. Men showed a lower prevalence of obesity compared to women. The obesity trend increased overall during the study period, with marked differences in prevalence according to the obesity measure used. Conclusions: The findings reveal differences in obesity prevalence according to the diagnostic method employed and underscore the need to consider multiple approaches to assess obesity. The results significantly affect public health and provide a foundation for future interventions and policies to combat obesity in Peru.