Body mass index and body fat percentage

a comparative analysis in the assessment of overweight and obesity

Abstract

Introduction: Obesity is a global public health problem associated with high metabolic and cardiovascular risk. Body Mass Index (BMI) is widely used for obesity screening, but it has limitations because it does not consider body composition. Body Fat Percentage (BFP) emerges as a more specific complementary metric. Objectives: To evaluate the relationship between high BFP and BMI in the classification of overweight and obesity, identifying discrepancies between the metrics and their clinical implications. Materials and Methods: This was a retrospective, descriptive and analytical cross-sectional study, carried out with secondary data from body composition assessments obtained through bioelectrical impedance analysis in an outpatient setting, specialized in nutrology. The classification followed WHO criteria for BMI and scientific literature for BFP. Results: The sample of 1,792 individuals revealed significant discrepancies between BMI and BFP in the classification of obesity. The findings reinforce the need for the complementary use of both metrics for greater diagnostic accuracy. Discussion: BMI has limitations as an isolated tool for assessing obesity, especially due to its inability to differentiate between lean mass and body fat. BMP, obtained by methods such as bioelectrical impedance, presents an alternative that allows a more detailed assessment of body composition and better stratification of metabolic risk10,12. Physiological differences between genders and age groups reinforce the need for personalized approaches. Conclusion: The combination of both tools can provide a more accurate and personalized approach, not only improving diagnostic accuracy but also facilitating the implementation of more effective therapeutic strategies, aligned with international guidelines and contemporary health demands.