Endocrine Abstracts

Introduction: Body Mass Index (BMI) is recommended by the World Health Organization (WHO) for assessing weight due to its simplicity, reliability, and accessibility. However, as highlighted in several studies, it does not accurately reflect body fat and does not account for physiological changes in body composition that occur during different periods of life, or across sexes.

Aim: Our study aimed to determine the prevalence of underweight, overweight, and obesity according to both definitions – BMI and Percentage of Body Fat (PBF) measured by bioelectrical impedance analysis.

Methods: This is a retrospective cross-sectional study on a population of 877 Algerian volunteers who underwent a body composition assessment using multifrequency segmental direct bioelectrical impedance analysis (MSD-BIA). WHO cutoffs were used for the definition of underweight, overweight, and obesity. The comparison was made using the Pearson chi-squared test.

Results: Statistical analysis revealed numerous discrepancies between the two definitions. Indeed, 38.9% of women had a high PBF while being classified as underweight according to BMI (<18.5 kg/m²;). 48.4% and 80.6% of men and women, respectively, had a high PBF while being considered normal weight according to BMI (18.5-25 kg/m²). 12% of men and 0.7% of women classified as overweight according to BMI (25-30 kg/m²) had a normal PBF. Additionally, 1.7% of men classified as obese according to BMI (>30 kg/m²) had a low PBF.

Conclusion: Obesity has become a major health problem. The use of BMI alone appears ineffective in our population; therefore, a direct measurement of body composition is desirable to establish a correct diagnosis and act quickly to prevent potential impacts and complications, especially metabolic and cardiovascular.