P215 - ETHNIC AND GENDER VARIATION IN BODY COMPOSITION: AN OBJECTIVE EVALUATION USING BIA

P215

ETHNIC AND GENDER VARIATION IN BODY COMPOSITION: AN OBJECTIVE EVALUATION USING BIA

M. Nishizawa^1,*, T. Nagahama¹, Y. Oshima¹, T. Miyama¹, Y. Yamada², A. Pietrobelli³, S. B. Heymsfield⁴

¹R&D Dept., TANITA, Tokyo, ²Department of Medicine and Science in Sports and Exercise, Tohoku University, Sendai, Japan, ³Gynaecology and Paediatrics, University of Verona, Verona, Italy, ⁴Metabolism & Body Composition, Pennington Biomedical Research Center, Louisiana , United States

Rationale: Body composition and body shape can differ significantly across sex and ethnicity, even when Body Mass Index (BMI) is the same. Therefore, the proportion of fat accumulation and muscle mass distribution is not uniform. Evaluation of obesity-related metabolic disorders due to lifestyle factors, or sarcopenia and frailty caused by aging or physical inactivity, cannot rely solely on BMI. In this study, we investigated sex and ethnic differences in body composition at equivalent BMI levels, and examined the potential of bioelectrical impedance analysis (BIA) for objectively assessing such differences.

Methods: We analyzed data from the following groups: 955 Asians, 418 Whites,258 African Americans, 400 Hispanics,using DXA to compare %FAT across BMI levels and assess differences in distribution.In addition, we evaluated the feasibility of objectively capturing sex- and ethnicity-related body composition differences using standing BIA(TANITA MC980) measurements with electrodes placed on both upper and lower limbs.

Results: Sex and ethnicity differences were noted in the BMI–%FAT relationship. Women consistently had higher %FAT than men at the same BMI. Ethnic differences were greater at lower BMIs, especially among young lean males, with Asians and Hispanics showing higher %FAT. These differences decreased with age and higher BMI. BIA also revealed sex-based variations in resistance-reactance ratios and impedance frequency responses, as well as ethnic differences in limb resistance distribution.

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Conclusion: Our findings highlight the limitations of BMI as a sole indicator for assessing risks related to fat accumulation and muscle weakness, given the evident sex and ethnic differences. Furthermore, BIA enabled objective evaluation of diverse body composition profiles, suggesting its potential to provide individualized assessments that are inclusive of population diversity.

Disclosure of Interest: None declared