A COMPARISON OF DIFFERENT METHODS OF MEASURING FAT MASS IN HEALTHY INDIANS WITH A WIDE BMI RANGE

Area of Science:

• Human Physiology
• Body Composition Analysis
• Anthropometry

Background:

• Bioelectrical impedance analysis (BIA) is a popular method for estimating fat mass due to its ease of use.
• Existing BIA prediction equations may be population-specific and influenced by body size distributions.
• The applicability of a BIA equation derived from low body mass index (BMI) individuals to a broader Indian population requires validation.

Purpose of the Study:

• To evaluate the accuracy of a previously developed BIA prediction equation for fat mass in a diverse group of Indian males.
• To compare BIA-derived fat mass estimates with a standard skinfold method across a wide range of BMIs.
• To identify potential limitations of the BIA equation in different BMI strata.

Main Methods:

• A cohort of 68 Indian males with BMIs ranging from 16 to 26 kg/m² participated in the study.
• Fat mass was assessed using both bioelectrical impedance analysis and a skinfold method (sum of four skinfolds).
• Data were analyzed for the entire group and stratified into four BMI categories (15.0-17.9, 18.0-20.9, 21.0-23.9, and >24.0 kg/m²).

Main Results:

• The BIA equation consistently overestimated fat mass across all BMI groups compared to the skinfold method.
• The smallest mean difference between methods was observed in the lowest BMI group (0.91 ± 2.00 kg).
• The suprailiac skinfold thickness demonstrated the most linear and significant increase with rising BMI, suggesting its utility as a single fat mass indicator.

Conclusions:

• The BIA prediction equation should be used with caution in Indian males with BMIs exceeding 21 kg/m².
• The overestimation by BIA suggests potential ethnic or body composition differences not captured by the equation.
• The suprailiac skinfold measurement appears to be a robust indicator for assessing fat mass changes across varying BMIs in this population.