Posts Tagged 'Bioelectrical Impedence Analysis (BIA)'

FMI possibly more useful than BMI for rapid assessment of Metabolic syndrome

metabolic syndrome

An interesting, limited study published this year observes higher Fat Mass Index (FMI) levels appear to be independently and positively associated with the presence of Metabolic syndrome (MetS) regardless of Body Mass Index (BMI) and body fat percentage (BF%). FMI appears to be a better screening tool in prediction of the presence of metabolic syndrome than BMI and percentage of body fat in men and women.¹  Please note that due to the cross-sectional design, the study itself is not exploring a causal relationship between body composition and metabolic syndrome, and is limited in that it did not include a variety of ethnic groups in the cohort.

Along with the growing popularity and proven accuracy of bioelectrical impedance analysis (BIA) technology for the measurement of body composition, BMI is still widely used for the rapid assessment of obesity, and is easily calculated. However, it cannot reflect body fat mass and body fat distribution due to the differences of age, sex and ethnic groups and obese types when BMI is used alone. Although some studies [2,3] found that high BF% was associated with increased cardiovascular risk regardless of BMI whose categorization resulted in an underestimation of subjects with cardiovascular risk factors, people with the same BMI reading may have very different body composition, which may result in people with the same BMI or percentage of body fat exposing to different metabolic conditions.  Therefore, it can be better to measure and express body composition as FMI and Fat Free Mass Index (FFMI) than either BMI or BF%.

The study showed that high FMI had significantly higher odds ratio for metabolic syndrome than the low FMI in both sexes, which was similar to one previous study⁴, in which body composition was measured by DeXA. This study also showed that high FMI level was strongly associated with the presence of MetS after adjusting BMI and BF% in both men and women, and the adjusted odds ratios of the risk of MetS were higher than that of BMI and BF.


 ¹Liu, Pengju et al. “The Utility of Fat Mass Index vs. Body Mass Index and Percentage of Body Fat in the Screening of Metabolic Syndrome.”

BMC Public Health 13 (2013): 629. PMC. Web. 1 June 2016.

 ²Zeng Q, Dong SY, Sun XN, Xie J, Cui Y. Percent body fat is a better predictor of cardiovascular risk factors than body mass index. Braz J Med Biol Res. 2012;45:591–600. doi: 10.1590/S0100-879X2012007500059.

³Cho YG, Song HJ, Kim JM, Park KH, Paek YJ, Cho JJ, Caterson I, Kang JG. The estimation of cardiovascular risk factors by body mass index and body fat percentage in Korean male adults. Metabolism. 2009;58:765–771. doi: 10.1016/j.metabol.2009.01.004.

Wang J, Rennie KL, Gu W, Li H, Yu Z, Lin X. Independent associations of body-size adjusted fat mass and fat-free mass with the metabolic syndrome in Chinese. Ann Hum Biol. 2009;36:110–121. doi: 10.1080/03014460802585079.