Fat Mass Index (FMI) as a Trustworthy Overweight and Obesity Marker in Mexican Pediatric Population

Abstract

Predictive formulas to estimate body composition in children have been explored for some time, to this date, the most accurate obesity diagnostic tool is to determine fat mass. The aim of this study is to establish cutoff points that allow for a precise interpretation of nutritional status using the Fat Mass Index (FMI) in a Mexican pediatric population. A literature review using PubMed and Cochrane databases was made, searching for research articles on childhood obesity that compared BMI, FM percentage, and FMI, as well as those proposing diagnostic cutoff points. Mathematic formulas and linear regressions were then used to make a proposal on accurate cutoff points for this population. Our findings show that FM percentage is less precise than BMI and FMI in diagnosing obesity, and FMI seems to be a more complete tool for assessment as it differentiates fat and muscle mass of the total body weight. Both BMI and FMI should be considered when clinical evaluations regarding weight, with BMI complementing FMI by establishing fat-free mass. Our proposed cutoff points need to be validated in this population.

Effects of Breastfeeding on Maternal Body Composition in Moroccan Lactating Women during Twelve Months after Birth Using Stable Isotopic Dilution Technique

“…The FM% also showed an important limit particularly in the case of monitoring the change of the fat mass proportion, which is due to its direct association to the fat free mass compartment. However, FMI seems to be a more realistic index to assess and monitor excess of fat because of its independence from the fat free mass compartment and takes in a count the height [ 15 ].…”

“…But several studies confirmed its limitations to determine objectively the extent of obesity in societies [ 11 ]. In addition, it is still a controversy about the ideal indicator to measure overweight or obesity; as many scientists recommend fat mass percentage (FM%) against other authors who have raised its inefficiency as an indicator to determine overweight and obesity, because of its association to the fat free mass compartment variation and does not take account of individual’s size [ 12 , 13 , 14 , 15 ]. However, fat mass index (FMI) seems to be more interesting among the community of scientists and to be more relevant to assess excess of fat and its associations to illness [ 11 , 15 , 16 ].…”

The association between fetal growth and neonatal adiposity in urban South African infants

“…Fat mass index (FMI) was identified as the most reliable index for estimating neonatal adiposity 22 and was calculated from these estimates as previously described 12 . Due to the varying applicability of exponents in body composition indices demonstrated across populations, 23 the specific index used (kg/m 3 ) was confirmed to best describe the relationship between weight and length in the study population by regressing fat mass on length (data in natural logarithms; regression power exponent: 2.8 ± 0.6 [SE]).…”

“…Fat mass index (FMI) was identified as the most reliable index for estimating neonatal adiposity 22 and was calculated from these estimates as previously described. 12 Due to the varying applicability of with fetal growth and neonatal size and adiposity.…”

Determinants of Infant Adiposity across the First 6 Months of Life: Evidence from the Baby-bod study

“…FMI is recommended as a more appropriate approach that allows independent evaluation of FM relative to body size (height) [ 23 ]. In addition, recent research has demonstrated that FMI is a more reliable index than %FM when assessing neonatal adiposity [ 48 ]. In contrast, some studies [ 26 , 47 ] have suggested that an appropriate index should adjust the originator of the risk (FM) for a variable that is bearing the risk (FFM), thus recommending the index of FM/FFM p ; however, to the best to our knowledge, only one study [ 26 ] used FM/FFM p to identify maternal predictors of infant adiposity at birth.…”