Which One Provide A Better Prediction On Body Fat Ratio

Body Mass Index (BMI), Skin-fold thickness and Waist Hip ratio (WHR): Which one provide a better prediction on body fat ratio?

Abstract

Body Mass Index (BMI), Skin-fold thickness and Waist Hip ratio (WHR) have linkage toward body fat ratio. However, the strength of linkage of those index were not found yet. Linkage of body fat ratio between BMI, WHR, and skin-fold thickness are investigated by gender. 40 sets of data are collected in anthropometry workshop. Linear regression-derived coefficient of determination (R2) show the correlation of body fat ratio with BMI, WHR, and skin-fold thickness. From the calculation of coefficient of determination. It found that body fat ratio had the stronger link (R2 =0.87) with skin-fold thickness

For the obesity one had no sunken waist, that would be located to mid-line point between the lowest rib and iliac crest. Hip circumference was measured the maximal protrusion of the gluteal muscles. WHR is calculated by waist circumference and hip circumferences.

BMI is calculated through mathematical formula. Weight(kg) Height(m)2

Statistical analysis were modeled by scatter diagram. Three diagrams were plotted to show relationship between BMI (in kg/m2) and body fat ratio, WHR and body fat ratio, skin-fold thickness and body fat ratio. Through comparing the coefficient of determination (R2), index had the strongest link would present a largest number.(3)

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Result

Figure 1 show coefficient of determination (R2) between skin-fold thickness and Body fat ratio is 0.62.Figure 2 show coefficient of determination (R2) between BMI and Body fat ratio is 0.33. Figure 3 show coefficient of determination (R2) between WHR and Body fat ratio is 0.01. WHR show no linkage toward body fat ratio. Skin-fold thickness had the highest R2 with body fat ratio if we ignore the gender

BMI and WHR were less correlated toward body fat ratio for Men and Woman. However, if data were separated into male and female. Skin-fold thickness would be the best index to predict men body fat ratio and BMI would be the best index to predict female body fat ratio. From the past study, It found the similar result, body fat ratio is more related to waist circumference than BMI in male, and more related to BMI than waist circumference in female. Body fat ratio had linked different index by gender.(4,5)

Further research is needed to show how to use BMI and skin-fold thickness to predict the nearest data of body fat ratio. While in this research, only the linkage was found. Also, some of research data were missing. Research in past already proved that race would be the factor affect the prediction on body fat ratio. While black man have a different fat distribution compare with white man.(6) Also, Age was a factor the prediction on body fat ratio. While data on research showed that same skin-fold thickness would present different body fat ratio by different age.(5,7) After that, body shape could affect the calculation on body fat ratio, too. Some study on athlete show that high muscle content would mislead BMI classified athlete as overweight or obese.(8,9) It also can apply to related cases, such as bodybuilders or construction