The Body Mass Index BMI Should be Abandoned in Favour of the Body Shape Index BSI for Controlling Body Weight in Adults

Abstract

Otto WB Schult and Ludwig E Feinendegen

Objective: This paper aims at optimal metrology for defining healthy weights in humans using weight-height ratios.

Study Design: Normal appearing Caucasian males and females of any age and height were stochastically selected individually and grouped into cohorts of gender, different heights and ages, in order to apply rigorous statistical analyses, using the least squares method of Gauss.

Methods: 246 Caucasian males and 258 Caucasian females of “normal” appearance represent an unbiased stochastically selected cohort sufficiently large to analyse statistically individual and cohort values for Body-MassIndex, kg/m2 , and Body-Shape-Index, kg/m3 , relating to gender, height, and age.

Results: For Caucasians taller than ~1.2m the BMI is largely inferior to the BSI. In adults, the single average normal weight BSI value is 12.54 for males and 12.36 for females, with standard deviations of 1.67 and 1.95, respectively. For children smaller than ~1.2m the BMI is superior showing at normal weight an average value of ~16.0 for males and ~15.2 for females, with standard deviations of 1.70 for males and 1.66 for females. The difference between BMI and BSI applicability lies in the proportionality of body shapes changing with growth from childhood to adults.

Conclusions: The BMI is the choice for weight control only of children of <1.2m. In individuals taller than 1.7m, a single BMI value introduces serious errors and should not be used. The BSI provides a stable value with height >1.2m and should replace the BMI. - BSI and BMI cut-off values are given for severe underweight, overweight and obesity for males and females for clinical guidance and use in public health.

PDF