Reassessment of body mass indices

The accuracy of body mass indices (BMIs), such as Quetelet's index, for the definition of obesity was investigated in a large sample of healthy humans. Two hundred thirteen women and 150 men with a wide spectrum of weights, heights, and ages underwent densitometric analysis for the determination of percent body fat (%BF). %BF was then contrasted with various well-established BMIs. Although %BF was correlated with all the BMIs (r = 0.60-0.82), applying objective definitions of obesity based on BMIs or %BF by densitometry often produced conflicting results. It was also found that the 95% confidence intervals for predicting %BF by using Quetelet's index were very wide. Because of the wide variation for individuals between densitometrically determined body fat and body fat as estimated by BMIs, we conclude that BMIs should be used with caution as indicators of obesity.