Body fat and BMI

In this example, parallel least squares lines can be used with the logarithm of the reponse, but not the original raw response values.

Select Separate lines from the pop-up menu.

Select Natural logarithm of body fat then select Parallel lines.

ln(%Body fat) is (1.192 - 0.391) = 0.801 higher for females than for males with the same BMI.

This can be expressed more simply:

%Body fat of females is e0.810 = 2.23 times that of males with the same BMI.


Data were collected from a sample of 202 elite athletes who were in training at the Australian Institute of Sport.