### Comments and Admiration of their body fat percentage formula

The formula to predict your body fat percentage, based on your current BMI, age, and gender:

Child Body Fat % = (1.51 x BMI) – (0.70 x Age) – (3.6 x gender) + 1.4

Adult Body Fat % = (1.20 x BMI) + (0.23 x Age) – (10.8 x gender) – 5.4

where male gender= 1, female=0.

Well, this is just one possible body fat formula. Others exist^{1} from different authors, and some are specific to different races. But this formula is OK. But you should be aware that there is considerable variation in body fat percentage at any constant Body Mass Index.

**References**

- Jackson AS, Stanforth PR, Gagnon J, et al. The effect of sex, age and race on estimating percentage body fat from body mass index: the Heritage Family Study. Int J Obes Relat Metab Disord, Jun 2002;26(6):789-96

There is a problem with this formula, and others like it. They are linear.

But Body fat percentage has a curved distribution relative to body mass index, not linear.