Calculating Body Fat Based on a Navy Study Bill Bailey, Ph.D., MH, ND, CNHP, CTN (Dr. Bailey can be reached at Traditional Naturopath)

This information is taken from a study by  Hodgdon, J. and Beckett, M.:  "Prediction of percent body fat for U.S. navy men and women from body circumferences and height."  Reports No. 84-29 and 84-11.  Naval Health Research Center, San Diego, Cal. 1984)  The study took into account Navy men and women and measured their physical characteristics, then tested them with water displacement tests to determine actual body fat content.  The following formulas were then developed to allow fairly accurate approximation of body fat from body measurements alone.

WOMEN: R= .85, SEE= 3.72 % fat for n=214
% Fat=495/(1.29579-.35004(log(abd1+hip-neck))+.22100(log(height)))-450

MEN: R= .90, SEE=3.52 % fat for n=602
% Fat=495/(1.0324-.19077(log(abd2-neck))+.15456(log(height)))-450

Where the circumferences, measured to the nearest .5 cm, are:

ABD1

Horizontal, at the level of minimal abdominal width

ABD2

Horizontal at the level of the navel

HIP

Largest horizontal circumference around the hips

NECK

Inferior to the larynx with the tape sloping slightly downward to the front

HEIGHT

Is measured to the nearest .5cm without shoes

The formula for these tables can also be re-stated as approximately:

Women's % Fat = -71.938 + 105.42*log10(body weight) + .4396*hips -.5086*wrist -3.997*forearm -1.3085*height -1.354*neck,

where log10 means logarithm base 10.

For example, if you weigh 132, with 37.25" hips, 6.5" wrists, 9.5" forearms, you are 5'4" tall (64"), with a 12.25" neck, the calculation is

Women's % Fat = -71.938 + 223.55 + 16.375 - 3.306 - 37.97 - 83.74 - 16.59 = 26.381.

Notes:

• Measure body weight in pounds, and circumferences in inches.

• Measure the hips at the largest protrusion of the gluteals.

• Stand with arms extended (fingers closed), measure the dominant wrist just above the hand.

• Assuming the same position above, measure the dominant forearm at the largest part.

• Measure body height without shoes.

• Measure the neck just below the Adam's apple.

This method of calculating and determining body fat is far more exact than the "standard" methods of Body Fat measurement calculators, which are only "guess-ti-mations" of your BMI (Body Mass Index.)

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