my wife checked her body fat % using the zone calculator, it came up with 18% body fat.

When we used 4 other type formulas we came up with 33%, 30.4%, 28.3% and 26.9%.

we used the Deurenberg 1&2 formula, the Gallagher formula, and the Jackson Pollock formula.

Deurenberg formula 1 (1.20 x BMI) + (0.23 x Age) - (10.8 x Gender) - 5.4 her results 33.0%

Deurenberg formula 2 (1.29 x BMI) + (0.2 x Age) - (11.3 x Gender) - 8 her results 30.4%

Gallagher formula (1.46 x BMI) + (0.14 x Age) - (11.6 x Gender) - 10 her results 28.3%

Jackson Pollock formula (1.61 x BMI) + (0.13 x Age) - (12.2 x Gender) - 13.9 her results 26.9%

Gender 1 for male 0 for female

I have 3 questions, why the difference between the zone and the others?

What is the Zone formula?

Which one is the correct formula




Bob

As you have experienced there are numerous formulas to determine % body fat and all offer varying results. Methods such as hydrostatic weighing and DEXA scanning are the accepted and most accurate methods.

"The Zone" Appendix B; tables used to determine body fat percentage were based on Dr. Michael Eades book, "Thin So Fast." The table is based on a formula, not observation. You may find Dr. Eades bibliography to Chapter 4 to be of interest. He cites the work of
Penrose, K.W.et. al."generalized body composition prediction equation for men using simple measurement techniques" Medicine and Science in Sports and Exercise" 17, no. 2 (1985) Also the work of Fisher, A. Garth, "The Complete Book of Physical Fitness" Salt Lake City; Brigham University Press, 1979 We hope you find this helpful.

Can you please provide the actual formula that the zone website uses to calculate body fat percentage?

[quote]
Posted By jaffney on 15 Apr 2013 09:50 AM
Can you please provide the actual formula that the zone website uses to calculate body fat percentage?
[/quote]

hai jaffney !

When you calculate body fat percentage you want to know about body fat chart .

Classification Women Men
Essential Fat 10-12% 2-4%
Athletes 14-20% 6-13%
Fitness 21-24% 14-17%
Acceptable 25-31% 18-25%
Obese 32% plus 25% plus

.

[quote]
Posted By jaffney on 15 Apr 2013 09:50 AM
Can you please provide the actual formula that the zone website uses to calculate body fat percentage?
[/quote]



Jaffney

To determine your daily protein requirement multiply your LBM (???) times the appropriate activity level factor. The activity factors, which represent grams of protein per pound of LBM, are Sedentary 0.5, Light 0.6, Moderate 0.7, Active 0.8, Very Active 0.9, Elite 1 (refer to specific descriptions of each level in the calc. on this site).

To determine your block requirement divide your protein requirement by 7, rounding up for any fraction of a block.

Off The Charts

If weight is slightly outside the parameters of our on-line Body Fat Calculator (300 pounds is the limit, if I’m not mistaken). When this is the case, Dr. Sears recommends to consider yourself 50% body fat and 50% LBM (divide your total weight by 2), then calculate by hand. The formula to determine your daily protein requirement is to multiply your LBM times your activity factor. Then divide this by 7 to get the block amount (there are 7 grams protein per block). Your activity factor would be at least Active (.8) determined by your aerobic activity and also because carrying around the extra weight is like strength training 24/7. This puts you at 18 blocks a day and your husband at 21 blocks. As you lose weight and your measurements are accepted by the calculator your block requirements will lessen.