Review of Body Fat/Activity Assessment Tools

Azdak

I came across this review when I was researching some other topics and I thought some people might find it useful.

It reviews different methods for assessing body fat and calorie expenditure during activity. As you will see, it's hard to say there is one "gold standard" that is both universally accurate and readily available/affordable.

My personal experience after 25 years in this field is that there is so much variability among individuals that it is a mistake to expect precision when looking at weight, body fat, etc. There is also no substitute for the experience of a qualified and ethical fitness professional when it comes to assessing a person's fitness needs and progress.

http://www.dshs.state.tx.us/diabetes/PDF/PA Resource Guide Adult 08.pdf

cp005e

Thanks for the link. This is very timely for me because I had a very frustrating experience just today trying to get a body composition test (using calipers) done at my YMCA. I had the same test done last year, but it was a different person doing it and I feel like last year's tester was much more experienced and diligent than the guy I had this year. It was frustrating because I am positive that the guy did the calculations incorrectly - my percentage from one of the formulas came out higher than last year, even though all of the inputted measurements were lower. So I had to go online to try and find out what the correct formula was and do the math myself.

They took 7 measurements, and then used two formulas to come up with the body fat %. Comparing last year's numbers, I believe that they use the Jackson-Pollock 3-site "B" formula (using abdomen, suprailiac, and tricep for women) and the 4-site formula (using the same 3 plus thigh). The guy doing my measurements then just averaged the 2, even though they were 8% different! (By comparison, the 2 formulas only differed by a couple of percent last year.)

Last year, the guy marked the spots he was going to measure on my body with a pen, and measured each site twice. This year, the guy only measured each spot once, AND he did it through my shirt (which seems ridiculous)!

Anyway, here are the formulas that I found online that I believe they used. It was really a pain to find the actual formulas online so I am posting them in hopes that it makes it easier for someone else. NOTE: "^2" means "squared". Also, these are the formulas for women - they are different for men.

Jackson-Pollock 3-site "A" (using tricep, suprailiac, and thigh) for women body density (Db):
Db = 1.0994921 - (0.0009929 * [sum of 3 sites in mm]) + (0.0000023 * [sum of 3]^2) - (0.0001392 * [age])

Jackson-Pollock 3-site "B" (using tricep, suprailiac, and abdomen) for women:
Db = 1.089733 - (0.0009245 * [sum of 3]) + (0.0000025 * [sum of 3]^2) - (0.0000979 * [age])

Then both formulas convert body density (Db) to body fat percentage using this equation:
Body fat % = (4.95 / Db) - 4.5

Jackson-Pollock 4-site (using tricep, suprailiac, abdomen, and thigh) for women:
Body fat % = (0.29669 * [sum of 4]) - (0.00043 * [sum of 4]^2) + (0.02963 * [age]) + 1.4072

Keep in mind that with caliper measurements it is very important that they are done by someone who is experienced and can do them the exact same way every time.