Body Fat % used to calculate obesity

At my new workplace in Poole, Herbalife gave a free "Personal Body Analysis", a 1 minute test for body fat percentage (body fat %). At 168 pounds and 5'7.5" and 57 years I had BMI 25.9 and 29.7% body fat.

Tanita have an explanation and wall charts showing that I am classed as obese (just) based on body fat % basis. The wall chart was based Gallagher et al in 2000 according to Tanita.

Body Fat Ranges for standard adults

The wall chart was based Gallagher et al in 2000.

For males 40-59 years a healthy body fat % is 11-21%.

Tanita's Body Fat Monitors and Body Composition Monitors use Bioelectrical Impedance Analysis (BIA) to help calculate results.

LloydsPharmacy Body Composition Monitor

An amazing £5 from LloydsPharmacy. I spotted the same machine in a shop for Euro70 in Finland!

It works by bio-electrical impedance by passing an electric signal through the body when holding the unit in both hands. Fat is more resistant than muscle and other tissues in the body, thereby allowing the Hand Held Body Composition Monitor to calculate the Body Fat %.

For my age range, at 28.1% I'm in the Body Fat High category (22-28%) borderline to Very high Body Fat associated with obesity 28%+. The healthy range is 11-22% body Fat. (BMI 25.7, 11st 10lbs)

Body fat percentage

Body fat percentage is total body fat expressed as a percentage of total body weight. It is generally agreed that men with more than 25% body fat and women with more than 33% body fat are obese.^[15] Body fat percentage can be estimated from a person's BMI by the following formula:

Bodyfat% = 1.2 * BMI + 0.23 * age − 5.4 − 10.8 * gender

where gender is 0 if female and 1 if male

Crabsallover bodyfat% = 1.2 *27.4 +0.23*52-5.4-10.8*1=28.64%

Accordingly by this definition I'm obese. I need to reduce BMI to 24.3 (at 52 years), 24.1 (at 53 years), 22.5 (at 60 years) or 20.5 (at 72 years) to avoid being classified as obese.

This formula takes into account the fact that body fat percentage is 10% greater in women then in men for a given BMI. It recognizes that a person's percentage body fat increases as they age even if their weight remains constant. The results have an accuracy of 4%.^[16]