Body Fat Percentage Analysis


High levels of body fat are associated with high blood pressure, Type 2 diabetes and high cholesterol according to the American College of Sports Medicine. Body composition, or body fat, is a measure of the percentage of body weight that is fat and fat-free tissue. Analysis techniques for body fat are available at fitness and research facilities. The accuracy of the technique depends on the training of the technician and certain methods of preparation.

Bioelectrical Impedence Analysis

Bioelectrical impedence analysis, or (BIA), is a commonly used method to assess body fat percentage and can be found at your local fitness facility. BIA involves passing a small electrical current through the body and measuring the opposition to electrical flow. Fat-free tissue, such as muscle, is a good conductor of electrical energy while fat tissue is not. There are hand-held BIA machines and machines similar to bathroom scales. Both machines have metal plates where you position either the hands or feet. The BIA assessment is +/- 3 percent accurate and dependent upon variables, such as hydration level, alcohol consumption and diuretic usage.

Skinfold Measurement

Skinfold measurement is a way to assess body composition by measuring fat at certain sites on the body. Tools called calipers are used to pinch nine standardized sites: the abdominals, triceps, biceps, chest, calf, under the armpit, back, hip and thigh. Some technicians use five or seven of the nine sites to assess body fat. Fat measurements are placed into a standardized equation and body composition percentages are provided. Some fitness facilities offer skinfold measurement. This test is more accurate when performed by a skilled technician. The test is +/- 3 percent accurate when done the proper way.

Hydrostatic Weighing

Hydrostatic, or underwater weighing, is a technique for measuring body fat percentage based on Archimedes’ principle of water displacement. Bone and muscle tissue are more dense than water and fat tissue is less dense. A person with more lean muscle tissue will weigh more and displace more water when placed in an underwater tank. Hydrostatic weighing is expensive and requires specialized equipment and assessment skill, therefore you’re more likely to find the service at sports research facilities. The procedure is +/- 1.5 percent accurate and dependent on accurate lung volume and air density calculations.

Bod Pod

The Bod Pod is also known as plethysmography and determines body fat by measuring air displacement. Air displacement operates similar to the principle of water displacement where lean muscle tissue displaces more air than fat tissue. Individuals are placed in a closed air chamber and air displacement is measured. Air displacement measures are calculated using a specific formula. Bod pods are available at research facilities and some elite personal training studios. This test has an error of +/- 3 percent.

Dual Energy X-Ray Absorptiometry (DEXA)

Dual energy X-ray absorptiometry, or DEXA, scan is a new technology used to assess bone mineral density and regional estimates of bone, fat and muscle tissue. Individuals lie on a table and an X-ray machine scans the body to a provide three-dimensional reading of body fatness. The DEXA machine is found in clinical settings and research facilities. This is the most accurate test to determine body composition.

About this Author

Sha Buckines is a freelance writer, fitness, and nutrition expert based in Atlanta. She has trained celebrity clients as well as business professionals since 2001. She obtained her B.S. in exercise science from Georgia State University, is American College of Sports Medicine certified and teaches group fitness classes.