Why You Should Measure Your Body Fat with a DEXA Body Scan

It may be expensive, but the DEXA scan is a great method to determine your body fat percentage.

Body fat percentages are often underestimated within the fitness community. Many times, this is due to inaccuracy of the testing devices, such as handheld bioelectrical impedance machines, or to the inexperience of a professional performing skinfold tests. This can be avoided by using a DEXA body scan.

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You often hear individuals claim they have 4, 5, 6 or 7 percent body fat. However, unless they are elite bodybuilders, chances are they are not walking around every day with such a low body fat percentage.

What are the various methods used to measure body fat?

Skinfold (Calipers)

The Good

  • Quite accurate when the practitioner is experienced
  • Least expensive of all the methods
  • Found at many gyms and health & wellness facilities

The Bad

  • 8 measurement sites mean more chance for error
  • Practitioner must be experienced; performing a skinfold measurement is a learned skill


The Good

  • Accurate measure of body fat percentage, with a relatively small margin of error

The Bad

  • Expensive; usually found only in large universities or some private facilities
  • Clothing and exposed body hair can skew the results if the practitioner isn't meticulous when conducting the scan
  • Can bother individuals who are claustrophobic

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Handheld Bioelectrical Impedance Machine

The Good

  • Portable
  • Fast results
  • Relatively accurate
  • Cheap compared to a DEXA or Bodpod

The Bad

  • Hydration levels, sodium intake and hormones can skew results


The Good

  • Extremely accurate
  • Calculates mass differences and body fat percentages of individual regions of the body—e.g., right arm versus left arm
  • Measures bone density levels
  • Identifies visceral body fat in the abdomen region, the most dangerous fat "region." Lower visceral fat can signify lower risk for long-term health problems
  • Image of body composition can be very eye opening for an overweight individual.

The Bad

  • Rather expensive
  • Hard to find; usually only found at large universities and some independent facilities
  • Small amount of radiation exposure (very small, but any radiation is worth noting)

Underwater Weighing

The Good

  • Accurate

The Bad

  • Can be uncomfortable and inconvenient
  • Requires specialized equipment, and practitioners who can be hard to find

Which measurement method should you choose?

From a broad perspective, my recommendation is that the DEXA scan is the best choice. You will not only receive an accurate measure of your body fat, but you will receive other information that can help you determine asymmetries and other information that can help you improve your health, fitness and performance. If you have the opportunity, get a scan before you start a training program. Then perform the scan again at the conclusion of your program to see if your training delivered the results you expected.

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