The Big Fat Experiment
Ever been curious about how DEXA body fat measurements compare to those from other types of body fat tests? We decided to find out by sending Elaine to get her body fat measured five different ways - all in the same morning!
Here are her results:
| Method of Testing | Body Fat % |
|---|---|
| Bioelectric Impedance Scale | 24.6% |
| Bod Pod | 22.3% |
| BodySpec DEXA Scan | 27.0% |
| Calipers, 1-site | 25.0% |
| Calipers, 3-site | 23.0% |
| Calipers, 7-site | 22.0% |
| Hydrostatic Dunk Tank | 19.8% |
What does this look like on a person? Everyone will look a little different, even at the same body fat percentage.
Elaine took these pictures that same morning when she did all the tests above. For reference, Elaine is 5’3” and 130 pounds. She works with a trainer twice a week, primarily focusing on powerlifting, and also does Pilates pretty consistently.
So what's the takeaway?
Compare apples to apples, or DEXA results to DEXA results – not DEXA results to dunk tank results!
In general, results between different types of body fat measurement methods should NOT be compared against each other and used as indicators of progress.
Some more details on specific methods:
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Throughout the course of testing thousands of people, we’ve consistently seen that dunk tanks and bod pods test lower than the DEXA by a significant margin, sometimes even as much as 10%. This is particularly common with fit individuals who tend to have denser muscles and bones than the assumed average densities used in dunk tank fat calculations.
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We’ve also seen that calipers also tend to underestimate body fat – although the difference varies by person depending on individual fat distribution. Calipers will tend to underestimate your body fat level particularly if you carry fat where calipers don’t pinch, such as in your deep gut and your hips.
The DEXA scan is the only scan that actually is able to detect the composition of your entire body, head to toe, instead of using a formula. As a result, the DEXA scan is able to offer the most accurate and precise measurement - as well as the most useful way to track your progress!
