A few days before Thanksgiving, I scheduled an appointment for a DEXA scan to measure my body composition. I’ve estimated my body fat percentage to be in the range of 20-22% range just based on comparisons with online pictures, but I wanted to know more definitively where I stood.
DEXA scans are considered the gold standard now for body composition and are far more accurate than bioimpedance (used in many home scales now) and caliper testing.
There is some controversy regarding the accuracy of DEXA vs the hydrostatic method (water dunking), but I liked the convenience of getting a DEXA scan.
This is a picture of what the machine looks like. You basically lay on the table and do you best to hold still, while that L-shaped wand scans over your body. It’s basically a human copy machine.
The whole process takes about 10 minutes and at the end they give you a print out which I’ll go over below.
There are two main draw backs to DEXA scans.
The first is the price. In some locations, it can cost up to $450, which is prohibitively expensive. The average price from a brief search online was in the $100 – $250 range, which I felt was still out of my price range for a test that isn’t essential. Having knowledge of body composition is helpful, but serial abdominal circumference measurements while not as accurate, if viewed through the lens of long term trends, can be just as useful.
Luckily someone on paleohacks pointed me in the direction of The Exercise and Metabolic Disease Research Laboratory in UCLA that performs DEXAs for the very affordable price of $50.
The second draw back is radiation exposure. The technology is based on using X-rays to detect how dense different parts of your body are, and using these density measurements to calculate your body composition. Here is a table comparing the amount of radiation compared to other Radiologic procedures, and as you can see the radiation exposure is pretty minimal, coming out to less than 0.5% of the exposure seen with a Chest X-ray.
It’s also been said that the amount of radiation is less than the radiation you are exposed to when flying from California to New York. Despite the low radiation dose, it’s still not a procedure I’d get more than once every couple of years.
Here are my results:
This first page provides an overview of the scan on the left with an image of my skeletal structure and of the soft tissues of my body. All the white in the soft tissue diagram represents fat! Just eyeballing it, you can see that most of the fat is located around my hips, thighs, and butt… which pretty much confirms the BJJ Cavewife’s observations.
The table on the bottom right goes over the bone mineral density (BMD) of the various parts of my body with a composite total number on the bottom (circled). My total BMD is 1.264 g/cm2. This is plotted on the multicolor graph in the top right. I’m clearly in the ‘blue’ area which is average… where as the ‘green’ area would be optimal. Looks like I have to up my intake of vitamin D.
This second page is pretty much where the money is at! The scanner itself has a scale which measured my weight as 186.8 lbs. When I measured my AM weight on my home scale that morning it was 183.8 lbs. The difference in weight is easily explained because I normally weigh myself only in my boxers, whereas on the DEXA machine I was fully clothed.
The DEXA measured my total amount of body fat at 49.39 lbs, making my body fat percentage 27.4%. This was pretty surprising to me since it was much higher than what I was expecting, but I guess that is the benefit of obtaining an objective measurement, I now know exactly how much fat I’m carrying around.
The benefit is that I also know exactly how much lean weight I have, 130 lbs, which will make calculations for my desired protein intake more accurate (although calculating my exact macro intake is one of the things I most dislike about tracking).
The table in the middle goes over my fat distribution, with 29.3% as Android fat (abdominal) and 31.6% as Gynoid fat (hips and butt)… which we already know about!
The color chart on the bottom right shows that I’m right smack dab in the yellow ‘overweight’ range.
This last page details the composition of each individual body part. The technician who went over this exam with me told me that people who are right dominant usually have about 0.5 lbs more muscle and 0.5 lbs more fat on their dominant side. So the right hand of someone who is right handed will weigh about 1 lb more than their left hand. The thing that jumped out at me most was the difference in lean mass between my right leg and my left leg of almost 1.5 lbs. This corresponds to my being right leg dominant. Looks like I’ll have to do more left legged pistols to balance things out.
The bottom part of the page goes over how much ‘visceral fat’ I have which is 0.76 lbs. The technician told me that under 3 lbs is optimal, so I’m doing well here. Visceral fat (fat surrounding the internal organs) is the bad fat and is associated with insulin resistance, diabetes, and metabolic syndrome among a host of other things.
And in case you’re wondering what 27% body fat actually looks like, these were pictures I took right after I got home.
So, the main takeaways from this are that:
- I’m fatter than I thought which sucks, but at least I now know unequivocally where I stand and how much further I have to go. If I’m able to lose 25 lbs of fat that will bring me down to 15.5% body fat which would be optimal.
- I need to increase my intake of Vitamin D to hopefully get my BMD in the optimal range.
- I need to start doing more exercises to strengthen my left leg in order to balance things out.
According to Tammy who actually works in this lab:
Please refer to your region % for total body fat, since this value includes bone mass for total body. The tissue % only contains fat & muscle, no bones. The region % is more accurate.
My Total Region % Body Fat = 26.4%
While this is slightly better… I still have quite a ways to go!
Thanks for chiming in Tammy!