Measuring Body Composition
[Listen to an audio version of this blog here.]
Almost two years ago, I had my body composition measured utilizing a DXA scan (this is the company I used). I had it done again the other day, and the results showed slow and steady progress.
First things first, DXA stans for "Dual X-ray Absorptiometry." It's a quick and easy scan that took a total of seven minutes, and it's one of the most reliable ways to measure body composition. My results showed not only lean body mass and fat body mass, but bone density, resting metabolic rate, visceral adipose tissue, and the muscle balance in my arms and legs (my right leg is a pound lighter than my left, while my right arm is a pound heavier than my left).
DXA scans require very little preparation. I just showed up in my yoga pants and laid down on a recently disinfected table. They recommended that I arrive hydrated and without much food in my stomach. I was in and out of my scan in under ten minutes, and my results were sent to me almost immediately.
Previously in my life, when I was in the midst of my eating disorder, I was obsessed with the scale. A pound up or down could determine my mood for the day, and I weighed myself constantly. When I entered treatment, I was forced into breaking my daily scale habit, and didn't weigh myself for years. I learned to rely on how my body felt and how my clothes fit rather than a number. Later, when I started seeing my dietitian, she weighed me every other week for nearly two years and my weight barely fluctuated at all, without me trying.
At the tail end of my treatment, I went to get a standard physical and my doctor told me I was on the cusp of being overweight. I'm 5'4" and weigh roughly 150 pounds. I almost laughed outright at my doctor, who clearly didn't notice my eating disorder treatment on her chart, or notice the very obvious fact that I am not, in fact, overweight. I got my body composition taken the first time strictly out of curiosity. Pound for pound, muscle weighs more than fat, and I wanted to know how much lean mass I was carrying.
Two years ago, my body fat was 25 percent. Now, it's just over 23 percent. I gained over a pound of lean mass and lost four pounds of fat. A healthy body fat percentage varies heavily depending on who you ask, but for women my age, a healthy percentage is between 21-32 percent (find your own range here). Women can healthfully drop lower than 21 percent, but having a body fat percentage that is too low comes with a range of problems including the loss of menstruation, hormone disruption, brittle bones, chronic fatigue, vitamin deficiencies, and more. The lowest my body fat ever measured, even when I was deeply anorexic, was 13 percent, and my menstrual cycle was long gone by then.
The DXA scan also shows me progress over time. It took me nearly two years to gain 1.2 pounds of muscle, although that was never my overt intention. Since I'm very active and don't expect my composition to change much, a yearly scan is more that sufficient. If you're actively losing weight, you can safely get scanned as often as you like.
Here are a few charts from my results:
This chart shows my resting metabolic rate (RMR) as well as fat in the Android and Gynoid regions. RMR is useful to know, as it's the minimum number of calories your body needs at rest. The bottom number is from my first test, and the top is from my most recent.
The muscle balance report compares the right and left side of my body. Large imbalances (over two pounds) might be problematic. The BMC column stands for bone mineral content.
This chart shows my total fat mass as both pounds and percentages from my first and second screenings.
The chart shows my total lean mass as both pounds and percentages from my first and second screenings.
There are a tons of tools that can help measure progress in any fitness or athletic endeavor. In addition to tracking my workouts, getting yearly physicals and blood tests, and making sure I eat enough protein, body composition is a relatively simple and informative way track progress and understand weight.
P.S. Book your own scan here, read about how to change your body composition here, or check out my strength coach, Ben Beeler.
xoxo
Sarah Rose