[Content Notice for Eating Disorders]
I am a “good fatty” in the sense that I haven’t engaged in long-term unrestricted eating in many years and I make an attempt at an exercise regimen. I am a “bad fatty” in that I occasionally take breaks from my restricted eating plans, don’t engage in physical activity on a consistent basis, and am unapologetic about the fact that health can be attained even by those dubbed overweight or obese based on the BMI.
Recently, I discovered something about changes in my body composition that could be used to argue that I’m a “good fatty” — but I’m far more interested in its implications about BMI.
In 2011, I posted online about my initial hydrostatic body composition results. I remarked on how the results showed that I’d still be overweight for my height by BMI standards even if I were to reach 20% body fat. I was told that I couldn’t expect to maintain the same level of lean muscle mass if I were to lose weight. In order words, people assured me that I’d lose lean muscle mass as well as fat as I dropped pounds, meaning that BMI would still be a valid measure and that I’d still have a high fat percentage.
As these were people who seemed to know what they were talking about, I resigned myself to a high body fat percentage no matter how much weight I lost. Three years later, I’d prove them wrong.
My weight loss has been slow at best in the years between my initial body composition measurement and my more recent one; I’ve only been highly motivated for about one of the three years. I showed only an 8 pound loss — but gained about 2 pounds of lean muscle mass, meaning I’d lost 10 pounds of fat. This means that, if the pattern holds, my weight when I reach goal goal fat percentage will continue to place me at “overweight,” if not “obese,” according to the BMI chart.
If I were to reach 20% body fat, I’d weigh 161 pounds. At my height, 161 is on the upper end of “overweight” according to the BMI. 20% is a fairly athletic goal for a woman, though, and I am not an athlete. Let’s say I’m aiming for 25%. Barring any further gains in muscle mass, I’d weigh 172, placing me just short of the BMI definition of “obese.” If I were to gain more muscle mass, that goal weight would be even higher.
In order for me to not be overweight according to the BMI, I’d have to weigh 149. To get to that point, I would have to lose quite a lot of fat and probably at least some lean muscle mass. Not only would that be close to impossible to accomplish, it would likely be downright unhealthy for me unless I were to dedicate myself full-time to a very athletic lifestyle.
For kicks, I decided to use a BMI-based formula to calculate my body fat percentage. It decided that I must have 40% body fat, a full 6% higher than I actually have.
For me, it turns out that BMI is complete bullshit, even though I am not nor have I ever been an athlete. I wonder how many other large people, fat-shamed by their doctors and by society as a whole, are in similar situations. After all, naysayers aside, BMI has a rich history of being used as a tool by which doctors harm fat people.