Does My Scale Make Me Look Fat?

While I have to track my bodily functions to make sure I stay on top of my hydration and calories, I decided to add the daily weigh-in as an add-on habit. I use an impedance scale (BIA) to track my body composition. It occurred to me right away after surgery to weigh myself so see how much my missing colon weighed. I did it on the regular hospital scale. It only gave me weight information. In addition to the missing gizzards part of my surgery, I had not eaten for a few days previously. Altogether, I was down about 20 pounds. I did not know what that meant for my fat-to-lean body tissue ratios.

I asked the dietician how not having a colon or rectum affects body composition readings on my home bioelectrical impedance analysis (BIA) scales,

First, how does BIA work: This scale sends a low-level electrical current through your body and measures resistance (impedance). The current travels differently through various tissues - muscle and water conduct electricity well, while fat and bone resist it more. The device uses algorithms based on population averages to estimate body composition.

I am out of the bell curve. The algorithms assume certain organ proportions that no longer apply in my case.

The Impact of missing colon/rectum: Reduced total body water: the colon and rectum normally contain fluid and electrolytes that contribute to the body's electrical conductivity. I am missing all that tissue. Also, all the fluids and electrolytes. Who knew you didn't need it? Well, actually, I do. I combine huge fluid drinking efforts and IV fluid treatments to keep myself lubricated, as it were. The electrical current travels through different tissue routes when these organs are absent.

Practical effects: Fat reads higher, and lean reads lower than my actual composition.

Body fat percentage might read slightly higher than actual. I did not need to know this. It’s a built-in excuse to fudge on my diet. “Oh, the scale is off, I am really only 12%, go ahead and give me more cake.” On the other side, Muscle mass estimates could be somewhat lower. Which is an ego boost. My muscle mass is already way over the top of the bell curve; if it’s reading lower, that means I am really a hulk.

What I can do:

I don’t need an exact fix for my purposes. I use the scale consistently (same time of day, hydration status) to track trends rather than focusing on absolute values. If on Monday I was 4 pounds up, I can look at the seven-day average and see that my weight over many days is consistent. Still a hulk on average.

For a few dollars more.

If you really want granular, exact data, consider DEXA scans for more accurate measurements of body composition. If you are out of the normal range for organ content like me, inform your healthcare providers about your surgical history when interpreting body composition data, because missing several feet of body tissue will throw off your results. Not everyone fits the bell curve.

The good news is that BIA scales are still useful for tracking changes over time, even if the absolute readings aren't perfectly calibrated for your anatomy, or lack thereof.

As a side note, I want to mark an anniversary of sorts. My last surgery was three years ago this month, knock on wood. I think it’s time to set a new milestone to reference my life's journey. What should I reference going forward to mark my progress as a person with goals?

What am I reading this week?

War Master’s Gate | Adrian Tchaikovsky. I like the epic scope of this series; there is a great variety of insect-based races, such as spiders and beetles. Each race exhibits characteristics you might associate with that kind of insect. Ants are good at working together, but not innovative, for example.

My main takeaways: never trust a Spider, and words have power.