bioelectrical impedance analysis

Accurate Body Fat Measurements and Being Trans

As of tomorrow, I have 5 months until my top surgery. In anticipation of that event, I wanted to bulk up some more and lose some body fat. I wanted to get an idea of where I am now, and after a few months, I’d like to take another measurement to see if I’ve made any progress.

I set up an appointment at Student Health Services for a body composition analysis. Basically, you stand on a scale that has two electrodes (one for each foot), and a current is passed through the body. The resistance is measured. Fat has a higher resistance than other components of the body. Theoretically, you can calculate body fat percentage using this measurement.

I showed up expecting to meet the assistant director of health education since that was who I had been in contact with to set up the appointment. Instead, a student health advocate introduced himself to me when I arrived. He gave me a piece of paper to fill out. It asked for my name, height, sex, and age.

At this point, I had to explain that I was transgender and didn’t know if I should write down male or female since it asked for sex. I don’t know the exact factors that go into what affects measurements. Luckily, the SHA was totally cool about it; unfortunately, he didn’t really know either since he’s basically just trained to operate the equipment. I know that female-bodied people typically have more fat than male-bodied people. And male-bodied people retain more water than female-bodied people. Both of these factors greatly influence the measurements. I don’t know to what extent testosterone alters these two factors.

So, he input my information into the machine, and it spits out a printout. It told me that I was at 35% body fat. That’s considered obese by female standards. He went over this whole spiel of resources available at UCSD (that I already knew). He also talked about calorie intake (how to gain or lose weight by eating more or less, respectively). I thought this stuff was common knowledge.

Anyway, he offered to retake the measurements with male as the input instead of female. It came out with 25.8% body fat. That’s still obese by male standards.

I’m not really sure what to make of either of these values. I’m sure they’re not very accurate in my case. I asked how the measurements from the equipment compared to hydrostatic weighing, and he had no idea what I was talking about.

Today was a bust. I have a scale in my bathroom that performs the same measurement which seems to be just as accurate even though the equipment at UCSD is probably 50-100x more expensive than my bathroom scale.

I have a lot of questions about how to accurately assess my fitness level. I can’t find any information on what standards I should be using. Should I use male standards because of my testosterone use, or should I use female standards since my body is biologically female? Should I base my caloric intake based on male or female standards? Is muscle mass the dominating factor in how many calories I should consume?

In the end, I will just have to use myself as my own experiment and see what works best for my fitness goals. I will continue to use my pictures as indication of my progress. Also, I will still be able to use my scale as an indication as long as the inaccuracy between measurements remains the same.