Measuring BF% in women (what about the boobs...?)

[kedg]

I know there are myriad posts here and elsewhere about the various methods of BF% measurement, but there's one particular issue I've been trying to wrap my brain around so I thought I'd throw it out there.

I am 5' 3.5", ~135 lbs (fasted & naked in the AM), ~138 lbs on the scale at work midday or on my TANITA at night when I do my BF% measurement on it. He calipers are, from everything I've read, more accurate than such digital scales BUT I thought I'd also read a lot of places that the scales tend to underestimate BF%. Well, the caliper test at work (same trained professional every time, always same time of day, etc.) has me at around 21-22% while the TANITA has me at ~25% for roughly the same total weight. So they disagree, which I expect, but they're off in the opposite direction from what I'd expect from the assumptions above. Is it because of boobs? I can't figure out how the calipers could account for them and mine are fairly substantial (much to my chagrin in high school, somewhat less so now...): I'm a 32-34 DDD.

I am not interested that much in the exact %, just trend. HOWEVER, I thought I had a handle on where I was starting, based on the calipers, and that got thrown out of whack with the TANITA disagreeing in the opposite direction of what I'd expected. I'm trying to properly set my goals and this has confused things. I mean, I will still measure my success mostly by the mirror and the way clothes fit, but it is useful to have an objective measuring stick too.

kedg

[maggieandmommy]

I don't know what accounts for the differences, though I've heard people complain that the Tanita isn't as accurate as it could be. Since you've got a professional doing caliper measurements consistently, then I'd probably go by that and use it for your trending data.

[perrogrande007]

Originally Posted by kedg

Well, the caliper test at work (same trained professional every time, always same time of day, etc.)

This is your best choice. Ultimately the bodyfat % is less important than the skinfold total and that the variables are the same (same tester, time of day, etc.)

[Lost Dog]

My tanita always shows higher than calipers. My boobs are pretty typical.

[UConnJulie]

My Tanita always reads higher too ... and I'm in the same boat as you (34DDD) ... I do know that the formulas for calculating BF% for men and women are different, so I assume that the boob-factor is built into the equation.

[Espi]

The caliper tests invariably put me lower as the Omron, except for the 4-site skinfold which relies heavily on the abdominal fat which is the dominant one for me. That one always was near-identical with the Omron reading or sometimes even higher.

Day-to-day readings are very inaccurate but if you take the trouble to put all your data in a spreadsheet and measure each & every day, you'll find the Omron or Tanita to be very accurate because of the multiple datapoints. It might be off in the absolute sense, but it will be ON in the relative sense if you KWIM.