T Nation

Accurate Body Fat Scales?


#1

Quick question, I was wondering what guys felt about bodyfat scales attached to your floor scale. I wanted to know if they were accurate. Thanks


#2

My results were always 3 or 4% higher with the floor scale.


#3

one of my friends has that, and he also told me that his scale reported he was 11%, and then he went and got it precisely measured with a submersion tank, and that showed he was about 15%.

what kind of floor scale do u mean though? there are bio-electric ones that measure electrical resistance, and there are ones that you manually enter in some other info.


#4

These scales are total bullshit, especially the cheaper they get. I'm pretty sure the current scale I own doesn't really use any electrical delay signal and just bases my bodyfat% of my weight, the height I entered, and probably a BMI scale or something to figure out what my bodyfat% PROBABLY is given my height and weight.

I can see all my abs. I can see my obliques. I have a pretty good ab-thigh pose as far as leanness goes. The Scale says I'm 16%. A more expensive, glass one I've tried fluctuates between 8% and 12%. In my opinion, these body% scales are so far off on their measurements that they're worthless. You're better off using a mirror and your actual bodyweight as indicators.

Or flexed/unflexed arm measurements.
Or Calipers
Or a submersion tank. But I have know idea how those work.


#5

There are no accurate bodyfat% scales that you can buy somewhere in a store

the best thing that you can measure with ANY of those devices (that includes calipers) is progress, e.g. always measure under the same circumstances and you'll see whether you bodyfat% decreases or increases.

Any absolute number you'll see on a display has an error margin around 5%, which would be nearly half of the absolute value you want to know in the first place which means you can pretty much ignore it or roll a dice instead

submerging tanks are not more accurate either

IF you really want to know your bodyfat%, you'll have to get your body analyzed with a special machine that uses x-rays at a laboratory, some bigger better equipped hospitals have those, costs well over 1000$


#6

I use an omron handheld that seems to be reasonably accurate. The precision is within about half a percent or so either way. If you are going to use a device like this it's important to take frequent readings and track the trend rather than using a single raw reading. I used calipers as well for a while, and while the accuracy was higher, the precision (repeatability) was strongly influenced by my skill at using them, something I don't want to rely on first thing in the morning.

I use a 10% smoothed exponential moving average to track both my weight and bodyfat changes. When combined with a linear regression slope line the usability of the results is pretty high. (and my spreadsheet program does all the mathmatical heavy lifting for me)


#7

I use an Omron floor scale with attached hand-held bodyfat monitor. I think I'd be better off with calipers. The scale seems pretty accurate, but I think the bodyfat measurement is consistently 5% or so high. Like Fightinmg Scott, I am very doubtful that it does anything more than estimate based on pre-loaded values.

Even if it is sending an electrical impulse that factors into its calculation of overall bodyfot %, there is no way it is doing anything more than speculating as to % of visceral fat. At most, it is marginally helpful at showing progress.