Body Fat Monitor - How accurate?

MichaelK1007

I recently purchased a Omron body fat monitor from Amazon and I wonder how accurate it is. Has anyone else used this and how accurate would you say it is. I am 5’7 183lbs and the monitor had me at 16.6% but I was tested at the gym with calipers at around 14.3%.

sgt1372

Reports vary but generally they are not very accurate (as in giving you a precise measurement) or reliable (as in being able to give you a consistent reading).

I have a hand held Omrom body fat device that I purchased years ago.

The 1st reading was w/in the range of my DXA scan and hydro test but the 2rd reading was much higher than either.

So, while the device "could" give you a ressonably accurate reading, chances are that it also won't and it almost certainly won't consistently give you the same reading if you use it again under the same conditions w/in a short period of time.

Hence, the results are neither precise nor consistent and cannot be relied upon for taking a single reading, let alone establish a trend over time.

No real harm done if you're just curious what number it will give as long as you understand the the "actual" number may be quite different and don't rely on it to make decisions about your diet and/or training.

The caliper readings you are getting will probably be much more accurate and reliable in measuring your BF and determining a trend, if the person taking the measurements is experienced in using calipers and the same person takes the measurements over time.

AnvilHead

Excellent read by James Krieger about the accuracy of bioelectrical impedance analysis: https://weightology.net/the-pitfalls-of-bodyfat-measurement-part-4-bioelectrical-impedance-bia/

sijomial

AnvilHead wrote: »

Excellent read by James Krieger about the accuracy of bioelectrical impedance analysis: https://weightology.net/the-pitfalls-of-bodyfat-measurement-part-4-bioelectrical-impedance-bia/

@AnvilHead

Good article but it's an old article and the technology has moved on significantly, maybe more so in commercial grade but it's filtering down to domestic use too.

@OP

Answer to accuracy is really "it depends". Some can give a perfectly reasonable trend but are subject to individual false/weird readings. You either need to be very careful about consistency of use (not after exercise, or eating, or drinking, same time of day etc..) or just rely on lots of data points to give a trend while ignoring the random noise. A bit like how someone who weighs daily can see their weight trend despite daily fluctuations.
Some are just complete rubbish though!

The number of sensors makes a big difference too, hand AND feet sensors has a higher chance of accuracy compared to hand OR feet sensors.

I used an Omron four sensor model and it proved just as good as BodPod scans (not that BodPod is gold standard either - I got a clearly false reading from one of my scans) while being more convenient and costing far less.

TL:DR
IMHO can be OK for a long term trend, unlikely to be empirically accurate for a one off reading.

mburgess458

If you use those things at various times of the day (so various levels of hydration) you will get wildly different results... within the same day. Like numbers between 10% body fat and 20% body fat in the same day. Your "real" body fat is probably in that range but you have to know the right time of day or hydration level to get the monitor to show you the "real" body fat.