Do those body fat scales work ?

Just wondering.....

I don't think they are consistently accurate. I measured 11% by caliper method at my local gym. I got on 3 different scales that use that electrical impedance method to calculate fat and got the following results : 10%, 17% and 20%!

Things like BMI (Body Mass Index) and other body fat scales don't seem to be too acurate. They aren't reliable like goober pointed out.

According to Consumer Reports they are iffy at best, both on weight and body fat percentage.

I have one and it sucks. You have to plug in your height to get body fat. The taller I make myself the lower my body fat is. If it truly worked you would not need to plug in your height. The only real test is to be weighed under water. I got mine for 15 bucks at walgreens the scale part works.

I understand that the water scales are the ONLY known accurate measure for BF %.

In short, probably not. Unless the trainer at your local gym has logged hundreds of hours using skinfold calipers and was TRAINED PROPERLY, you likely got a bad job there, as well. Accurate calipers cost hundreds of $$. Skinfold measurements must be taken sequentially from 3-4 spots (subscapular (under the shoulder blade), back of the arm, just above the hip bone and back of the leg (hamstring area) are good spots) and non-repetitively, meaning if you take 2 back to back measurements from the same spot, the fat can compress and give an inaccurate measurement the second time. Phil is correct about underwater weighing (hydrodensitometry). Go the a local state U and they will likely have studies going on where you can get these things done for free. Hand-held and floor bioelectrical impedance machines are bologna. They can give you a consistent measurement but usually not an ACCURATE measurement. This method can be accurate if performed by a qualified exercise specialist or physiologist. When done properly, you are hooked up to various leads, kind of like an EKG, for more accuracy. There are also a host of prerequisites for the impedance test (urinating within 30 minutes of test, no diuretics, not during menstration for women, no caffeine for 24-48 hours,etc.). Bod Pods and DEXA scans also produce results nearly as accurate as underwater but can be expensive and they are hard to find. Just use the old fashioned method. If your clothes are fitting better, you are losing bodyfat. Sorry for being so technical, but my PhD is in clinical nutrition with a minor in sports nutrition/exercise physiology. Take it easy.

Thanks, I had a Dexa scan a couple of months ago and it cost about $70, that's why I was looking for a cheaper way to measure body fat. While I was there they also measured with a Omron scale and calipers, there was about a 3% variance in the different methods.

I'm pretty happy with my Fat scale...I bought a Tanita body fat scale. Its very consistent. Any they say its one of the best in the world. Tanita is probably the biggest name in body fat measurement. Measures to a tenth of a percent. Thats all I know. 10.2 percent body fat here....hehe

Eug said:

I'm pretty happy with my Fat scale...I bought a Tanita body fat scale. Its very consistent. Any they say its one of the best in the world. Tanita is probably the biggest name in body fat measurement. Measures to a tenth of a percent. Thats all I know. 10.2 percent body fat here....hehe

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Just because something measures to a tenth of a percent does not mean that it is accurate if the method used is not inherently accurate. The tenth of a percent is meaningless.

Actually all 3 machines I used were Tanitas (different models). I pretty much stopped using them. I use a scale for weight sometimes and do the eyeball test for flab. I measure my progress by what I am able to do physical tests of endurance or strength not what is my body fat %

Alright point taken, but still, can we agree that the Tanita scales are consistent? If we agree, then we can track changes in body fat which is just as important. And I dont think the scales are wildly off. +-5% maybe?

It doesn't matter how accurate the fat scale is - what you should do is ALWAYS using the same scale in order to see the changes on you BF. I only use the one at my gym. I read a discussion about bodyfat measurement and it looks like many people don't trust the scales.

While there may be more accurate methods for determining body composition than others- none are 100% accurate. Even hydrostatic weighing (in the water tank) and other technologically advanced methods have inaccuracies because they generate body composition percentages based on assumptions.

As far as the accuracy of bioelectrical impedance analysis scales (and hand held ones for that matter) are concerned, they really are best for generating a before-and-after body fat percentage comparison- as a couple posters have mentioned. Specifically with BIA, discrepancies in whether you consider yourself "active" or "normal" can generate a huge difference in results. As long as you are consistent with what settings you measure yourself with, then you can start to track whether you are actually changing around your body composition i.e. losing body fat, gaining muscle mass, increasing bone density, etc. Unfortunately, the only accurate method for determining body composition is actually weighing each component of your body, and you would have to be dead to separate all your fat mass from lean masses.

If you use the Tanita scale on the normal setting it will give you a slightly high bodyfat percentage. If you can use the athlete mode, it is much more accurate.

Simply try to weigh yourself at the same time every day and be well-hydrated when you do so. The readings should be fairly consistent within settings.

The Tanita scales are a good motivator. Don't take anything but the weight as gospel.

-Robert

The scale I have at home changes its body fat measurements depending on the height I input and how hydrated I am. If for some reason I'm parched and haven't been near water all day my body fat will register as several percentage points higher than usual, even though nothing has changed from the previous day.

The key is to weigh yourself consistently - at the same time every day, on an empty stomach, and with proper hydration - and to pay attention to increases and decreases instead of what the actual number is.

Kevin T said:

In short, probably not. Unless the trainer at your local gym has logged hundreds of hours using skinfold calipers and was TRAINED PROPERLY, you likely got a bad job there, as well.

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Absolutely true, Kevin. When gym members came to me for bf testing, they consistently got higher readings than from my coworker because of one simple reason, I went by the book. Sure, it's more flattering to come out lower, but it's more important to be honest with yourself. Was I more accurate than my coworker when it came to bf testing? Absolutely! Would the gym members think so? Probably not.

I have a scale that's supposed to take the body water etc. into account and it displays.

water%, weight, BF lb, BF%, muscle mass

It is consistent/precise for all measures, however maybe not accurate. Currently I have a journal and I document BF% changes every month and weight changes every week.

I use the Weight Watchers silver/grey and glass model. It was about 50$

It's great for trending for example to see if I'm retaining muscle while losing fat.

chess9 said:

If you use the Tanita scale on the normal setting it will give you a slightly high bodyfat percentage. If you can use the athlete mode, it is much more accurate.

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For you it would be accurate since you're an athlete, but for the average Joe, the athlete setting will give too low a reading.

I think the Tanita scale is good if you just want to keep track of how much your bodyfat is decreasing.

Actually measuring tape is all you need. Just measure your waist (most tapered point) and your belly (across your belly button) and keep track.

superman1 said:

For you it would be accurate since you're an athlete, but for the average Joe, the athlete setting will give too low a reading.

I think the Tanita scale is good if you just want to keep track of how much your bodyfat is decreasing.

Actually measuring tape is all you need. Just measure your waist (most tapered point) and your belly (across your belly button) and keep track.

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Yes, which is why I used the word "can".

Waist measure is good, as is the dreaded MIRROR.

-Robert