# Effect of hardware on Body fat scale?



## BuenosAires (Apr 3, 2004)

Does anyone know if hardware in the body has an effect on the accuracy of body fat scales? I have 2 plates and 20 screws in my left leg. The measurement on my scale seems a bit high.


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## OldEndicottHiway (Jul 16, 2007)

I really don't have a clue. The plates/screws are titanium I assume. If you're really set on knowing, talk to the surgeon to get an accurate description of the hardware placed (they will have each piece, its name, exact size and which medical company fabricated it in your medical records. This info is found in the surgeon's "Procedure Reports" or "Report of Operation" and is very easy for his/her staff to look up). 

Then you'd have to contact the company that made the hardware and see if they have weights on the stuff. 

Then, I would think you could contact the manufacturer of the body fat scale, and see if they could tell you how to adjust the readings accordingly by some simple math. Perhaps getting their opinion as to if it really makes that big of a difference would be the first step.

Seems like a lot of work/research though for probably not a whole lot of variable in your readings. Tell you what I'll do though, when I run into one of the surgeons at work I'll ask them about this. This won't be for three or four weeks as I am on vacation starting Monday.

I'm pretty much just throwing out some wild guesses here, so in the meantime, maybe someone on these forums with some real knowledge about it will see your post and respond. 

Sorry about all the obvious surgery you've gone through, and I hope you've recovered well.


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## Kerry Irons (Feb 25, 2002)

*Moot point*



BuenosAires said:


> Does anyone know if hardware in the body has an effect on the accuracy of body fat scales? I have 2 plates and 20 screws in my left leg. The measurement on my scale seems a bit high.


Body fat scales are not accurate in the first place, so your internal hardware can hardly be a deleterious factor. If (and it's a pretty big IF) your degree of hydration remains pretty constant and you get on the scale at the same time each day, and your feet are the same degree of "dryness" etc. etc. etc. then you can use the BF scales for seeing whether your BF is going up or down. You cannot, however, rely on the scales to tell you what your BF is. If the scale gives you the right answer, it is by chance.


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## hooper (Jul 22, 2006)

The mirror is really accurate. look, see more definition, fat going down. Another good sign of fat loss is feeling just not quite satisfied with your intake of food. Hunger = fat leaving the body. with those two measurements you should never need to get bogged down with a cheap, crappy useless scale that you wasted money on. Oh the final test for bodyfat decline will be ... Looser fitting clothing.


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## estone2 (Sep 25, 2005)

I dunno about the looser fitting clothing. When I lose body fat, I gain muscle. My legs are much larger than they were before I started riding. It's not fat. Keep muscle growth in mind.


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## rush01 (Aug 29, 2007)

I would guess that it would make a difference. If I understand those scales correctly they send a small electrical pulse from one side and measure how long it takes to get to the other. So anything that changes that will affect the measurement.

These scales are notioriously innaccurate. I had one show a 34% body fat and when I was measured wih calipers I showed 19%. The calipers are typically accurate.

Rush Carter
CS West Bikes


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## Kerry Irons (Feb 25, 2002)

*Misunderstanding*



rush01 said:


> If I understand those scales correctly they send a small electrical pulse from one side and measure how long it takes to get to the other.


Well, you don't  They measure impedance (resistance to current flow). There is no pulsing, and no time dependence. It's like holding a sensitive ohm meter in your hands, but they use your legs because there's not a bunch of internal organs and lungs in between. Still, degree of hydration, amount of muscle mass, etc. will throw the scales off.


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## Mark McM (Jun 18, 2005)

*Conduction: Fat vs. water (vs. metal)*



BuenosAires said:


> Does anyone know if hardware in the body has an effect on the accuracy of body fat scales? I have 2 plates and 20 screws in my left leg. The measurement on my scale seems a bit high.


As Kerry reported, these scales measure the resistance of the body to an electrical current, and are highly influenced by factors like hydration level. The plates and screws would only have an affect if they were directly in the path of the current (they might be), but they would only have a _significant_ affect if they were along a significant distance of the current path (odds are they aren't). Given the wild variability of these devices, the affect of the plates and screws is probably in the noise.

Besides which: The basic concept of electrical current fat measurements is that tissues with a high water content (like muscle) conduct current much better than tissues with a high adipose (fat) content. So the better your body is at conducting current, the lower the percentage of fat. Since the plates and screws are electical conductors, then if anything, they would cause the measurement of fat percent to be too low, not too high.


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