T Nation

Body Fat/Composition Monitors?

Are the scale type of body fat monitors that use Bioelectrical Impedance accurate?

Here’s an example:
http://www.tanita.com./IronManScales.shtml

I guess the new week is coming early this time. This question is almost as entertaining as 140 lbs asking how to cut.

[quote]chpga wrote:
Are the scale type of body fat monitors that use Bioelectrical Impedance accurate?

Here’s an example:
http://www.tanita.com./IronManScales.shtml[/quote]

I’ve been on some good quality ones and I think they work alright. I’m thinking about getting one also because I like to know my BF% so I can make adjustments to my diet. Where’s Prof X to tell us its all BS?

i’ve come to the conclusion that they don’t work, or at least are highly inacurate (and as such i’ve stopped using them) i based this asumsion on the fact that when i go on them they regularly say my BF% is from 1.6% to 2.5%. i am lean but that is just silly.

If they are at least consistant, but not necessarily accurate, then it would still be useful.

For example, if it gives consistant readings (even though the ultimate % is wrong), then you could at least track increases/decreases in BF.

Any opinions on consistancy of readings?

They work really well. You must buy the most expensive one, though. The less expensive ones don’t work.

They have a reputation for being useless (and CL has a reputation for sarcasm, so he may be kidding, above.)

Get yourself a pair of cheap, plastic calipers. Weighing and pinching yourself in the morning takes 5 minutes.

I have one and found it to be incredibly inaccurate. I tested a friend of mine who is a professional boxer less than a week after a fight, and it gave him a reading of over 30% body fat…mind you this guy had a six pack and was ripped. It also gave me a reading that was at least 15% too high. I would go with skin fold calipers by someone who is experienced at doing that.

Consistency is a good thing, it can measure change, but i don’t know how consistent the devices are. I know that after working out consistently and cutting out all junk food and really being dilligent about what i eat…the machine said that i went up in body fat…and when i got it done with calipers it said i went down…which to me makes more sense based off my routines and diet.

I needed a new home scale anyway, so I bought a $50 scale/BF monitor (on clearance at Sports Authority).

I got my BF measured at the gym and it was 12.9%. The new scale/BF monitor said 12.2%, so it seems in the ballpark.

For it to be anywhere near your real %, you must get one with the “athletic” option.

Obviously it’s not as good as more traditional methods, but it seems to be repeatable and could track changes.