figuring out Body Fat % - Opinions please :D

meganjcallaghan

So I was at the drug store today and they have this handy dandy blood pressure machine you sit down at and stick your arm in the cuff....maybe you're familiar with this thing.....Anyway, they recently upgraded to one that can also weigh you and give you your BMI, calculate body fat percentage and test your vision. Of COURSE I had to play with it.

Anyhoo, in calculating BF%, you put your hands on two sensors on the machine, but before you do that part it asks you to select your activity level...you only get 3 choices. inactive, active (light to moderate exercise for an hour 3 - 5 times a week) or athlete (intense exercise 2 - 3 hours a day 5 - 6 times a week)

Now, I'm no athlete. I'd say my exercise is moderate rather than ''intense'' ...most of the time, so that would be in line with ''active''. However, between running, speedy walking and yoga/pilates, I am doing my moderate exercise 2 - 3 hours a day, 7 days a week. Thus I am stuck right in the middle of these two options.

When I selected ''Athlete" because of the frequency and amount of time I spend exercising, it told me I have 14.7% body fat. which is clearly a load of bull. When I selected ''Active'', it told me 22.8% body fat. Now....I knowwwww this thing probably isn't terribly accurate either way and of course I'd get a better analysis with calipers and whatnot....but just for poops and laughs and the sake of an estimate... do I assume the higher one is correct because the lower obviously is not, or do I split the difference because my activity level is kind of halfway between the two options?

meganjcallaghan

no opinions? in the forums? what magic is THIS? lol

Loralrose

My opinion is that if it's giving that big a difference based on "activity level," the whole thing is poop and you just can't trust it. Your BF% is what it is regardless of how active you are.... sure that might influence results a little, but 8% change is a HUGE amount. You might as well look in the mirror and guess.

JazmineYoli

Obviously the below picture isn't accurate either, but I find it helpful and pretty close. I have one of the handheld devices too. It claims you have to do it right after you wake up and before you drink, or shower. It's still just a guesstimate I think.

meganjcallaghan

haha, unfortunately the pounds of drapey excess skin make it a little difficult to guess based on looks

Mistraal1981

Obviously the below picture isn't accurate either, but I find it helpful and pretty close. I have one of the handheld devices too. It claims you have to do it right after you wake up and before you drink, or shower. It's still just a guesstimate I think.

So hard to guesstimate from those! I have the legs of the 30% girl and the upper body of the 20% girl....

Myhaloslipped

That machine is absurdly inaccurate. It told me that I have 36%BF (WTF?), and I am most definitely around 27% or so based on my measurements, the pictures posted above and the BF% test that the trainer did for me at the gym. However, that machine is fairly accurate for blood pressure.

meganjcallaghan

. However, that machine is fairly accurate for blood pressure.

that's good to know. I assumed something was wrong with that too because since I lost weight my BP has been running around 138 to 144 for systolic (yes....it's supposed to go down when you lose weight, but mine was normal to begin with and went up instead. I'm a weirdo) every time I get it checked and as recently as 3-ish weeks ago when I had to visit the donor transplant team and the doctor took it then I was up at 139/80. However, despite the fact that it was mid afternoon (when everyone's BP is usually at its highest) and I had just come off a run about 15 minutes before, it came out at 106/60 on this machine. It would be nice if that was actually accurate since maybe that means I won't have a high blood pressure problem coming my way....that would require BP medication.....that would cause diabetes.....that would take out my one remaining kidney. Here's hoping.

interesting to note, I've been doing low sodium since last august which is part of why it was so easy to drop the weight, because all those calorie dense processed food that make it so easy to pack it on are full of sodium so I've been avoiding a lot of that. In the last 2 weeks I've had more sodium (around 2300mg or sometimes a titch over) every day than I had in the previous 9 months and I feel better now than I did that whole time...and the BP has gone down with the sodium increase rather than up... if this machine is correct.

meganjcallaghan

haha...I purchased a new scale because I'm moving and won't be able to use my roommate's anymore. I got one that is supposed to be able to do the body fat % as well...not because I wanted that feature. it just happened to be the cheapest I saw....ANYhoo, according to THIS thing I have 29% body fat....like 2.5% away from what it calls ''very" high body fat. so.....now I'm 14.7%, 22.8% or 29%....depending who you ask. lol

Damundai

I found a website that may be a bit more accurate for you.. try it.

http://www.healthcentral.com/cholesterol/home-body-fat-test-2774-143.html

Lemme know what you think.

hjkgoku

What you're doing is called bioelectrical impedance and it is terribly inaccurate.

The best option is a DEXA scan, which is basically an x-ray that determines your fat free and fat mass.

Next best option is a skin fold caliper test, which can be done by a local, reputable healthcare professional.

Another option is a bodpod, which calculates fat free and fat mass by calculating the displacement of air in a sealed chamber.

But in all honesty, the most important thing is what is in front of the mirror. Body fat % is just a number. Some people look fantastic at 25% BF, while others are disappointed in themselves 18%.

meganjcallaghan

But in all honesty, the most important thing is what is in front of the mirror. Body fat % is just a number. Some people look fantastic at 25% BF, while others are disappointed in themselves 18%.

oh i can't rely on a mirror. I'll be disappointed in myself until the end of time or until i can have the skin removed...whichever comes first. how much body fat i do or don't have isn't even really visible underneath that at this point. lol

meganjcallaghan

I found a website that may be a bit more accurate for you.. try it.

http://www.healthcentral.com/cholesterol/home-body-fat-test-2774-143.html

Lemme know what you think.

this one puts me at 22%. i guess i'll go with that one then. lol

Ryderod

I agree with what hjkgoku says.
Any of those type of bodyfat sensors use bioelectrical impedance, and without getting too specific they have a fairly large margin of error. Things like water consumption, time of the month, amongst others have a large effect on the readings. At best they can be used purely for indication purposes to keep an eye on your trend, and as such are best used as close to possible as the same time of day for consistency.
The most accurate, cost effective method of measuring body fat if you feel you need the values is the skin fold caliper. Again accuracy is subject to the caliper having a good quality spring for constant pressure, and the user needs to develop a consistent method of using them.
The mirror is by far the best indicator of how well you would be progressing.