Tanita BF626W scale

Martin W. Smith said:

I'm about to order a Tanita BF626W body fat scale. Any experience with this or similar models? How
accurate are body fat measurements using this method?

As I understand it, the scale only measures BF in your legs, since that is the shortest path for the
electric current. Suppose I wear one shoe and touch the opposite pad with my hand. Wouldn't that be
a more accurate measurement?

martin

--
Martin Smith email: [email hidden] Vollsveien 9 tel. : +47 6783 1188
P.O. Box 482 mob. : +47 932 48 303 1327 Lysaker, Norway

My understanding is that they are not very accurate at all, and that even the medical test using the
same principal (which I have had--you lie on a table and electric current is passed through you) is
not very accurate, only marginally better than skin calipers. I was told this by the people who used
this measurement for the research study I was in. Far more accurate is weighing underwater, which I
once tried to do and found to be a horrible experience. First they have to measure your residual air
in your lungs, then keep you underwater for what feels like forever, with you holding an empty
breath. If you are good at doing that, that is a far more accurate way to determine body fat
percentage.

My opinion is that you should skip the Tanita scale, and donate the money to medical
research. Madelaine

Martin W. Smith said:

I'm about to order a Tanita BF626W body fat scale. Any experience with this or similar models? How
accurate are body fat measurements using this method?

martin

--
Martin Smith email: [email hidden] Vollsveien 9 tel. : +47 6783 1188
P.O. Box 482 mob. : +47 932 48 303 1327 Lysaker, Norway

Martin W. Smith wrote:
:: "Martin W. Smith" wrote:
:::
::: I'm about to order a Tanita BF626W body fat scale. Any experience with this or similar models?
::: How accurate are body fat measurements using this method?
::
:: As I understand it, the scale only measures BF in your legs, since that is the shortest path for
:: the electric current. Suppose I wear one shoe and touch the opposite pad with my hand. Wouldn't
:: that be a more accurate measurement?

Well, if that is the case, the scale only meausres BF on the inner parts of your legs, since
somewhere along that route that is the shortest patch for current.

But I still think you should get one, martin.

In article said:

My understanding is that they are not very accurate at all, and that even the medical test using
the same principal (which I have had--you lie on a table and electric current is passed through
you) is not very accurate, only marginally better than skin calipers. I was told this by the people
who used this measurement for the research study I was in. Far more accurate is weighing
underwater, which I once tried to do and found to be a horrible experience. First they have to
measure your residual air in

Aside from being awkward, it's not necessarily more accurate, esp for a woman. It will assume a
given bone mass, or have a couple generics such as large frame, med, small. And then you as the rat,
er, float person needs to do the empty the lung routine - there can be great variation on that. A
pint of air extra equals an extra pound worth of displacement.

It's better than calipers, which have poor repeatability.

Quoted message said:

My opinion is that you should skip the Tanita scale, and donate the money to medical research.

Whether it's accurate or not, it's cheap, and you can measure the trend line with it. If you needed
a scale anyhow, it's not a big price premium. I found it very useful.
--
Jason O'Rourke www.jor.com

Quoted message said:

:: "Martin W. Smith" wrote:
:::
::: I'm about to order a Tanita BF626W body fat scale. Any experience with this or similar models?
::: How accurate are body fat measurements using this method?
::
:: As I understand it, the scale only measures BF in your legs, since that is the shortest path
:: for the electric current. Suppose I wear one shoe and touch the opposite pad with my hand.
:: Wouldn't that be a more accurate measurement?

They have these at my swimming center; perhaps you can talk your center into springing for one to
put by the blood pressure machine. We have two types, one that you stand on and one that you hold in
your hands. I guess they measure different parts of the body.

Although they may not be absolutely accurate, they are probably relatively accrurate from session
to session for a single person, so you could track your progress. Sort of like peak flow meters
for asthma.

[email hidden] (Jason O'Rourke) wrote in message
news:<[email hidden]>...

Quoted message said:

It's better than calipers, which have poor repeatability.

Repeatability across testers may not be good but some studies indicate that if you find an
experienced tester and stick with them then you can get reasonable results:
pponline.co.uk1025.htmOpen ↗

I'd also heard that readings from these "fat scales" are very sensitive to levels of hydration so
if you're going to use one to log a trend you need to make sure you're always hydrated to the
same level. Of course, if you're also logging your weight you'll already be concerned with
hydration levels.

AD.

adrian said:

I'd also heard that readings from these "fat scales" are very sensitive to levels of hydration so
if you're going to use one to log a trend you need to make sure you're always hydrated to the
same level. Of course, if you're also logging your weight you'll already be concerned with
hydration levels.

This is absolutely the case. I only used it in the mornings to keep it [fairly] consistent.

--
Jason O'Rourke www.jor.com

My girlfriend and I both have the Tanita TBF-622 (well, my roommate broke mine somehow, so now I use
the 2nd slot on hers). I'd say it's certainly consistant, but I don't know how accurate it
is... there is a huge difference in the reported % depending on if I choose 'athlete' or 'adult.'
I'm never really sure which one to use... I kind of consider myself both 😉. Anyway, I'd guess
it's probably +/- 2 or 3%. If you're in the normal section of the bell curve, it's probably much
more accurate, as I assume the signal it receives is standardized against empirical data. I'm
kind of on the lean (okay, skinny) end of things, so I think that throws it off a bit.

dave

"Martin W. Smith" <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

I'm about to order a Tanita BF626W body fat scale. Any experience with this or similar models? How
accurate are body fat measurements using this method?

martin

Jason O'Rourke said:

Whether it's accurate or not, it's cheap, and you can measure the trend line with it. If you
needed a scale anyhow, it's not a big price premium. I found it very useful.

That's what I think, too. The scale also has a body water measurement, but I don't know how that
works. Plotting both body fat and body water values, taken before and after workouts and taken first
thing in the morning and last thing at night, will at least give a good trend line. The question
then becomes, is it actually a trend line of body fat percentage, or just some electrical impedance
that may or may not be closely correlated with body fat percentage?

martin

--
Martin Smith email: [email hidden] Vollsveien 9 tel. : +47 6783 1188
P.O. Box 482 mob. : +47 932 48 303 1327 Lysaker, Norway

Martin W. Smith said:

The question then becomes, is it actually a trend line of body fat percentage, or just some
electrical impedance that may or may not be closely correlated with body fat percentage?

The method is valid, and it correlated with reality for me, using other methods of estimation. It's
good enough for the job of weight loss. I wouldn't use it if you were starting at below 10% and
aiming for 5. Not sure what the water level feature is on your's. Post dates mine.

--
Jason O'Rourke www.jor.com

Martin W. Smith said:

I was measured at my fitness club on a scale that uses the same impedance method. It said 19%,
which seems high, but according to a chart I saw on the web (apparently based on WHO data) 19% for
a 53 year old male is in the "excellent" range. I'm not sure I believe that and would like to drop
it a few perecentage points in any case. I'm sure 10% would be too low for me.

One convention says that BF% must trend upward with age, but I'm not convinced of it. I think it's
just a reality that most people become less active with age, and lose muscle mass. Or maybe some of
it is inevitable - testerone levels don't hold.

If you look about, there is an excel worksheet (or web pages that will do the same calcs) that will
take height, weight, waist size, etc and spit out an estimation you can use as another simple
measure. For men the fat accumulation is most concentrated there, so you can do decent relative
comparisons just by using a tape rule on your waist. For women, not so straight forward.

--
Jason O'Rourke www.jor.com

Jason O'Rourke said:

Martin W. Smith said:

The question then becomes, is it actually a trend line of body fat percentage, or just some
electrical impedance that may or may not be closely correlated with body fat percentage?

The method is valid, and it correlated with reality for me, using other methods of estimation.
It's good enough for the job of weight loss. I wouldn't use it if you were starting at below 10%
and aiming for 5. Not sure what the water level feature is on your's. Post dates mine.

I was measured at my fitness club on a scale that uses the same impedance method. It said 19%, which
seems high, but according to a chart I saw on the web (apparently based on WHO data) 19% for a 53
year old male is in the "excellent" range. I'm not sure I believe that and would like to drop it a
few perecentage points in any case. I'm sure 10% would be too low for me.

martin

--
Martin Smith email: [email hidden] Vollsveien 9 tel. : +47 6783 1188
P.O. Box 482 mob. : +47 932 48 303 1327 Lysaker, Norway

"Martin W. Smith" <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

I'm about to order a Tanita BF626W body fat scale. Any experience with this or similar models? How
accurate are body fat measurements using this method?

martin

--
Martin Smith email: [email hidden] Vollsveien 9 tel. : +47 6783 1188
P.O. Box 482 mob. : +47 932 48 303 1327 Lysaker, Norway

I have the 662 model. It has the athlete mode but not the "health monitor." I love it. The scale
part is great and it automatically gives you a body fat reading in 5 seconds. I have lost 12
pounds over the last 4 months and reduced my BF % by 6%. I'm not too sure how accurate the BF % is
in absolute terms but the percentage reduction seems about right based on the brutally honest
"stand in front of the mirror" test. It is very sensitive to hydration level. I've been biking a
lot this summer and regularly see 3% variations in body fat readings from day to day based on my
level of hydration. It is best used to track trends over weeks or months. The day to day readings
in and of themselves are not worth much. The athlete mode appears to me to be highly inaccurate. I
meet the test for "athlete" based on amount of time I work out as set forth in the instructions
that came with the scale. However, when I switch to that mode, I get a reading that is nearly what
I tested at 20 years ago when I really was an athlete. This just has to be wrong. Again, the
mirror does not lie!

STP