Percent body fat!

thelonghouse said:

I have recently acquired one of new fangled sets of weighing scales that
measures, amongst other things, body fat.

I am intrigued as to how it does that without making some rather
sweeping assumptions, and I think it's entirely likely that the sweeping
assumptions it's making don't really work for you or your body.

I would be inclined to disbelieve the scales and listen to (and look at)
your body directly.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

Peter Clinch said:

thelonghouse said:

I have recently acquired one of new fangled sets of weighing scales
that measures, amongst other things, body fat.

I am intrigued as to how it does that without making some rather
sweeping assumptions, and I think it's entirely likely that the
sweeping assumptions it's making don't really work for you or your
body.

I think they work by passing electric current through your body and
doing some sums based to the resistance, since fat, muscle, bone etc
have different resistances.

No idea what the accuracy of these gizmos tends to be.

Quoted message said:

I would be inclined to disbelieve the scales and listen to (and look
at) your body directly.

OTOH it could be that the scales are right but there's actually no
problem - 17% is in the normal range... and we we all need a
reasonable amount of body fat to be healthy.

thelonghouse said:

I have recently acquired one of new fangled sets of weighing scales that
measures, amongst other things, body fat. I was then quite surprised that
the results were higher than I expected.

I am a 36 yr old male height 183 cm, weight 63 kg (BMI of about 19). I
cycle approx. 50 hilly miles per day (5 days a week). So although I don't
do much upper body exercise I certainly don't have any excess fat. However,
according to the scales my body fat is nearly 17%. Certainingly in the
normal range but much higher than I was expecting! I had a go with some of
the on-line calculators using height, weight, waist and obtained values
from -2% (?) to 10%. The 10% mark is roughly what I was expecting.

-2 is funny.

Quoted message said:

My diet is probably not as good as it could be. To be honest I have enough
difficulty taking in sufficient calories for my daily ride. So maybe diet
accounts for some of it. However, I was wondering what other cyclists
experience of these sort of devices are and what else affects the results on
these machines?

http://calorielab.com/news/2005/10/22/body-fat-measurement-in-a-nutshell/

BugBear

Paul Rudin said:

I think they work by passing electric current through your body and
doing some sums based to the resistance, since fat, muscle, bone etc
have different resistances.

Essentially, yes - muscle holds water, fat doesn't, so as far as I
understand it they work out what your muscle mass is based on your
conductivity, guess your bone etc mass based on lookup tables (this is
why you tell them your height, weight, sex, etc) and anything else is fat.

I find mine quite entertaining, but on a day-to-day basis it tells me
more about how hydrated I am than how much flab I'm carrying.
Yesterday I was allegedly 18% fat (and I wasn't even hungover, dunno how
it got that number), today it's down to 13%. That's actually a pretty
extreme example - usually it changes more gradually than that - but it
gives you an idea.

-dan

--
http://www.coruskate.net/

Paul Rudin said:

Peter Clinch said:

thelonghouse said:

I have recently acquired one of new fangled sets of weighing scales
that measures, amongst other things, body fat.

Quoted message said:

I am intrigued as to how it does that without making some rather
sweeping assumptions, and I think it's entirely likely that the
sweeping assumptions it's making don't really work for you or your
body.

I think they work by passing electric current through your body and
doing some sums based to the resistance, since fat, muscle, bone etc
have different resistances.

No idea what the accuracy of these gizmos tends to be.

Most just send the (very small) current up one leg, and down the
other. Cheaper ones assume that you are of average leg length, more
expensive ones allow you to enter your height and/or inside leg length
and asjust as appropriate.
Your sex also affects how fat is distributed around you body, i.e. (in
a generalisation that could get me shot) men with beer guts, women
with large thighs/backside. Again, some will allow you to specify
your sex, other assume an androgynous "average" figure.

Quoted message said:

Quoted message said:

I would be inclined to disbelieve the scales and listen to (and look
at) your body directly.

OTOH it could be that the scales are right but there's actually no
problem - 17% is in the normal range... and we we all need a
reasonable amount of body fat to be healthy.

I'd take the measurement at the same time each day for say 10 days or
so, and see how consistent it is. If it's fairly consistent, you
could then see if it drops through the season as you lose body fat.

If it gives consistent readings, and changes in line with what you see
in the mirror, you could take it as indicating "better" or "worse",
but I wouldn't attach too much weight to the absolute number it
produces.

There again, you could just look in the mirror.

hth,

bookieb

Daniel Barlow said:

That's actually a pretty
extreme example - usually it changes more gradually than that - but it
gives you an idea.

.... that they're not much use! ;-/

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

On Feb 27, 9:25 am, "thelonghouse" <[email hidden]>

Quoted message said:

However, I was wondering what other cyclists
experience of these sort of devices are and what else affects the results on
these machines?

My missus got a set of the Tanita(?) scales.....because she thinks we
have more money than sense. They have electrode plates that you stand
on and you input your age, sex and height.

They do tend to be fairly consisent within a range of 13-17% for me
(which varies with the time of year, Christmas being strangely high on
the scale). As mentioned by someone else, my hydration level can
affect the reading by a few percent.

By way of comparison, last year I underwent some physiology tests at
Brunel University as part of some research for a friend of a friend.
This included BMI and percentage fat measurement using scales and
calipers applied to my (not too generous) love handles. Their result
was about 12% so maybe the scales are not too far out. But still a
waste of money ;-)

Daniel Barlow said:

Yesterday I was allegedly 18% fat (and I wasn't even hungover, dunno how
it got that number)

Confused? Kebab/curry effects?

stevo said:

Daniel Barlow said:

Yesterday I was allegedly 18% fat (and I wasn't even hungover, dunno how
it got that number)

Confused? Kebab/curry effects?

No - getting lashed the night before will leave you dehydrated the
following day which confuses the resistance reading through the
electrodes!

Peter Clinch said:

thelonghouse said:

I have recently acquired one of new fangled sets of weighing scales that
measures, amongst other things, body fat.

I am intrigued as to how it does that without making some rather
sweeping assumptions, and I think it's entirely likely that the sweeping
assumptions it's making don't really work for you or your body.

I would be inclined to disbelieve the scales and listen to (and look at)
your body directly.

There is an alternative method of accurately measuring % body fat.

It's called dissection.

On Feb 27, 5:25 am, "thelonghouse" <[email hidden]>

Quoted message said:

I have recently acquired one of new fangled sets of weighing scales that
measures, amongst other things, body fat. I was then quite surprised that
the results were higher than I expected.

I am a 36 yr old male height 183 cm, weight 63 kg (BMI of about 19). I
cycle approx. 50 hilly miles per day (5 days a week). So although I don't
do much upper body exercise I certainly don't have any excess fat. However,
according to the scales my body fat is nearly 17%. Certainingly in the
normal range but much higher than I was expecting! I had a go with some of
the on-line calculators using height, weight, waist and obtained values
from -2% (?) to 10%. The 10% mark is roughly what I was expecting.

My diet is probably not as good as it could be. To be honest I have enough
difficulty taking in sufficient calories for my daily ride. So maybe diet
accounts for some of it. However, I was wondering what other cyclists
experience of these sort of devices are and what else affects the results on
these machines?

Thanks,

Gordon

The fitter you are, the more meaningless those machines become as
their results are based on you being of average build and fitness. I'm
6'5" and over 15.5 stone (bmi 26.1) and according to my last health
check I have a body fat of 9%, but according to a friends set of
scales 19% body fat. I'll be surprised you're even at 10% body fat, if
you want to get a better and more accurate result go see a health
professional.

"thelonghouse" <[email hidden]>typed

Quoted message said:

I have recently acquired one of new fangled sets of weighing scales that
measures, amongst other things, body fat. I was then quite surprised that
the results were higher than I expected.

Quoted message said:

I am a 36 yr old male height 183 cm, weight 63 kg (BMI of about 19). I
cycle approx. 50 hilly miles per day (5 days a week). So although I don't
do much upper body exercise I certainly don't have any excess fat.
However,
according to the scales my body fat is nearly 17%. Certainingly in the
normal range but much higher than I was expecting! I had a go with some of
the on-line calculators using height, weight, waist and obtained values
from -2% (?) to 10%. The 10% mark is roughly what I was expecting.

Quoted message said:

My diet is probably not as good as it could be. To be honest I have enough
difficulty taking in sufficient calories for my daily ride. So maybe diet
accounts for some of it. However, I was wondering what other cyclists
experience of these sort of devices are and what else affects the
results on
these machines?

Quoted message said:

Thanks,

Quoted message said:

Gordon

You're obviously a skinny chap.

You've bought a gadget designed to feed neurosis and line the pockets of
those who market them.

Poor thing!

If your trousers get tight around the waist, you are gaining body fat,
if they get looser you are losing it. You knew that anyway, but
commonsense is no substitue for falling into a salesman's trap.

A decent tape measure, applied consistently, will probably give you
useful information.

The rest is hype.

--
Helen D. Vecht: [email hidden]
Edgware.

Paul Rudin said:

Peter Clinch <[email hidden]> writes:

Quoted message said:

Quoted message said:

thelonghouse said:

I have recently acquired one of new fangled sets of weighing scales
that measures, amongst other things, body fat.

I am intrigued as to how it does that without making some rather
sweeping assumptions, and I think it's entirely likely that the
sweeping assumptions it's making don't really work for you or your
body.

Quoted message said:

I think they work by passing electric current through your body and
doing some sums based to the resistance, since fat, muscle, bone etc
have different resistances.

Dry your feet and lose fat :-)

--
Chris Malcolm [email hidden] DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
[http://www.dai.ed.ac.uk/homes/cam/]

Chris Malcolm said:

Paul Rudin <[email hidden]> wrote:

Quoted message said:

Quoted message said:

I think they work by passing electric current through your body and
doing some sums based to the resistance, since fat, muscle, bone etc
have different resistances.

Dry your feet and lose fat :-)

AIUI they use a four point measurement, which means that the scales
ignore the contact resistance between your feet and the scales.

Martin.

bugbear directed us to:

Quoted message said:

http://calorielab.com/news/2005/10/22/body-fat-measurement-in-a-nutshell/

I'm curious about the woman sat in a giant urinal 2/3 of the way down
the page. Or is it a tiny woman in a standard urinal?

--
Danny Colyer <URL:http://www.colyer.plus.com/danny/>
Reply address is valid, but that on my website is checked more often
"He who dares not offend cannot be honest." - Thomas Paine

"thelonghouse" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

I have recently acquired one of new fangled sets of weighing scales that
measures, amongst other things, body fat. I was then quite surprised that
the results were higher than I expected.

I am a 36 yr old male height 183 cm, weight 63 kg (BMI of about 19).

I have a BMI of 32 which makes me obese. That 8 year old lad who has been
on the news (http://news.bbc.co.uk/1/hi/health/6402113.stm) is 14 stone and
will also be obese if he's the same height or shorter than me (quite
likely).

The difference is I can ride a bike up and down hills for 2 hours without
much trouble, whereas he can only do it for 10 minutes before it makes him
ill.

I conclude these body fat/ratios do not necessarily reflect how fit and able
you are!

--
peter

Cheap train tickets database
http://www.petereverett.co.uk/tickets/

Email sent to this address is generally deleted upon arrival
Visit website if you want to contact me

naked_draughtsman said:

I have a BMI of 32 which makes me obese. That 8 year old lad who has been
on the news (http://news.bbc.co.uk/1/hi/health/6402113.stm) is 14 stone and
will also be obese if he's the same height or shorter than me (quite
likely).

The difference is I can ride a bike up and down hills for 2 hours without
much trouble, whereas he can only do it for 10 minutes before it makes him
ill.

I conclude these body fat/ratios do not necessarily reflect how fit and able
you are!

Except that BMI is calculated on height and mass, and has nothing to do
with body fat ratio.

Your BMI may well be the same as that kid (I CBA to estimate what his
might really be), but that would in no way suggest that his body fat
ratio is the same as yours.

--
Danny Colyer <URL:http://www.colyer.plus.com/danny/>
Reply address is valid, but that on my website is checked more often
"He who dares not offend cannot be honest." - Thomas Paine

"thelonghouse" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

I have recently acquired one of new fangled sets of weighing scales that
measures, amongst other things, body fat. I was then quite surprised that
the results were higher than I expected.

I am a 36 yr old male height 183 cm, weight 63 kg (BMI of about 19). I
cycle approx. 50 hilly miles per day (5 days a week). So although I don't
do much upper body exercise I certainly don't have any excess fat. However,
according to the scales my body fat is nearly 17%. Certainingly in the
normal range but much higher than I was expecting! I had a go with some of
the on-line calculators using height, weight, waist and obtained values
from -2% (?) to 10%. The 10% mark is roughly what I was expecting.

My diet is probably not as good as it could be. To be honest I have enough
difficulty taking in sufficient calories for my daily ride. So maybe diet
accounts for some of it. However, I was wondering what other cyclists
experience of these sort of devices are and what else affects the results on
these machines?

Thanks,

Gordon

The "in" official NHS support cry for Diabetics this year is " Waistline!"

There is (apparently) a simple and direct correlation between waist
measurement and body fat!

In simplest terms if you're a bloke over 38 " waist you have big problems even
if your total weight says otherwise!

If I make 38/39" by the end of March and then for the rest of the warm season
( till about mid November) I am very happy! -- but it is hard work -- thank
goodness for my velo! When I get back from my annual tour I am at peak fitness
and it deteriorates slowly till Christmas -- January/February is always a
mentally traumatic month for me -- it is not the cold and wet so much-- I
don't like high winds!!!!!

--
Trevor A Panther
In South Yorkshire,
England, United Kingdom.
www.tapan.pwp.blueyonder.co.uk

Danny Colyer said:

bugbear directed us to:

Quoted message said:

http://calorielab.com/news/2005/10/22/body-fat-measurement-in-a-nutshell/

I'm curious about the woman sat in a giant urinal 2/3 of the way down
the page. Or is it a tiny woman in a standard urinal?

Seems to be a more common sort of fetish than first though.

http://www.bodpod.com/images/home_side_70q.jpg