Re: Navy Study - Calculating Body Fat - Online calculator

[Guest guest]

The formulas of the paper by Hodgdon and Beckett for Prediction of

percent body fat for U.S. in navy men and women from body

circumferences and height have been incorporated into an on-line

calculator:

http://www.he.net/~zone/prothd2.html

[Guest guest]

Hi Chris:

'Ideal BF' in what sense? Are you confusing the conventional

wisdom's view of what is 'ideal body fat' (for which as far as I know

there is no real evidence) with CR-defined ideal BF - which is based

on a considerable amount of some fairly serious evidence of extension

of maximum lifespan?

Take a look at Walford's evidence for the latter and draw your own

conclusions. Yes, I know, when applied to me these numbers seem

ridiculous too.

(But all the CR experts tell us it is the daily caloric intake,

rather than BF%, that is critical, along with optimal nutrition).

Bear in mind also that the standard error for the US Navy BF

calculation is 3.5 I believe.

Rodney.

>

and that 15% BF is truly the " ideal "

> for men.

[Guest guest]

Hi :

I was trying to distinguish between conventional wisdom 'ideals' and

CR 'ideals'. The US Navy's ideal BF% of 15% is of the conventional

wisdom type, in my opinion.

To the extent there is a CR ideal BF% for males, it is defined (IMO)

by Walford's " don't go below 6% " . That is a whole lot less than the

US Navy's 15%. And a whole lot even less than the 21% I get from

applying some other conventional wisdom methods to my case to

determine my ideal weight (using wrist circumference as well as

height in the measurement) and then using the US Navy method to

determine my BF% at that (supposedly) ideal weight.

I don't think 15% body fat (even less so, 21%) is likely to represent

CR in any real sense. If calories are genuinely restricted then the

body is going to burn off excess fat. Fifteen percent sounds like a

lot of excess to me. But given a 3.5 standard deviation, stopping at

10%, rather than 6%, might be a safer target, one would think. Of

course I am no authority on this, as you know. It might be wise,

if/when one gets down to, say, 12%, to get a proper, immersion,

measurement of BF%.

I hope this explains where I am coming from.

Rodney.

> What is the CR-defined ideal BF?

>

> Thanks

>

>

> >From: " Rodney " <perspect1111@y...>

> >Reply-

> >

> >Subject: [ ] Re: Navy Study - Calculating Body Fat -

Online

> >calculator

> >Date: Wed, 26 May 2004 11:15:16 -0000

> >

> >Hi Chris:

> >

> >'Ideal BF' in what sense? Are you confusing the conventional

> >wisdom's view of what is 'ideal body fat' (for which as far as I

know

> >there is no real evidence) with CR-defined ideal BF - which is

based

> >on a considerable amount of some fairly serious evidence of

extension

> >of maximum lifespan?

> >

> >Take a look at Walford's evidence for the latter and draw your own

> >conclusions. Yes, I know, when applied to me these numbers seem

> >ridiculous too.

> >

> >(But all the CR experts tell us it is the daily caloric intake,

> >rather than BF%, that is critical, along with optimal nutrition).

> >

> >Bear in mind also that the standard error for the US Navy BF

> >calculation is 3.5 I believe.

> >

> >Rodney.

> >

> >

> >

> >--- In , " chris " <motjuste@v...>

wrote:

> > >

> > and that 15% BF is truly the " ideal "

> > > for men.

> >

[Guest guest]

Hi :

In the WUSTL study of CR practitioners, the total BF% of the males

was reported as 6.7% +/- 4.

Rodney.

> > > What is the CR-defined ideal BF?

> > >

> > > Thanks

> > >

> > >

> > > >From: " Rodney " <perspect1111@y...>

> > > >Reply-

> > > >

> > > >Subject: [ ] Re: Navy Study - Calculating Body

Fat -

> >Online

> > > >calculator

> > > >Date: Wed, 26 May 2004 11:15:16 -0000

> > > >

> > > >Hi Chris:

> > > >

> > > >'Ideal BF' in what sense? Are you confusing the conventional

> > > >wisdom's view of what is 'ideal body fat' (for which as far as

I

> >know

> > > >there is no real evidence) with CR-defined ideal BF - which is

> >based

> > > >on a considerable amount of some fairly serious evidence of

> >extension

> > > >of maximum lifespan?

> > > >

> > > >Take a look at Walford's evidence for the latter and draw your

own

> > > >conclusions. Yes, I know, when applied to me these numbers

seem

> > > >ridiculous too.

> > > >

> > > >(But all the CR experts tell us it is the daily caloric intake,

> > > >rather than BF%, that is critical, along with optimal

nutrition).

> > > >

> > > >Bear in mind also that the standard error for the US Navy BF

> > > >calculation is 3.5 I believe.

> > > >

> > > >Rodney.

> > > >

> > > >

> > > >

> > > >--- In , " chris " <motjuste@v...>

> >wrote:

> > > > >

> > > > and that 15% BF is truly the " ideal "

> > > > > for men.

> > > >

> >

[Guest guest]

Hi Chris:

A further demoralizing aspect of the numbers you mention is what you

refer to as 'wasting'. I am not sure that that is the best term to

use. Not if JW's description of the process is accurate. JW's point

is that lean mass is lost simply because, if you weigh 25% less you

do not need as much bone mass to support yourself, nor as much muscle

to do what you need to do moving yourself around.

So, just as with astronauts in 'zero gravity', (of course it isn't

really zero gravity, but let's not get into that) because there is

much less stress on their bodies the body simply adjusts to the

amount of bone and muscle it figures it needs. Of course it doesn't

know that they will be back down on earth again later when previous

amounts of lean mass will be needed again.

I do not have good data for the amount of lean mass lost during the

transition to a CR weight. But I do have two very approximate

observation points that may be of interest. Positivedennis here gave

some data for his weight loss recently with accompanying numbers for

BF%. I also have data for my loss of weight the last few months and

BF% data based on the US Navy formula.

VERY tentatively, it looks like in the case of Positivedennis - who

was losing weight from an 'overweight' level - of the weight he lost

80% of it was fat and 20% was lean body mass. In my case, losing

weight from my 'conventional wisdom ideal weight' level, it seems to

have been only 60% fat and 40% lean body mass. (VERY APPROXIMATE).

The reason this may be demoralizing is that your 6%-body-fat-weight

will be much lower than you think, because the weight loss is not by

any means all fat.

If anyone has GOOD data for the proportions of fat and lean lost by

those transitioning to a realistic CR weight, I sure would be

interested to see it. TIA.

Rodney.

>

> Well, all right. That's more like reality. That says that

my " ideal

> weight " is 189 lbs, and that my lean body mass is 164 lbs. If I

listened to

> the BMI people I would have to have a BF% of zero before they

started

> allowing that I might be " fit " .

>

> Still, this is assuming that there wouldn't be any " wasting " effect

with CR

> (I'm currently averaging 1,500 kcal/d), and that 15% BF is truly

the " ideal "

> for men.

[Guest guest]

Hi :

Demoralized because my impression was that the author of the original

post was relieved to discover (he thought, based on the US Navy

article) that the ideal BF% was 15. It seemed he had been daunted by

the idea of having to go lower than that, or perhaps even that low.

I think my post suggests not only that to get the benefits of real CR

(as shown very clearly in the WUSTL study) means going down

eventually to below 10% (6.7% average in the WUSTL study) but in

addition to that, much of the weight lost in the process would not be

fat, which would mean total weight loss would need to be even greater

to get down to the apparently typical BF% of full-scale CR, than if

all the weight lost was fat weight.

(I am not sure I have explained that well. But hopefully you get the

gist.)

Rodney.

>

>

>

> >From: " Rodney " <perspect1111@y...>

> >Reply-

>

>

> >>A further demoralizing aspect of the numbers you mention is what

you

> >refer to as 'wasting'. I am not sure that that is the best term to

> >use. Not if JW's description of the process is accurate. JW's

point

> >is that lean mass is lost simply because, if you weigh 25% less you

> >do not need as much bone mass to support yourself, nor as much

muscle

> >to do what you need to do moving yourself around.

> >

> >So, just as with astronauts in 'zero gravity', (of course it isn't

> >really zero gravity, but let's not get into that) because there is

> >much less stress on their bodies the body simply adjusts to the

> >amount of bone and muscle it figures it needs. Of course it

doesn't

> >know that they will be back down on earth again later when previous

> >amounts of lean mass will be needed again...

> >

> >The reason this may be demoralizing is that your 6%-body-fat-weight

> >will be much lower than you think, because the weight loss is not

by

> >any means all fat.....

>

> Why is this " demoralizing? "

>

> If one has less body mass to move about, one requires less muscle.