Re: Fat Loss as a Percentage of Total Weight Loss

[Guest guest]

--- In , " Rodney " <perspect1111@y...>

wrote:

> " What proportion of the weight I have

> lost over the past six months was fat? "

>

> For the reasons explained earlier in this post any number quoted

must

> be tentative. In coming to my conclusion I must try to take the

> middle of the ranges for the relevant variables.

>

> The tentative number is 80.2%. Yes, I know, that is quoted to far

too

> many (in)significant figures.

>

> But based on this, if I was starting out and wanted to use some

> number for the percentage of weight I would lose that was fat, I

> would use 80%. fwiw.

Hi All,

WUSTL CRers relative to controls " lost " 26% of their weight. How

much did you lose, Rodney?

They also had reduced their %fat by 70%.

If you reduced your weight this much and your fat % by that much in 6

months, I would be surprised.

Cheers, Al.

[Guest guest]

Hi Al:

You are right. I estimate I am about 40% of the way from where I

started, to where I want to be. I was simply reporting what

proportion of the weight I have lost so far appears to have been fat

loss (fat ~80% of weight lost, LBM ~20%).

To answer your question: So far I have lost about 7.6% of the total

weight I started with. My BF% (US Navy method) is down from 20.4% to

16.1%. For now my target BF% is 10%. But I am planning to stabilize

where I am here for a couple of months, before continuing. Funnily

enough I would prefer to continue, rather than stop here! But I am

going to stabilize here in the interests of caution.

Hope this clarifies.

Rodney.

>

> > " What proportion of the weight I have

> > lost over the past six months was fat? "

> >

> > For the reasons explained earlier in this post any number quoted

> must

> > be tentative. In coming to my conclusion I must try to take the

> > middle of the ranges for the relevant variables.

> >

> > The tentative number is 80.2%. Yes, I know, that is quoted to far

> too

> > many (in)significant figures.

> >

> > But based on this, if I was starting out and wanted to use some

> > number for the percentage of weight I would lose that was fat, I

> > would use 80%. fwiw.

>

> Hi All,

>

> WUSTL CRers relative to controls " lost " 26% of their weight. How

> much did you lose, Rodney?

>

> They also had reduced their %fat by 70%.

>

> If you reduced your weight this much and your fat % by that much in

6

> months, I would be surprised.

>

> Cheers, Al.

[Guest guest]

Hi Al:

Perhaps I should add to my previous post why it is I find it helpful

to try to get a handle on what percentage of the weight lost will be

fat.

If I know reasonably accurately what that percentage is (say ~80% of

total weight lost, perhaps), then it can be calculated quite

accurately what the ending total body weight will be at the chosen

target BF% (in my case, for now at least, that target is 10%).

But without that number it is not possible. If for example the

percentage of total weight lost that was fat was, for a number, 30%

then the ending total weight at 10% body fat would be much much lower.

Rodney.

> >

> > > " What proportion of the weight I have

> > > lost over the past six months was fat? "

> > >

> > > For the reasons explained earlier in this post any number

quoted

> > must

> > > be tentative. In coming to my conclusion I must try to take

the

> > > middle of the ranges for the relevant variables.

> > >

> > > The tentative number is 80.2%. Yes, I know, that is quoted to

far

> > too

> > > many (in)significant figures.

> > >

> > > But based on this, if I was starting out and wanted to use some

> > > number for the percentage of weight I would lose that was fat,

I

> > > would use 80%. fwiw.

> >

> > Hi All,

> >

> > WUSTL CRers relative to controls " lost " 26% of their weight. How

> > much did you lose, Rodney?

> >

> > They also had reduced their %fat by 70%.

> >

> > If you reduced your weight this much and your fat % by that much

in

> 6

> > months, I would be surprised.

> >

> > Cheers, Al.

[Guest guest]

--- In , " Rodney " <perspect1111@y...>

wrote:

> Hi Al:

>

> You are right. I estimate I am about 40% of the way from where I

> started, to where I want to be. I was simply reporting what

> proportion of the weight I have lost so far appears to have been

fat

> loss (fat ~80% of weight lost, LBM ~20%).

>

> To answer your question: So far I have lost about 7.6% of the

total

> weight I started with. My BF% (US Navy method) is down from 20.4%

to

> 16.1%. For now my target BF% is 10%. But I am planning to

stabilize

> where I am here for a couple of months, before continuing. Funnily

> enough I would prefer to continue, rather than stop here! But I am

> going to stabilize here in the interests of caution.

Hi All,

Rodney, your body fat numbers do not appear to me to be consistent

with what was the case with WUSTL CRers.

" down from 20.4% to 16.1% " is 80% of the way to 10% from 20.4%?

Cheers, Al Pater.

[Guest guest]

Hi Al:

Further clarification:

First, 16.1% is ~41% of the way from 20.4% to 10.0%. ( " I estimate I

am about 40% of the way from where I started, to where I want to

be " .) I want to be down to 10% body fat. I started at 20.4% body

fat. I am currently at 16.1%. That is 41% of the way.

Second, over the period for which these data were calculated, OF THE

TOTAL WEIGHT I HAVE LOST, 80% of that lost weight was fat mass. The

other 20% of the total weight lost during that period was lean body

mass.

The reason this proportion (the 80%) is of interest to me is that, if

that continues to be the case ....... that is if, of the total

weight I lose in coming months, the proportion of fat weight I lose

continues to be 80% of the total weight lost, then I can calculate

today that I will weigh 146.02 pounds when I reach my target BF% of

10%.

For me that is a helpful number to have in mind. Of course many

people will be more than happy to wait and see what it turns out to

be, and feel no need to know ahead of time. Which is fine,

naturally. But for those who are interested to try to calculate

ahead of time what their target weight will be at a given target BF%,

it is essential to know what proportion of the total weight lost is

going to be fat. It cannot be calculated without that number. (Of

course there is no guarantee that for me it will continue to be 80%.

But by the time I get down to 146 pounds I will be able to tell

anyone who is interested what that proportion was in my case).

Sorry I did not make myself clear. Is that better?

Rodney.

>

> > Hi Al:

> >

> > You are right. I estimate I am about 40% of the way from where I

> > started, to where I want to be. I was simply reporting what

> > proportion of the weight I have lost so far appears to have been

> fat

> > loss (fat ~80% of weight lost, LBM ~20%).

> >

> > To answer your question: So far I have lost about 7.6% of the

> total

> > weight I started with. My BF% (US Navy method) is down from

20.4%

> to

> > 16.1%. For now my target BF% is 10%. But I am planning to

> stabilize

> > where I am here for a couple of months, before continuing.

Funnily

> > enough I would prefer to continue, rather than stop here! But I

am

> > going to stabilize here in the interests of caution.

>

> Hi All,

>

> Rodney, your body fat numbers do not appear to me to be consistent

> with what was the case with WUSTL CRers.

>

> " down from 20.4% to 16.1% " is 80% of the way to 10% from 20.4%?

>

> Cheers, Al Pater.

[Guest guest]

>>>>

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

Date: Sun Jul 25, 2004 9:39 pm

Subject: Re: Fat Loss as a Percentage of Total Weight Loss

Further clarification:

[snip] OF THE TOTAL WEIGHT I HAVE LOST, 80% of that lost weight was

fat mass. The other 20% of the total weight lost during that period

was lean body mass.

>>>>

Your assumption about the amount lean body mass that you are losing

may need to be tweaked. Body fat normally has about 10% water which

is the reason why it is generally recognized that a pound of fat has

3500 calories instead of 4086 Calories (454g times 9 cal/g). Also, I

would assume that as your relative ratio of fat to muscle & bone

decreases, any weight loss will also have a decreased proportion of

fat. (The percentage of body fat during weight loss will be an

asymptotic function with the limit being the minimum capable of

sustaining life.)

Tony

[Guest guest]

Hi Tony:

Thanks for those data. But the amount of lean body mass I have lost

is not an " assumption " . It is calculated from my BF% as determined

using the US Navy method, and my total weight as measured on a scale.

Good point that the proportion of fat lost may change as my total fat

diminishes as a percent of my body weight. Time will tell. Can

anyone who has watched these data as they transitioned from pre-CR

weight to CRON weight tell me whether the proportion of fat lost

varied as their BF% declined?

Rodney.

> >>>>

> Your assumption about the amount lean body mass that you are losing

> ................ Also, I

> would assume that as your relative ratio of fat to muscle & bone

> decreases, any weight loss will also have a decreased proportion of

> fat. (The percentage of body fat during weight loss will be an

> asymptotic function with the limit being the minimum capable of

> sustaining life.)

>

> Tony

[Guest guest]

Hi folks:

For the record, the formula to use to calculate what your eventual

weight will be for a given BF% target is:

Where:

EW = Total ending weight (what one wants to find out).

SW = Total starting weight (say 171.5 pounds).

SBF% = Starting body fat percent (say 20.4).

FLPTWL = Fat loss percent total weight loss (say 80).

then:

EW = (SW x (FLPTWL - SBF%))/(FLPTWL - 10)

For example, using my data, above:

EW = (171.5 x (80 - 20.4))/70

So, EW = 146.02 pounds.

If yer like you can call this 'Rodney's Rule', and file it along with

Shurie's Solution ;;; ^ )))

Rodney.

--- In , " Rodney " <perspect1111@y...>

wrote:

> Hi Al:

>

> Further clarification:

>

> First, 16.1% is ~41% of the way from 20.4% to 10.0%. ( " I estimate

I

> am about 40% of the way from where I started, to where I want to

> be " .) I want to be down to 10% body fat. I started at 20.4% body

> fat. I am currently at 16.1%. That is 41% of the way.

>

> Second, over the period for which these data were calculated, OF

THE

> TOTAL WEIGHT I HAVE LOST, 80% of that lost weight was fat mass.

The

> other 20% of the total weight lost during that period was lean body

> mass.

>

> The reason this proportion (the 80%) is of interest to me is that,

if

> that continues to be the case ....... that is if, of the total

> weight I lose in coming months, the proportion of fat weight I lose

> continues to be 80% of the total weight lost, then I can calculate

> today that I will weigh 146.02 pounds when I reach my target BF% of

> 10%.

>

> For me that is a helpful number to have in mind. Of course many

> people will be more than happy to wait and see what it turns out to

> be, and feel no need to know ahead of time. Which is fine,

> naturally. But for those who are interested to try to calculate

> ahead of time what their target weight will be at a given target

BF%,

> it is essential to know what proportion of the total weight lost is

> going to be fat. It cannot be calculated without that number. (Of

> course there is no guarantee that for me it will continue to be

80%.

> But by the time I get down to 146 pounds I will be able to tell

> anyone who is interested what that proportion was in my case).

>

> Sorry I did not make myself clear. Is that better?

>

> Rodney.

[Guest guest]

Hi folks:

Incidentally, that formula assumes that the targeted BF% is 10%. (My

target). Some time I will 'generalize' it so that it can be used for

any selected target BF%. When I have done so I will post it.

Rodney.

> > Hi Al:

> >

> > Further clarification:

> >

> > First, 16.1% is ~41% of the way from 20.4% to 10.0%. ( " I

estimate

> I

> > am about 40% of the way from where I started, to where I want to

> > be " .) I want to be down to 10% body fat. I started at 20.4%

body

> > fat. I am currently at 16.1%. That is 41% of the way.

> >

> > Second, over the period for which these data were calculated, OF

> THE

> > TOTAL WEIGHT I HAVE LOST, 80% of that lost weight was fat mass.

> The

> > other 20% of the total weight lost during that period was lean

body

> > mass.

> >

> > The reason this proportion (the 80%) is of interest to me is

that,

> if

> > that continues to be the case ....... that is if, of the total

> > weight I lose in coming months, the proportion of fat weight I

lose

> > continues to be 80% of the total weight lost, then I can

calculate

> > today that I will weigh 146.02 pounds when I reach my target BF%

of

> > 10%.

> >

> > For me that is a helpful number to have in mind. Of course many

> > people will be more than happy to wait and see what it turns out

to

> > be, and feel no need to know ahead of time. Which is fine,

> > naturally. But for those who are interested to try to calculate

> > ahead of time what their target weight will be at a given target

> BF%,

> > it is essential to know what proportion of the total weight lost

is

> > going to be fat. It cannot be calculated without that number.

(Of

> > course there is no guarantee that for me it will continue to be

> 80%.

> > But by the time I get down to 146 pounds I will be able to tell

> > anyone who is interested what that proportion was in my case).

> >

> > Sorry I did not make myself clear. Is that better?

> >

> > Rodney.

[Guest guest]

Hi Tony:

Regarding your comment below, just for clarificaton, are you saying

that you believe there is practical evidence that that is how fat

loss behaves under CR conditions? Or are you saying that it seems

logical that that might be the way fat would decline under those

circumstances? TIA

Rodney.

> >>>>

> The percentage of body fat during weight loss will be an

> asymptotic function with the limit being the minimum capable of

> sustaining life.

>

> Tony

[Guest guest]

>>>>

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

Date: Sat Jul 31, 2004 5:59 pm

Subject: Re: Fat Loss as a Percentage of Total Weight Loss

Hi Tony:

Regarding your comment below, just for clarificaton, are you saying

that you believe there is practical evidence that that is how fat

loss behaves under CR conditions? Or are you saying that it seems

logical that that might be the way fat would decline under those

circumstances? TIA

Rodney.

> The percentage of body fat during weight loss will be an

> asymptotic function with the limit being the minimum capable of

> sustaining life.

> Tony

>>>>>

I don't have any references, but it seems to me that a 150-lb person

with 5% fat would lose fat with more difficulty than the same person

weighing 180 lb with 20% fat. I realize that weight loss involves

more than losing fat. The 150-lb person has only 7.5 lb of total fat

and much of that will be in the brain considering that the brain is

~60% fat. Whereas the 180-lb person has 36 lb of total fat, of which

3/4 can be lost.

Bodybuilders, who have low percentages of body fat achieve those low

percentages by increasing muscle bulk and thereby reducing the

proportion of fat. They don't have a smaller total weight of fat;

they have a smaller *relative* weight of fat. When weightlifters lose

weight they lose mostly muscle because they don't have much fat to

lose.

IMHO

Tony

[Guest guest]

>>>>

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

Date: Sun Jul 25, 2004 9:39 pm

Subject: Re: Fat Loss as a Percentage of Total Weight Loss

>>>>

This is a follow-up of our earlier discussion. I was just doing an

inventory of how my body has changed since I started on my ~2000-

calorie diet. My daily activities include 200 calories of exercise

(1/2 hour).

For my height (5'8 " ), the recommended minimum calories is about 2200,

so 2000 is about a 10% CR, however, if you count the 200 calories of

exercise, it leaves me only with about 1800 calories, which is an 18%

CR based on the recommended minimum.

Anyway, when I started, I weighed 167 lb, today I weigh 151 lb. Over

the first year I lost 11 lb, 2.6 lb of which were lean mass, i.e., of

the 11 lb that I lost, 76% was fat. This year, I have lost 5 lb, 2.7

lb of which was lean mass. In these last 5 pounds, only 46% was fat.

I used the U.S. Navy method for computing % Body Fat and I added it

to one of my web pages:

http://www.scientificpsychic.com/fitness/diet.html

I was also pleasantly surprised to find that my percentage of body

fat has gone from 18.3% to 13.2%. I put my progress report on:

http://www.scientificpsychic.com/fitness/pictures.html

I am going to continue on the 2000-calorie diet, but if my weight

goes below 145 lb, I will increase it slightly.

Tony Zamora

[Guest guest]

Hi Tony:

Good stuff. Thanks.

I have very recently come to realize that in my case measuring

technique can make a huge difference to the results I get for BF%,

and anything derived from it.

When using the U.S. Navy method, the key measurement is abdomen

circumference minus neck circumference (A-N). Mis-measurements in

either of these numbers, and especially when the errors happen to be

in opposite directions, can make a substantial difference to the

calculated BF% number.

Each one inch variation in A-N results in a two point difference in

BF%. Over the past few weeks, taking the measurements daily, I have

seen a three point range in calculated BF% (i.e. a 1.5 inch variation

in A-N) with no change in weight. Calculated BF% has ranged between

14.3% and 17.4%.

The U.S Navy instructions were, I now realize, nowhere near

comprehensive enough to ensure the taking of internally consistent

measurements. The neck measurement is particularly tricky, since

different rational measurements can come out with a range that is a

whole inch wide.

If anyone would like to know how I am now taking these measurements

(which I think will yield much more **consistent** results from here

on, please say so). But I realize now that the numbers I came up

with six months ago are unreliable, within a range three points wide,

for determining what my BF% was at that time.

Worse still, I do not know the exact specifics of how the U.S. Navy

measurements were taken, the data from which formed the basis of the

equation they derived. My guess is they weren't specific. They

probably just wrapped a tape measure around the neck or abdomen in

about the right place, took a quick look and noted the measurement.

That is what I was doing at first, not realizing the effect on

calculated results.

Perhaps it is not a coincidence they determined that using the

formula was accurate to within two to three points!!! Perhaps they

might have found it to be perfectly accurate had they been a bit more

refined about how they had taken the measurements?

But I think I will in future get results for BF% that are much more

consistent for me from one measurement to the next. (But may or may

not be consistent with the Navy equation depending on how it was they

took their measurements).

It will be interesting to see what proportion of the weight I lose on

the way from here to 10% BF turns out to be fat.

Rodney.

[The percentage range in my calculated BF% in the past few weeks,

using a too-casual measurement method, was 21.7%; for WC/H it was

3.0%; and for BMI it was 1.3%. One of the reasons for the smaller

ranges for BMI and WC/H is that I use an unchanging measurement for

height. Using BMI as a measure has, of course, other problems that

are unrelated to meaurement technique, and have been discussed here

previously].

> >>>>

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

> Date: Sun Jul 25, 2004 9:39 pm

> Subject: Re: Fat Loss as a Percentage of Total Weight Loss

> >>>>

>

> This is a follow-up of our earlier discussion. I was just doing an

> inventory of how my body has changed since I started on my ~2000-

> calorie diet. My daily activities include 200 calories of exercise

> (1/2 hour).

>

> For my height (5'8 " ), the recommended minimum calories is about

2200,

> so 2000 is about a 10% CR, however, if you count the 200 calories

of

> exercise, it leaves me only with about 1800 calories, which is an

18%

> CR based on the recommended minimum.

>

> Anyway, when I started, I weighed 167 lb, today I weigh 151 lb.

Over

> the first year I lost 11 lb, 2.6 lb of which were lean mass, i.e.,

of

> the 11 lb that I lost, 76% was fat. This year, I have lost 5 lb,

2.7

> lb of which was lean mass. In these last 5 pounds, only 46% was

fat.

>

> I used the U.S. Navy method for computing % Body Fat and I added it

> to one of my web pages:

> http://www.scientificpsychic.com/fitness/diet.html

>

> I was also pleasantly surprised to find that my percentage of body

> fat has gone from 18.3% to 13.2%. I put my progress report on:

> http://www.scientificpsychic.com/fitness/pictures.html

>

> I am going to continue on the 2000-calorie diet, but if my weight

> goes below 145 lb, I will increase it slightly.

>

> Tony Zamora