Re: Re: Something Paradoxical Here?

[Guest guest]

Right. I don't find that site useful.

I find this equation fairly accurate for BMR and add then add whatever exercise I do:

bmr=13.7*wt(kg) + 5*ht(cm) - 6.8*age + 66

My BMR is about 1600 kcals. For walking at 3mph, I add 300 kcals per hour. 1800 kcals holds my weight, if I do not exercise at all, so the amount added for up-and-around (getting out of bed and doing chores), is about 200 kcals. With fairly accurate measurements of caloric intake, and exercise expenditure, I can predict quite nicely the next mornings weight change.

If I did 8 hours of work on the roof for example, or building a garage, the amount of exercise is quite unpredictable probably because the temperature has a lot to do with it, but I suspect it's at least 100 kcals per hour. Office work is almost like watching TV - classify that in the up-and-around.

To answer your question, I worked the equation backwards and got 212 that will be supported by 1800 kcals with no exercise. That's for my and height. Drop intake to 1700 and I would lose 0.38 #. If I do 300 kcals, I would lose 1.5 #. Now at 178 #, I would gain 0.8 # at 1800 kcals and no exercise. I do 300 kcals and lose 0.3 #. At 1700 kcals, I lose 0.7 #. So it's a tricky combination of exercise, BMR, and intake for a given weight. Thanks for the question. I see now I need to drop intake to 1700 for a while.

Try plotting the equation for your weight, height and age.

One other comment, is that I do mostly low fat lacto vegetarian and it's relatively easy to estimate the calories as opposed to meats, I guess due to the fat content.

Regards.

----- Original Message -----

From: Rodney

Sent: Thursday, March 18, 2004 7:57 AM

Subject: [ ] Re: Something Paradoxical Here?

Hi folks:Further to this earlier post of mine (below). Doing the same 'reverse' calculation, the -Benedict equation says my weight would drop to 116.2 pounds if I maintained a daily intake of 1800 calories.I must be missing something here. Or else /Benedict is totally out to lunch. So far out to lunch that it is a bit scary. Has anyone else checked what would happen to their weight according to -Benedict if they were to maintain a daily caloric intake of 1800? http://www.exrx.net/Calculators/CalRequire.html And do you get numbers for your predicted weight anywhere near as ridiculous as I seem to be getting? Or, if you actually have been consuming 1800 calories a day for a while, is your weight anywhere remotely close to that predicted for you by -Benedict?[i am beginning to wonder if I am making some very dumb mistake in my calculations. But right now it seems to me that what I have been told by a WeightWatchers franchisee (posted here a few months back) makes a lot more sense than -Benedict.] Rodney.> Hi folks:> > Something not quite right about this. Anyone got the explanation?> > I used the 'caloric requirement' calculator at ................. > www.exrx.net/calculators/calrequire ........ to calculate my daily > caloric requirement (2279 calories) at my set point - which I think I > do know fairly accurately, my early 20s endurance training fit weight.> > Then I calculated what 25% and 30% restriction would do to that > number (reduces it to 1600 to 1700 calories per day, approximately).> > THEN ....... I used the same calculator in reverse .......... that > is, I used it to check what body weight (according to the calculator, > that is based on the -Benedict equation) those 1600 to 1700 > calories would support on a sustained basis. I.E. I used it to > answer the question "given my height, age, etc., for what body weight > is the 1600 to 1700 calories the 'caloric requirement' "?> > The answer is quite sobering. My set point is ~170 pounds. > According to -Benedict 1655 calories would maintain a weight of > 100 pounds.> > As usual, when my weight recently dropped below 168 I started to > look 'gaunt'. Someone has already noted my now-gaunt appearance.> > Clearly it would be ridiculous to drop to 100 pounds. (Indeed it may > be ridiculous to drop to even 150 pounds). My BF% at 100 pounds > would be minus 26%. > > Not the first time the data appear to be internally inconsistent.> > Rodney.

[Guest guest]

Rodney: everyone's metabolic efficiency is different. Are they accounting

for this? I consume anywhere between 1500-1800 a day. I weigh about 118

lbs. (And as you know, I'm female)

on 3/18/2004 8:57 AM, Rodney at perspect1111@... wrote:

> Or, if you actually have been consuming 1800

> calories a day for a while, is your weight anywhere remotely close to

> that predicted for you by -Benedict?

[Guest guest]

I think the problem with many formulas of this type is the concept of Average.

Anyone who CRONs is not average and the formulas will not apply.

Positive Dennis

Rodney wrote:

Hi folks:

Further to this earlier post of mine (below). Doing the

same 'reverse' calculation, the -Benedict equation says my

weight would drop to 116.2 pounds if I maintained a daily intake of

1800 calories.

I must be missing something here. Or else /Benedict is totally

out to lunch. So far out to lunch that it is a bit scary.

Has anyone else checked what would happen to their weight according

to -Benedict if they were to maintain a daily caloric intake of

1800? http://www.exrx.net/Calculators/CalRequire.html

And do you

get numbers for your predicted weight anywhere near as ridiculous as

I seem to be getting? Or, if you actually have been consuming 1800

calories a day for a while, is your weight anywhere remotely close to

that predicted for you by -Benedict?

[i am beginning to wonder if I am making some very dumb mistake in my

calculations. But right now it seems to me that what I have been

told by a WeightWatchers franchisee (posted here a few months back)

makes a lot more sense than -Benedict.]

Rodney.

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

wrote:

> Hi folks:

>

> Something not quite right about this. Anyone got the explanation?

>

> I used the 'caloric requirement' calculator at .................

> www.exrx.net/calculators/calrequire ........ to calculate my daily

> caloric requirement (2279 calories) at my set point - which I think

I

> do know fairly accurately, my early 20s endurance training fit

weight.

>

> Then I calculated what 25% and 30% restriction would do to that

> number (reduces it to 1600 to 1700 calories per day, approximately).

>

> THEN ....... I used the same calculator in reverse ..........

that

> is, I used it to check what body weight (according to the

calculator,

> that is based on the -Benedict equation) those 1600 to 1700

> calories would support on a sustained basis. I.E. I used it to

> answer the question "given my height, age, etc., for what body

weight

> is the 1600 to 1700 calories the 'caloric requirement' "?

>

> The answer is quite sobering. My set point is ~170 pounds.

> According to -Benedict 1655 calories would maintain a weight

of

> 100 pounds.

>

> As usual, when my weight recently dropped below 168 I started to

> look 'gaunt'. Someone has already noted my now-gaunt appearance.

>

> Clearly it would be ridiculous to drop to 100 pounds. (Indeed it

may

> be ridiculous to drop to even 150 pounds). My BF% at 100 pounds

> would be minus 26%.

>

> Not the first time the data appear to be internally inconsistent.

>

> Rodney.

[Guest guest]

The problem with the katch mcardle is it uses lean body mass, I think. LBM is defined as total minus fat, right?

Regards.

----- Original Message -----

From: Dennis De Jarnette

Sent: Thursday, March 18, 2004 10:14 AM

Subject: Re: [ ] Re: Something Paradoxical Here?

I think the problem with many formulas of this type is the concept of Average. Anyone who CRONs is not average and the formulas will not apply. Positive DennisRodney wrote:

Hi folks:Further to this earlier post of mine (below). Doing the same 'reverse' calculation, the -Benedict equation says my weight would drop to 116.2 pounds if I maintained a daily intake of 1800 calories.I must be missing something here. Or else /Benedict is totally out to lunch. So far out to lunch that it is a bit scary. Has anyone else checked what would happen to their weight according to -Benedict if they were to maintain a daily caloric intake of 1800? http://www.exrx.net/Calculators/CalRequire.html And do you get numbers for your predicted weight anywhere near as ridiculous as I seem to be getting? Or, if you actually have been consuming 1800 calories a day for a while, is your weight anywhere remotely close to that predicted for you by -Benedict?[i am beginning to wonder if I am making some very dumb mistake in my calculations. But right now it seems to me that what I have been told by a WeightWatchers franchisee (posted here a few months back) makes a lot more sense than -Benedict.] Rodney.

[Guest guest]

Dr. Masoro (famous CR researcher with credentials

equaling or exceeding Dr. Roy Walford) has shown that

human CRONie metabolism is almost identical in efficiency

to non-CRONies, after the initial transient adaptive effects

have settled down to equilibrium. -- Warren

PS: There may be an opportunity to hear Dr. Masoro

in person coming up soon. Dr. Masoro has written the overall

best Calorie Restriction overview article ever published in

the history of CR (IMHO). It was glum about prospects for

application to humans, however. Sorry. :-((

======================

On 18 Mar 2004, Dennis De Jarnette wrote:

>

> I think the problem with many formulas of this type is

> the concept of Average.

Actually the fact that the equation can be written down

so precisely, and applies so universally (within a small

amount of statistical variability) is the power of the

equations. It applies universally on average very accurately.

There is a formula for the standard error, so one can

actually compute how uncertain the answer is. The deviation

from average is not very large, and won't be seen within

measurement error for most scientific instruments.

>

> Anyone who CRONs is not average and the formulas

> will not apply.

Actually CRONies are quite average relative to non-CRONies,

at least in terms of measurement data fitting the equations.

The equations apply to a very high level of accuracy,

as Masoro comments in his CR review article. The level

of deviation is so tiny, that CR scientists have argued

about the direction of deviations for decades. The exact

direction of the tiny deviation for CRONies was recently decided

(because of improvements in the laboratory equipment and

measurement procedures), which is one of the most interesting

features of Masoro's CR overview article.

If the opportunity to ever hear Dr. Masoro speak in pubic

ever arises, you want to be there. It is like listening

to Dr. Weindruch (I was there to hear him

reminisce for about 10 minutes about Dr. Walford, and what

it was like working with Roy, all captured on my voice

recorder!). These CRON researchers have published

many 100s of papers, have worked with the mice and

in the CR laboratories with the animal cohorts,

and they know almost everything. And they can tell you

what is not yet known too. -- Warren

[Guest guest]

That may be right. The BMR should go up as a person gets thinner, because more heat is lost to the environment simply because of the surface area versus mass. The idea of adipose not bioactive, is I think questionable - something has to heat it, and some fat (brown fat?) has mitochondria, as I recall.

Anyway, I see the equation may produce silly results at say 120 #, at least for a man.

Page A-61 of Modern Nutrition table for me 1.5 to 2 meters, 49.5 to 88 kg, BMR is 1450 to 1900 per day. Looks like a line, that says 1530 for 124#, but also short, 63". This can't be right - It says I'm too short (ha).

So BMR increases for less surface to mass, but decrease with mass?

Regards.

----- Original Message -----

From: Rodney

Sent: Thursday, March 18, 2004 7:28 PM

Subject: [ ] Re: Something Paradoxical Here?

Hi folks:Thanks to everyone who responded to my 'Paradox' post. As a result I have suddenly come to realize the key issue about the differences between -Benedict and Katch-McArdle - and the differences are profound.As Jw noted, the latter is a function of only lean body mass (plus a constant term). Take the example of someone who measures their BMR using Katch-McArdle while doing a good job on CR - i.e. while maintaining their non-adipose tissues like bone mass, muscles and brain. Suppose they lose 30 pounds of body weight ONLY IN THE FORM OF FAT. Using Katch-McArdle they will still have the same identical BMR after they have lost the weight, as they had calculated using Katch-McArdle before the weight loss, because their LBM has not changed. And since adipose tissue, as I understand it, is not metabolically active, when you lose 30 pounds of it your BMR SHOULD be unchanged.But in stark contrast, using the -Benedict equation, in which simple total weight is a major variable in the calculation, the number you come up with will be a lot less at lower weights, even though you have probabably only lost metabolically inactive (fat) tissue. It was more than 400 calories less in the example I calculated for myself.Certainly carrying less weight around will consume fewer calories. But that is in the activity part of the calculation. Not the BMR part.CONCLUSION: I am beginning to think that the -Benedict equation produces nonsense results if used for people much above or below 'average' weights. (Who knows, perhaps at average weights too?)Rodney.

[Guest guest]

I just plotted the KM (15% body fat), and HB alongside the A-61 MN data and they come closely together at about 175#, which just happens to be where I am, more or less. I guess that's why I think the HB works. The A-61 data looks like it would fit better to the CR low BF person. But the diff (1350-1550) at 125# is only 13%, probably within the noise for BMR calculations.

Regards.

----- Original Message -----

From: Rodney

Sent: Thursday, March 18, 2004 7:28 PM

Subject: [ ] Re: Something Paradoxical Here?

Hi folks:Thanks to everyone who responded to my 'Paradox' post. As a result I have suddenly come to realize the key issue about the differences between -Benedict and Katch-McArdle - and the differences are profound.As Jw noted, the latter is a function of only lean body mass (plus a constant term). Take the example of someone who measures their BMR using Katch-McArdle while doing a good job on CR - i.e. while maintaining their non-adipose tissues like bone mass, muscles and brain. Suppose they lose 30 pounds of body weight ONLY IN THE FORM OF FAT. Using Katch-McArdle they will still have the same identical BMR after they have lost the weight, as they had calculated using Katch-McArdle before the weight loss, because their LBM has not changed. And since adipose tissue, as I understand it, is not metabolically active, when you lose 30 pounds of it your BMR SHOULD be unchanged.But in stark contrast, using the -Benedict equation, in which simple total weight is a major variable in the calculation, the number you come up with will be a lot less at lower weights, even though you have probabably only lost metabolically inactive (fat) tissue. It was more than 400 calories less in the example I calculated for myself.Certainly carrying less weight around will consume fewer calories. But that is in the activity part of the calculation. Not the BMR part.CONCLUSION: I am beginning to think that the -Benedict equation produces nonsense results if used for people much above or below 'average' weights. (Who knows, perhaps at average weights too?)Rodney.

[Guest guest]

I recall studies that show that weight loss includes lean body mass, fat, and bone mass. Logically as you get heavier the bones have to be stronger, the muscles bigger to carry the weight. So in decline the body adjusts those downward. Saving lean muscle is hard to do.

And yes, I believe that heart will reduce in size also. We already know that an enlarged heart will reduce in size. LARGE weight losses must be over long periods to be safe, IMO. There is a "romantic" idea the body would "naturally" conserve organ tissue, but I don't recall a single study that says that, and we've discussed it before at length in the CR groups.

Regards.

----- Original Message -----

From: Rodney

Sent: Friday, March 19, 2004 7:08 AM

Subject: [ ] Re: Something Paradoxical Here?

Hi folks:More problems with calculating BMR: I have already concluded -Benedict makes no sense. Now here are some thoughts about Katch-McArdle.Logically, **if** you accept Katch-McArdle, then it follows that CR means loss of lean body mass.Think about it. Taking me as an example. Suppose my weight starts out stable eating 2200 calories at a set point around 170 lbs. Then, when I first reduce caloric intake I lose weight through loss of fat. So my BF% will drop from its original ~21%. When I eventually decide to stabilize my weight and increase my calorie consumption to the level necessary to do so, Katch-McArdle says it will be at the same 2200 calories that will be necessary - since in the Katch-McArdle equation the only variable is lean body mass.THE ONLY WAY I CAN REDUCE MY CALORIE CONSUMPTION ON A LONG TERM BASIS, ACCORDING TO THEIR EQUATION, IS TO REDUCE LEAN BODY MASS. So it follows from their equation that, after the initial loss of fat, if I want to reduce calorie consumption by 25% or 30% or 35% from my baseline in the long term, then I have to lose 25% or 30% or 35% of my lean body mass.So, of the lean body mass I possessed at the outset, which should I feel enthusiastic about losing? Presumably not bone or brain (!). I am not too enthusiastic about losing too much muscle either - one does need to be healthily ambulatory. Heart muscle? Liver, with its stores of nutrients? Kidneys with their garbage-truck function? Skin? Hair? (!!!) Any suggestions? Of course Warren already raised this issue here a month or so ago. Perhaps he would like to weigh in and straighten me out.The alternative, of course, is to consign Katch-McArdle to the ash can too.Rodney.