Re: What is Caloric Restriction?

August 1, 2004

Hi Tony:

Well here is a reply. IMO you are not talking about intermittent

fasting. You are talking about intermittent EATING ; ^ )))

That out of the way ............... As to how much one should eat

during the transition phase from one's starting weight/physique (or

whatever one wishes to call it) to full, established, stable CR

status, it seems to be clear to me that it cannot be harmful to lose

weight slowly - say at a rate of half a pound a week.

This makes it quickly clear how much one should be eating during the

transition period. Namely, two hundred to three hundred calories a

day fewer than one is burning off. If one does not know how many

calories one is burning off then experimentation over a period of a

few weeks or a couple of months should provide

enlightenment .......... at least about how much to eat during this

transition phase.

Similarly, it seems to me there should not be much confusion about

how much to eat when CR status has been achieved. One should simply

stabilize what some would call one's selected " anthropometric

characteristic " (weight? WC/H? BMI? BF%? ..........???) at a

level that one believes (hopes) represents 'ideal CR'. Since that

will mean eating more than in the transition phase, stabilizing

weight, BMI, etc. should be less challenging than the weight loss

phase. If weight is stabilized then by definition atrophy, or

wasting, or whatever you would like to call it, will not happen

unless 'ON' is inadequate.

Two difficulties arise once true CR levels have been attained it

seems to me. The first is to decide which measurement to stabilize.

The second, determining what level of that measurement is best. I

have good answers to neither of these issues.

When I reach the general range that people consider to represent CR

levels I may have an answer to the first. I would probably choose

the measure which 'jumps around' the least. Since my weight jumps

around all over the place (even on one occasion years ago rising 11

pounds in 24 hours) for sure I will not select weight as my measure.

But in four to nine months I will have pretty decent data for which

body measurement, in my case, jumps around the least. I will

probably select that one.

As for which level to choose for the selected measure ...... I

really do not know, and do not expect to know for a long time. The

reason follows.

I have posted here previously that, ***IF*** CR in humans really does

offer a potential in maximum lifespan extension similar to that in

mice, then the curve representing lifespan on the Y-axis against the

chosen body measurement on the X-axis must be extremely steep at

values of the X-axis variable BOTH above and below the optimal

point. This means small differences from the optimal level will

result in large variations in lifespan (all of them downward from the

optimum).

To explain this, we could take BMI as an example. We know maximum

lifespan at a BMI of 25 is about 110 years. We know also that

starvation (eventually death) occurs around a BMI of 12 to 13. So

if the peak in the lifespan curve, at its optimal point, is really

~160 years then the curve, which we know is not especially steep

between BMIs of 25 and 30, must rise all the way from 110 to 160 and

back down to 30 (for a number) over a BMI range of little more than

ten points. (Perhaps less than ten points. We still do not know

where the curve starts to become really steep). [if confused by

the foregoing you might want to get out a sheet of graph paper and

plot the data I have mentioned. You will quickly see the point, I

think].

So either the peak in the curve is nowhere close to 160 years, in

which case we do not need to be too concerned about getting it

exactly right. Or, a huge amount more research is needed to

determine exactly where that ideal point is for humans. My bet is

that we will not know that information for a long, long time.

But to answer your question directly ........... caloric intake

should be set to maintain that level for the chosen measure that is

believed most likely to be the one at which life expectancy is

maximized. I hope this answers at least some of the issues you raise.

Rodney.

PS # 1: Perhaps I should add that a considerable extension in

lifespan has been demonstrated in both fruit flies and mice even when

CR is started at the human-equivalent age of 60 years.

PS # 2: Also, there are people who disagree that the evidence

indicates 'every-other-day' feeding will work better than feeding

daily. But I do not think the definitive study to show that has yet

been done.

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

> I am still thinking about the paper posted by Dowling

> about Intermittent Fasting and caloric restriction.

> http://snipurl.com/4d7w

>

> Nobody commented on my post (Message 13677) which pointed out

> what were some interesting facts in the publication

> But seriously, to make good use of Walford's ideas, I feel that one

of

> the hardest issues we have to address is knowing how much to eat

(CR .......... > In animal experiments, CR is defined as the

percent of reduction in

> food provided to a group of animals, compared to the amount of food

> that a control group eats ad libitum. Typical experiments start CR

at

> an early stage in the animal's life. For mice, food is generally

> provided ad libitum until 9 weeks of age, which would be the

> equivalent to starting a CR program at the human age of 8. Because

> the diet is well balanced, no nutritional deficiencies develop, and

> the calorically restricted mice have extended life spans compared to

> the ones that are not restricted. However, adult mice that are on

> limited daily feeding regimens and consume 40% less food than those

> that are fed ad libitum have 49% lower body weights. In human terms

> this would mean that an adult person subjected to a CR diet from an

> early age would weigh 76 pounds compared to 150 pounds for one whose

> diet was unrestricted.

>

> We all started our CR programs after reaching maturity. Therefore,

we

> are big compared to how we would be if we had started CR before

> puberty. The growing body adjusts to CR by producing a smaller

body,

> just like a maple planted in a small pot will stay small and become

a

> bonzai. A small, 76-pound person will have smaller caloric

> requirements than a 150-pound person and will be able to survive and

> thrive on 40% fewer calories than the big person. What would happen

> to the 150-pound person if he/she were placed on a 40% CR diet? The

> results would probably be detrimental as mentioned in BT120YD.

>

> To me it seems obvious that the calories consumed by adults should

not

> be below the number of calories required to support the base

> metabolism and physical activity once a healthy BMI has been

attained

> (between 21 and 22). The consequence of consuming fewer calories,

> once an optimum weight has been reached, means that some necessary

> body tissues will be sacrificed and this loss may eventually lead to

> health problems.

>

> Intermittent Fasting (eating on alternate days) seems to provide the

> long life that we seek, and this may be a better way of achieving

> longevity than reducing the calories below those required by our

base

> metabolism.

>

> Tony

August 1, 2004

Perhaps, but Rae has made the point that intermittend fasting

without overall CR has not been shown to increase lifespan.

>From: " citpeks " <citpeks@...>

>Reply-

>

>Subject: [ ] What is Caloric Restriction?

>Date: Sat, 31 Jul 2004 21:42:40 -0000

>

>I am still thinking about the paper posted by Dowling

>about Intermittent Fasting and caloric restriction.

>http://snipurl.com/4d7w

>

>Nobody commented on my post (Message 13677) which pointed out

>what were some interesting facts in the publication, although there

>have been some questions on terminology like " Is there such a thing as

>non-intermittent fasting? " , to which the answer is: yes, it happens

>after death.

>

>But seriously, to make good use of Walford's ideas, I feel that one of

>the hardest issues we have to address is knowing how much to eat (CR),

>and there is also the problem of knowing what to eat (Optimum

>Nutrition), but ON is a secondary problem.

>

>In animal experiments, CR is defined as the percent of reduction in

>food provided to a group of animals, compared to the amount of food

>that a control group eats ad libitum. Typical experiments start CR at

>an early stage in the animal's life. For mice, food is generally

>provided ad libitum until 9 weeks of age, which would be the

>equivalent to starting a CR program at the human age of 8. Because

>the diet is well balanced, no nutritional deficiencies develop, and

>the calorically restricted mice have extended life spans compared to

>the ones that are not restricted. However, adult mice that are on

>limited daily feeding regimens and consume 40% less food than those

>that are fed ad libitum have 49% lower body weights. In human terms

>this would mean that an adult person subjected to a CR diet from an

>early age would weigh 76 pounds compared to 150 pounds for one whose

>diet was unrestricted.

>

>We all started our CR programs after reaching maturity. Therefore, we

>are big compared to how we would be if we had started CR before

>puberty. The growing body adjusts to CR by producing a smaller body,

>just like a maple planted in a small pot will stay small and become a

>bonzai. A small, 76-pound person will have smaller caloric

>requirements than a 150-pound person and will be able to survive and

>thrive on 40% fewer calories than the big person. What would happen

>to the 150-pound person if he/she were placed on a 40% CR diet? The

>results would probably be detrimental as mentioned in BT120YD.

>

>To me it seems obvious that the calories consumed by adults should not

>be below the number of calories required to support the base

>metabolism and physical activity once a healthy BMI has been attained

>(between 21 and 22). The consequence of consuming fewer calories,

>once an optimum weight has been reached, means that some necessary

>body tissues will be sacrificed and this loss may eventually lead to

>health problems.

>

>Intermittent Fasting (eating on alternate days) seems to provide the

>long life that we seek, and this may be a better way of achieving

>longevity than reducing the calories below those required by our base

>metabolism.

>

>Tony

>

August 1, 2004

I was reading the report on the Minnesota Starvation Study

quoted by Dean on the crsociety list Thu, 29 Jul 2004 01:17:57

-0700. It was a reposting by Derram of Dean's report at

the 2003 CR Conference.

It sounded almost hilarious until one realized that it was deadly

serious - where the subjects in the Starvation Study did it so as

not to be drafted in 1950.

Then I read Deans report and wondering what % of CRers can

actually feel a more 'spiritual' sense when they get to their goal

or is it just a prolongation of the self-absorbtion that becomes

part of the program. Dean's honesty in showing his

vulnerabilities is very unusual IMO and I thank him for letting us

in on it. As Derram said it's a terrific document to revisit.

The following post of Rodney's had brought Dean to mind. I

think that rather than projecting progress - as he does here - it

might help to have the CRers who've 'made it' enlighten us and

show us the pitfalls etc.

Canary Peg

> Hi Tony:

>

> Well here is a reply. IMO you are not talking about intermittent

> fasting. You are talking about intermittent EATING ; ^ )))

>

> That out of the way ............... As to how much one should eat

> during the transition phase from one's starting

weight/physique (or

> whatever one wishes to call it) to full, established, stable CR

> status, it seems to be clear to me that it cannot be harmful to

lose

> weight slowly - say at a rate of half a pound a week.

>

> This makes it quickly clear how much one should be eating

during the

> transition period. Namely, two hundred to three hundred

calories a

> day fewer than one is burning off. If one does not know how

many

> calories one is burning off then experimentation over a period

of a

> few weeks or a couple of months should provide

> enlightenment .......... at least about how much to eat during

this

> transition phase.

>

> Similarly, it seems to me there should not be much confusion

about

> how much to eat when CR status has been achieved. One

should simply

> stabilize what some would call one's selected " anthropometric

> characteristic " (weight? WC/H? BMI? BF%? ..........???) at a

> level that one believes (hopes) represents 'ideal CR'. Since

that

> will mean eating more than in the transition phase, stabilizing

> weight, BMI, etc. should be less challenging than the weight

loss

> phase. If weight is stabilized then by definition atrophy, or

> wasting, or whatever you would like to call it, will not happen

> unless 'ON' is inadequate.

>

> Two difficulties arise once true CR levels have been attained it

> seems to me. The first is to decide which measurement to

stabilize.

> The second, determining what level of that measurement is

best. I

> have good answers to neither of these issues.

>

> When I reach the general range that people consider to

represent CR

> levels I may have an answer to the first. I would probably

choose

> the measure which 'jumps around' the least. Since my weight

jumps

> around all over the place (even on one occasion years ago

rising 11

> pounds in 24 hours) for sure I will not select weight as my

measure.

> But in four to nine months I will have pretty decent data for

which

> body measurement, in my case, jumps around the least. I will

> probably select that one.

>

> As for which level to choose for the selected measure ...... I

> really do not know, and do not expect to know for a long time.

The

> reason follows.

>

> I have posted here previously that, ***IF*** CR in humans really

does

> offer a potential in maximum lifespan extension similar to that

in

> mice, then the curve representing lifespan on the Y-axis

against the

> chosen body measurement on the X-axis must be extremely

steep at

> values of the X-axis variable BOTH above and below the

optimal

> point. This means small differences from the optimal level will

> result in large variations in lifespan (all of them downward from

the

> optimum).

>

> To explain this, we could take BMI as an example. We know

maximum

> lifespan at a BMI of 25 is about 110 years. We know also that

> starvation (eventually death) occurs around a BMI of 12 to 13.

So

> if the peak in the lifespan curve, at its optimal point, is really

> ~160 years then the curve, which we know is not especially

steep

> between BMIs of 25 and 30, must rise all the way from 110 to

160 and

> back down to 30 (for a number) over a BMI range of little more

than

> ten points. (Perhaps less than ten points. We still do not know

> where the curve starts to become really steep). [if confused

by

> the foregoing you might want to get out a sheet of graph paper

and

> plot the data I have mentioned. You will quickly see the point, I

> think].

>

> So either the peak in the curve is nowhere close to 160 years,

in

> which case we do not need to be too concerned about getting it

> exactly right. Or, a huge amount more research is needed to

> determine exactly where that ideal point is for humans. My bet

is

> that we will not know that information for a long, long time.

>

> But to answer your question directly ........... caloric intake

> should be set to maintain that level for the chosen measure

that is

> believed most likely to be the one at which life expectancy is

> maximized. I hope this answers at least some of the issues

you raise.

>

> Rodney.

>

> PS # 1: Perhaps I should add that a considerable extension in

> lifespan has been demonstrated in both fruit flies and mice

even when

> CR is started at the human-equivalent age of 60 years.

>

> PS # 2: Also, there are people who disagree that the evidence

> indicates 'every-other-day' feeding will work better than feeding

> daily. But I do not think the definitive study to show that has yet

> been done.

August 1, 2004

and Peg: Although some people on this list are members of the

CR Society, many (including myself) are not. Thus what Dean and

post to that list is not relevant here for many. The two lists have no

affliliation and there are several differences in philosophy.

However, if there is something scientific that which is of relevance, by

all means post the study or reference (rather than " says this or

Dean says this " ) .

----------------------------------------------------------------------------

The following post of Rodney's had brought Dean to mind. I

think that rather than projecting progress - as he does here - it

might help to have the CRers who've 'made it' enlighten us and

show us the pitfalls etc.

Canary Peg

on 7/31/2004 8:53 PM, Dowling at dowlic@... wrote:

> Perhaps, but Rae has made the point that intermittend fasting

> without overall CR has not been shown to increase lifespan.

>

August 1, 2004

True, Francesca, it would be more direct of me to directly quote the study

or analysis thereof that led to 's statement, rather than quote him.

I do think, however, that much of what members of other CR organizations

have offered regarding information pertinent to CR is rather relevant to us

all.

>From: Francesca Skelton <fskelton@...>

>Reply-

>support group < >

>Subject: Re: [ ] What is Caloric Restriction?

>Date: Sat, 31 Jul 2004 23:06:53 -0400

>

> and Peg: Although some people on this list are members of the

>CR Society, many (including myself) are not. Thus what Dean and

>post to that list is not relevant here for many. The two lists have no

>affliliation and there are several differences in philosophy.

>

>However, if there is something scientific that which is of relevance, by

>all means post the study or reference (rather than " says this or

>Dean says this " ) .

>

>----------------------------------------------------------------------------

>

>The following post of Rodney's had brought Dean to mind. I

>think that rather than projecting progress - as he does here - it

>might help to have the CRers who've 'made it' enlighten us and

>show us the pitfalls etc.

>

>Canary Peg

>

>on 7/31/2004 8:53 PM, Dowling at dowlic@... wrote:

>

> > Perhaps, but Rae has made the point that intermittend fasting

> > without overall CR has not been shown to increase lifespan.

> >

>

August 1, 2004

>>>>

From: " Dowling " <dowlic@h...>

Date: Sat Jul 31, 2004 8:53 pm

Subject: RE: [ ] What is Caloric Restriction?

Perhaps, but Rae has made the point that intermittend fasting

without overall CR has not been shown to increase lifespan.

>>>>

According to the authors of the paper (http://snipurl.com/4d7w), the

mice on the Intermittent Feeding schedule ended up with a 10%

restriction in food intake, even when they had access to unlimited

food on the days that food was provided. This may mean that the mice

were just not able to eat twice as much on the days that they were

fed. Again, when talking about CR in this context, CR is measured

with respect to ad libitum consumption by the control mice.

The question remains of how we measure the degree of CR for humans and

whether restricting calories below the base metabolic rate after a

healthy BMI has been achieved makes any sense. The authors of the

study say " It may be that alternating periods of anabolism and

catabolism play a mechanistic role in triggering increases in cellular

stress resistance and the repair of damaged biomolecules or cells.

Recent findings suggest that many of the beneficial effects of IF may

result from a cellular stress response induced by the fasted state. "

In my opinion, we have no hope of being able to determine the

percentage of CR because " ad libitum " is a very fuzzy concept. It is

for this reason that I am looking for an alternative way of

determining the " proper " caloric requirements. At the same time, I am

interested in life extension and I think that I have a better chance

of achieving it by changing my food consumption schedule, than by

lowering my caloric intake below the base metabolic rate.

Tony

August 1, 2004

My point is that that we don't all hold in such awe that we take

every word he speaks as gospel. As said recently (something

like): " If you think you know everything about CR or the human body,

you're just kidding yourself " : (or something like that).

Both Dean and are (or at least used to be) quite fanatical in their

CR agendas - by their own definitions. That alone is a turn off for me (and

probably a few others). But of course we won't know who's right for a long

time (unless some of us get sick or drop dead before that).

on 8/1/2004 6:07 AM, Dowling at dowlic@... wrote:

> True, Francesca, it would be more direct of me to directly quote the study

> or analysis thereof that led to 's statement, rather than quote him.

> I do think, however, that much of what members of other CR organizations

> have offered regarding information pertinent to CR is rather relevant to us

> all.

August 1, 2004

Agreed: Mattson has shown significant benefits in stress resistance induced

by intermittent fasting, at least in animal models. As you know, Mattson is

involved in ongoing clinical trials of intermittent fasting of humans.

Hopefully this and ongoing studies will further elucidate the relative

benefits of intermittent fasting and CR, as well as other modalities of

increasing health and lifespan.

>From: " citpeks " <citpeks@...>

>Reply-

>

>Subject: [ ] RE: What is Caloric Restriction?

>Date: Sun, 01 Aug 2004 12:58:01 -0000

>

> >>>>

>From: " Dowling " <dowlic@h...>

>Date: Sat Jul 31, 2004 8:53 pm

>Subject: RE: [ ] What is Caloric Restriction?

>Perhaps, but Rae has made the point that intermittend fasting

>without overall CR has not been shown to increase lifespan.

> >>>>

>

>According to the authors of the paper (http://snipurl.com/4d7w), the

>mice on the Intermittent Feeding schedule ended up with a 10%

>restriction in food intake, even when they had access to unlimited

>food on the days that food was provided. This may mean that the mice

>were just not able to eat twice as much on the days that they were

>fed. Again, when talking about CR in this context, CR is measured

>with respect to ad libitum consumption by the control mice.

>

>The question remains of how we measure the degree of CR for humans and

>whether restricting calories below the base metabolic rate after a

>healthy BMI has been achieved makes any sense. The authors of the

>study say " It may be that alternating periods of anabolism and

>catabolism play a mechanistic role in triggering increases in cellular

>stress resistance and the repair of damaged biomolecules or cells.

>Recent findings suggest that many of the beneficial effects of IF may

>result from a cellular stress response induced by the fasted state. "

>

>In my opinion, we have no hope of being able to determine the

>percentage of CR because " ad libitum " is a very fuzzy concept. It is

>for this reason that I am looking for an alternative way of

>determining the " proper " caloric requirements. At the same time, I am

>interested in life extension and I think that I have a better chance

>of achieving it by changing my food consumption schedule, than by

>lowering my caloric intake below the base metabolic rate.

>

>Tony

>

August 1, 2004

I agree, Francesca. I certainly don't prescribe to all that anyone (Walford

included) states regarding life extension, health, diet, lifestyle, etc.

To some degree, I do hold in awe, at least for his rigorous analysis

of the science backing CR and related topics associated with health, diet,

longevity, etc. I also find the rigor and disipline of his dietary practices

rather awesome. Most folks, even if they state " I know doing X is good for

me, " will often do exactly the opposite. I know I fall into the latter

category, at least I have at certain times.

I do think information gleaned from other forums of discussion should not be

withheld from discussion in this forum, just because it might be viewed as

" extreme " or from an source outside of the membership of this forum. In my

opinion, free speech regarding all these topics from all sources available

(within some degree of reason and acceptability) is the most productive form

of discourse.

>From: Francesca Skelton <fskelton@...>

>Reply-

>< >

>Subject: Re: [ ] What is Caloric Restriction?

>Date: Sun, 01 Aug 2004 09:26:15 -0400

>

>My point is that that we don't all hold in such awe that we take

>every word he speaks as gospel. As said recently (something

>like): " If you think you know everything about CR or the human body,

>you're just kidding yourself " : (or something like that).

>

>Both Dean and are (or at least used to be) quite fanatical in their

>CR agendas - by their own definitions. That alone is a turn off for me

>(and

>probably a few others). But of course we won't know who's right for a long

>time (unless some of us get sick or drop dead before that).

>

>on 8/1/2004 6:07 AM, Dowling at dowlic@... wrote:

>

> > True, Francesca, it would be more direct of me to directly quote the

>study

> > or analysis thereof that led to 's statement, rather than quote

>him.

> > I do think, however, that much of what members of other CR

>organizations

> > have offered regarding information pertinent to CR is rather relevant to

>us

> > all.

>

August 1, 2004

Your arguments against the information provided by MR and DP here strike me

as rather " ad hominem " (i.e. " I don't the ideas presented by Joe 'cause

he's ugly " , for example.) If the bias of the source is known (as you have

suggested, they both admit to being " quite fanatical, " ) then I don't see any

problem with discussion of the merits of the ideas or information they

present.

>From: Francesca Skelton <fskelton@...>

>Reply-

>< >

>Subject: Re: [ ] What is Caloric Restriction?

>Date: Sun, 01 Aug 2004 09:26:15 -0400

>

>My point is that that we don't all hold in such awe that we take

>every word he speaks as gospel. As said recently (something

>like): " If you think you know everything about CR or the human body,

>you're just kidding yourself " : (or something like that).

>

>Both Dean and are (or at least used to be) quite fanatical in their

>CR agendas - by their own definitions. That alone is a turn off for me

>(and

>probably a few others). But of course we won't know who's right for a long

>time (unless some of us get sick or drop dead before that).

>

>on 8/1/2004 6:07 AM, Dowling at dowlic@... wrote:

>

> > True, Francesca, it would be more direct of me to directly quote the

>study

> > or analysis thereof that led to 's statement, rather than quote

>him.

> > I do think, however, that much of what members of other CR

>organizations

> > have offered regarding information pertinent to CR is rather relevant to

>us

> > all.

>

August 1, 2004

I never said that info gleaned from other forums should be withheld. This

is what I said:

" However, if there is something scientific that which is of relevance, by

all means post the study or reference (rather than " says this or

Dean says this " ) . "

And this is what you originally said:

> > Perhaps, but Rae has made the point that intermittend fasting

> > without overall CR has not been shown to increase lifespan.

____________________________________________________________

said:

I do think information gleaned from other forums of discussion should not be

withheld from discussion in this forum, just because it might be viewed as

" extreme " or from an source outside of the membership of this forum. In my

opinion, free speech regarding all these topics from all sources available

(within some degree of reason and acceptability) is the most productive form

of discourse.

> > Perhaps, but Rae has made the point that intermittend fasting

> > without overall CR has not been shown to increase lifespan.

>

August 1, 2004

Agreed: I should present the evidence or argument, rather than the

attribution to a source. I'm still searching for the specifics regarding

this issue...

>From: Francesca Skelton <fskelton@...>

>Reply-

>< >

>Subject: Re: [ ] What is Caloric Restriction?

>Date: Sun, 01 Aug 2004 10:34:53 -0400

>

>I never said that info gleaned from other forums should be withheld. This

>is what I said:

>

> " However, if there is something scientific that which is of relevance, by

>all means post the study or reference (rather than " says this or

>Dean says this " ) . "

>

>And this is what you originally said:

> > > Perhaps, but Rae has made the point that intermittend fasting

> > > without overall CR has not been shown to increase lifespan.

>____________________________________________________________

>

> said:

>

>I do think information gleaned from other forums of discussion should not

>be

>withheld from discussion in this forum, just because it might be viewed as

> " extreme " or from an source outside of the membership of this forum. In my

>opinion, free speech regarding all these topics from all sources available

>(within some degree of reason and acceptability) is the most productive

>form

>of discourse.

>

> > > Perhaps, but Rae has made the point that intermittend fasting

> > > without overall CR has not been shown to increase lifespan.

> >

>

August 1, 2004

I had anticipated your response even before I sent my email so

figured 'What the heck'

> and Peg: Although some people on this list are

members of the

> CR Society, many (including myself) are not. Thus what Dean

and

> post to that list is not relevant here for many.

As you say 'it's not 'relevant' for many' but how about the 'few' who

it might be relevant for. Quite possibly someone might be

tempted to join the CR Society list - heaven forbid - and spend

many hours reading some scientific and quite often humorous

posts ;-)

The two lists have no

> affliliation and there are several differences in philosophy.

>

> However, if there is something scientific that which is of

relevance, by

> all means post the study or reference (rather than "

says this or

> Dean says this " ) .

I would have done as you suggest here but was under the

impression that *whole posts* from one list to another would not

be tolerated (tho I see that many times priveleged persons get

away with more than someone like me).

I'm fairly new on the list and am learning whatever I can from

wherever. I'm retired and spend many hours in this pastime.

Granted it's not a pastime for most of you listees but for me it is.

My age is a hindrance for any promise of longevity beyond a few

years. I do think it behooves listees to remain 'grounded' and

not be missing the forest for the trees - not casting any personal

aspersions here Francesca.

Canary Peg

August 1, 2004

Hi Tony:

I must be missing something here. I do not understand where you

are 'coming from' when you say: " The question remains ........

whether restricting calories below the base metabolic rate after a

healthy BMI has been achieved makes any sense. "

Do you know of ANYONE who recommends that more weight should be lost

(i.e. continuing to restrict calories below calories burned) after

achieving 'ideal CRON status', whatever they believe that to be?

Anyone who does lose more weight after that point, will bring their

body fat to dangerously low levels and then start burning the body's

protein inventory, i.e. muscle, for fuel. So I cannot imagine why

anyone would consider that it would make sense. (Of course there is

a great deal of room for discusson/disagreement about how to

define 'ideal CRON status'.)

So my answer to your question, the one I quote in my first paragraph

here, is: " No it doesn't make sense " .

As regards the " proper caloric requirement " after appropriate BMI (or

BF%, or WC/H) has been reached ......... I do not doubt it will

vary widely from individual to individual. But in all cases, IMO, it

is the number of calories that results in a stable weight (or a

stable BMI, or stable WC/H, or stable BF%, or whatever it is you

think is the ideal measure of 'ideal CRON status').

If there is disagreement on these points I sure would appreciate

being enlightened about the other side of the argument.

Rodney.

> >>>>

> The question remains of how we measure the degree of CR for humans

and

> whether restricting calories below the base metabolic rate after a

> healthy BMI has been achieved makes any sense. The authors of the

> study say " It may be that alternating periods of anabolism and

> catabolism play a mechanistic role in triggering increases in

cellular

> stress resistance and the repair of damaged biomolecules or cells.

> Recent findings suggest that many of the beneficial effects of IF

may

> result from a cellular stress response induced by the fasted state. "

>

> In my opinion, we have no hope of being able to determine the

> percentage of CR because " ad libitum " is a very fuzzy concept. It

is

> for this reason that I am looking for an alternative way of

> determining the " proper " caloric requirements. At the same time, I

am

> interested in life extension and I think that I have a better chance

> of achieving it by changing my food consumption schedule, than by

> lowering my caloric intake below the base metabolic rate.

>

> Tony

August 1, 2004