Re: Re: What is CRON (was Elle magazine)

[Guest guest]

Let me add to that. I use the HB all the time in a spreadsheet.

Today I'm 69 yo, weight 178#, ht 5' 9".

That gives me a BMR of 1578.69. But I could easily be at 234# and my BMR would be 1927.42.

Of course my BMR would be higher with higher weight. So 1578.69/1927.42 is 81.9 or 18 % CR (by one measure). Actually, I was eating 3000 kcals ad libitum at 234# and growing slowly each year, so I could say 1578 + 250 kcals activity is 1828/3000 or 39% CR.

Which is it? Who cares?

178# is still too heavy by my BMI goal, weight goal, and heart capacity decreased by aging (the way I figure it). If I want to live longer I have to keep my weight below what my heart can produce, which so far, is OK.

The upshot is the HB doesn't tell me what weight I want to be, at any given age. We all know we will shrink if we live, and the heart will be challenged to support heavy weights. With any luck we can lower weight as our heart muscle declines, to whatever.

If my weight was 135# (my 20 yo wt), my BMR would be 1311, so I can drop my calorie intake to 1600 now and decline 0.2 # per day (fat, water, muscle total). I'd get to 135# in about 60 days. So is that a good thing?

No one knows the rate I should drop, but my gut tells me it's slower than that. I guarantee it would get the attention of my doctor. How about 1700 kcals and get to 135# in 107 days? Or 1750, 174 days?

I like 1800 and 479 days better.

Regards.

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

From: citpeks

Sent: Thursday, May 12, 2005 9:32 PM

Subject: [ ] Re: What is CRON (was Elle magazine)

Lorri,Saying that this is a no brainer, does not make it so. What you aresuggesting is to measure your basal metabolism for $49. OK. So nowyou know how many calories you burn. What is your percent of CaloricRestriction measured against? 1) Against your current metabolism? Or, 2) against the metabolism that you would have had eating adlibitum? CR should be calculated relative to option 2, which you didnot measure. This is where the problem comes in. If you are alreadycalorie restricted, your basal metabolism is already different fromwhat it would be otherwise.The fact that Benedict provides an average basal metabolism fora non-calorically restricted general population is what makes it agood choice as a reference point. Combined with an mid-point normalBMI of 22, you can set up a "control twin" for your height, weight,sex, age, and level of activity. The calculated caloric requirementsof this control twin can then be used as the basis for computing yourpercent caloric restriction based on your actual food consumption.Tony> This seems to be a no brainer -- Benedict is only apopulation > estimated equation and can be SIGNIFICANTLY different on anindividual basis. > People practicing CRON can have their metabolism measured (bothbally total > fitness and 24 Hour Fitness now offer this service for $49) to knowexactly how > many calories your body burns each day. From there, you can lower toachieve the > desired deficit you're looking for.> > Lorri

[Guest guest]

OK, sounds like a good way to report it.

But, the choice of BMI = 22 is arbitrary. I don;t disagree with it from risk factors data, but it's still arbitrary from a CR POV.

The slight diff is in my equation is I calculate age daily so Im 69.42 yo today, eg., and I corrected the constants slightly. I get 1588.35 at 69.00 using the additional decimal points:

66.5 + (13.75 x kg) + (5.003 x cm) - (6.775 x age)

Using their site, ambulating, I'm still 9% CR eating 1800. That's a low activity thing, I guess.

Their ambulating must be 400 kcals over their BEE. I've been using 200, for just routine getting around and add exercise/work over that.

Anyway If I ate 1983, I'd have to exercise more, because my calc's show a slight weight gain. Kinda hard to explain, but I developed this over several years, so maybe my lower BMR accounts for the difference, ie, my ambulating is 200 not 400. Another thing to consider is to account for lower metab, right?

I don't disagree with 149 as goal, but there's still the question how fast to get there.

Although my hypothetical aging chart says 176 for this year, I plan to get to 170-175 range, at least.

Regards.

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

From: citpeks

Sent: Friday, May 13, 2005 9:14 AM

Subject: [ ] Re: What is CRON (was Elle magazine)

JW,You ask "who cares?". I care. I think that scientific methodologyand quantification is the difference between art and engineering. Letus look at your own example: At your current weight, your BMR is 1595 (not 1578) according to theCornell web site:http://www-users.med.cornell.edu/~spon/picu/calc/beecalc.htmUsing multiplication factors of 1.2, 1.375, and 1.55 for sedentary,lightly active, and moderately active, your HB caloric requirementswould be 1914, 2193, and 2472 kcal, respectively. So, if you areeating 1800 calories and are moderately active, your percent CR is27%, relative to your current weight.However, you know that this is not the right weight for you. Even inmice experiments, mice fed ad libitum don't get to eat all they want.Researchers have been criticized for overfeeding control mice, andthe common practice now is to feed them enough so that they don't getoverweight. I think that a BMI of 22, which is the mid-point of thenormal weight range for humans is a good reference point. Never mindthat at age 20 you weighed 135 and had a BMI of 20.For this reason, I am advocating calculating %CR relative to a controltwin with a BMI of 22. For your height, a BMI 22 corresponds to aweight of 149 lb. The BMR of this control twin (male, 149 lb, 5'9",age 69) is 1408, and the metabolic requirements for sedentary, lightlyactive, and moderately active are 1689, 1935, and 2182 kcal,respectively. If you are eating 1800 calories and are moderatelyactive, your percent CR is 17% relative to your control twin((2182-1800)/2182)*100. I think that when we are asked what percentcaloric restriction we practice, this is the figure that we shouldreport.Tony--- In , "jwwright" <jwwright@e...>wrote:> Let me add to that. I use the HB all the time in a spreadsheet.> Today I'm 69 yo, weight 178#, ht 5' 9".> That gives me a BMR of 1578.69. But I could easily be at 234# and myBMR would be 1927.42.> Of course my BMR would be higher with higher weight. So1578.69/1927.42 is 81.9 or 18 % CR (by one measure). Actually, I waseating 3000 kcals ad libitum at 234# and growing slowly each year, soI could say 1578 + 250 kcals activity is 1828/3000 or 39% CR. > Which is it? Who cares? > > 178# is still too heavy by my BMI goal, weight goal, and heartcapacity decreased by aging (the way I figure it). If I want to livelonger I have to keep my weight below what my heart can produce, whichso far, is OK. > > The upshot is the HB doesn't tell me what weight I want to be, atany given age. We all know we will shrink if we live, and the heartwill be challenged to support heavy weights. With any luck we canlower weight as our heart muscle declines, to whatever.> If my weight was 135# (my 20 yo wt), my BMR would be 1311, so I candrop my calorie intake to 1600 now and decline 0.2 # per day (fat,water, muscle total). I'd get to 135# in about 60 days. So is that agood thing? > > No one knows the rate I should drop, but my gut tells me it's slowerthan that. I guarantee it would get the attention of my doctor. Howabout 1700 kcals and get to 135# in 107 days? Or 1750, 174 days?> I like 1800 and 479 days better.> > Regards.> > ----- Original Message ----- > From: citpeks > > Sent: Thursday, May 12, 2005 9:32 PM> Subject: [ ] Re: What is CRON (was Elle magazine)...> > The fact that Benedict provides an average basalmetabolism for> a non-calorically restricted general population is what makes it a> good choice as a reference point. Combined with an mid-pointnormal> BMI of 22, you can set up a "control twin" for your height,weight,> sex, age, and level of activity. The calculated caloricrequirements> of this control twin can then be used as the basis for computingyour> percent caloric restriction based on your actual food consumption.> > Tony>

[Guest guest]

It is my understanding that the lower calorie intake results in life extension and the mechanism is the slowing of the metabolic processes. As I recall the rats with the most CR live the longest, but we keep seeing new data. Whether that applies to humans who are already adults is another question, but it makes no diff, CR is the only thing we know extends lifespan in something.

Recognize there are no hard rules for calculating CR % for humans, just our best guess.

I accept Tony's def, simply because no one can prove it false.

There is a point I at which I can reduce my intake, before I began to lose weight. With an optimum food mix, I can minimize calories to avoid wasted calories, perhaps. But if I go below that level, I incur weight loss and that brings into play another goal, i.e., desired weight.

Desired weight or BMI is chosen by conventional medical knowledge - risk factors. But recognize the data shows that lower weight people have less heart disease risk, eg, but it doesn't prove that REDUCING weight will achieve that same risk.

So I turn to logical truths. Like what's the point of carrying an excess 50# around all the time? It requires more calories. Chances are it would be better to lose it, if it's not functional. Even excess muscle is not req'd - just enough to carry my wife to the hospital, eg.

So that brings up the req't for exercise to stay in shape, to limit body fat weight. But not to win marathons, IMO.

Pardon for getting on a roll and I can't stop.

Regards.

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

From: Logan

Sent: Friday, May 13, 2005 2:08 PM

Subject: [ ] Re: What is CRON (was Elle magazine)

> ((2182-1800)/2182)*100. I think that when we are > asked what percent caloric restriction we practice, > this is the figure that we should report.A field should be added to the group's H/W ratiodatabase to report this number. I average 32% calorierrestriction.One thing that I worry about: is it the degree ofcaloric restriction that plays the fundamentalanti-aging role or is it a slower metabolism?Logan

[Guest guest]

It is unclear, at least to me, whether or not "slowing of the metabolic

processes" has anything at all to do with the increases in longevity observed

experimentally across a large swath of evolution--from yeast to mice.

If anything it appears that, on a per weight basis, the effect of losing

weight confers a net increase in resting metabolic rate, i.e. roughly an

unchanged metabolic rate but a much smaller animal. Reductions in

core temperature that many CR folks experience may have more to do with

a reduction of the thermic effect of eating, since less eating is taking

place.

The mechanism which is conserved across biology, is the sensing, by

poorly understood mechanisms, of nutrient balance. Somehow, by sensing

reductions in nutrient balance, the organism flips a metabolic switch and

goes from carbohydrate metabolism which is in part fermentative (end product

= lactate) to metabolizing free fatty acids, a process which in biochemical

terms is largely oxidative. The driver of this metabolic gear shift

appears, in all cases, to be insulin and insulin-like growth factor(s).

But what galvanizes insulin into action? In precise molecular terms,

no one knows. Another question to ponder: the theory of "disposable

soma" suggests that when nutrients become rate limiting, for example during

starvation, the animal shifts from supporting reproduction and instead

lavishes that energy on the maintenance of somatic tissues by up-regulating

gene expression of DNA repair enzymes, etc. The resulting increase in longevity

supposedly spares the reproductive potential of organisms in the hopes

that the species will lump along once better conditions return.

One can observe this and other related phenomena in the dauer stage of

nematodes, the hibernation of bears, etc. Big question: what is it

about reducing energy that provides an increase in longevity? If

the animal must pick and choose between reproduction and the maintenance

of somatic systems, during times of sufficient nutrition it seems logical

that an INCREASE in energy would permit the animal to optimally support

both! Seventy years of experimentation paradoxically suggests just

the opposite--at least in r-selected organisms like mice. It would

be very interesting to know if indeed, calorie restriction, via the "thrifty

gene" theory or the "disposable soma" theory will hold up in K-selected

organisms such as humans. Perhaps if Macs can keep up the selective

pressure of the Big Mac for another 300,000 years we'll have the expected

gene punctuation event that leads to speciation. Uber-humans!

I doubt if the earth could stand it!

No doubt you can tell that I'm more interested in Darwinian fitness

than personal fitness. In the past year as a personal experiment

I have driven my weight both up and down from 148 to 175 and back to currently

154. (I'm 5' 9" tall for those of you itching to calculate my BMI).

So, in the push-me pull-me world of nutritional physiology I've proven

to myself that by exploiting calorie restriction and intermittent fasting

I can easily move my weight from one end of the so-called healthy range

to the other and park it indefinitely wherever I like. This

was fun, but in hind-sight really nothing new--it merely demonstrates the

relative plasticity of the human body to changes in dietary energy content.

Is anyone else in this group interested in questions such as: what are

the environmental and physiological cues the body senses and then responds

to by shifting through the physiological "gear box"? Or, what are

the molecular mechanisms that make up that response? My "sensation" is

that this group, very admirably, is more concerned with personal health

and applied biology than with theoretical biology. Does anyone know

of other chat groups interested in dietary restriction as it impacts evolution,

biochemistry and molecular biology, energy balance, anthropology, etc.?

If so, please let me know. I doubt if I have the patience required

to live to120 and even if I did, I will, in all likelihood, be "taken out"

prematurely by some extrinsic factor--like stepping off the curb in front

of an on-coming bus while thinking deeply about the ins and outs of DR!

Best Regards,

jwwright wrote:

It

is my understanding that the lower calorie intake results in life extension

and the mechanism is the slowing of the metabolic processes. As I recall

the rats with the most CR live the longest, but we keep seeing new data.

Whether that applies to humans who are already adults is another question,

but it makes no diff, CR is the only thing we know extends lifespan in

something. Recognize

there are no hard rules for calculating CR % for humans, just our best

guess.I

accept Tony's def, simply because no one can prove it false. There

is a point I at which I can reduce my intake, before I began to lose weight.

With an optimum food mix, I can minimize calories to avoid wasted calories,

perhaps. But if I go below that level, I incur weight loss and that brings

into play another goal, i.e., desired weight. Desired

weight or BMI is chosen by conventional medical knowledge - risk factors.

But recognize

the data shows that lower weight people have less heart disease risk, eg,

but it doesn't prove that REDUCING weight will achieve that same risk. So

I turn to logical truths. Like what's the point of carrying an excess 50#

around all the time? It requires more calories. Chances are it would be

better to lose it, if it's not functional. Even excess muscle is not req'd

- just enough to carry my wife to the hospital, eg. So

that brings up the req't for exercise to stay in shape, to limit body fat

weight. But not to win marathons, IMO. Pardon

for getting on a roll and I can't stop. Regards.

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

From:

Logan

Sent: Friday, May 13, 2005 2:08 PM

Subject: [ ] Re: What

is CRON (was Elle magazine)

> ((2182-1800)/2182)*100. I think that when we are

> asked what percent caloric restriction we practice,

> this is the figure that we should report.

A field should be added to the group's H/W ratio

database to report this number. I average 32% calorie

rrestriction.

One thing that I worry about: is it the degree of

caloric restriction that plays the fundamental

anti-aging role or is it a slower metabolism?

Logan

[Guest guest]

Thanks, ,

Your comment about patience intrigues me because it is my perception that I become less communicative to the youngers as I get older. The words change meanings in both the private and technical worlds.

OTOH, time moves a lot faster after 65.

There is at least one other group, of course, but I don't find any clear answers there either.

Search ?

Regards.

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

From: Albaugh

Sent: Saturday, May 14, 2005 9:50 AM

Subject: Re: [ ] Re: What is CRON (was Elle magazine)

It is unclear, at least to me, whether or not "slowing of the metabolic processes" has anything at all to do with the increases in longevity observed experimentally across a large swath of evolution--from yeast to mice. If anything it appears that, on a per weight basis, the effect of losing weight confers a net increase in resting metabolic rate, i.e. roughly an unchanged metabolic rate but a much smaller animal. Reductions in core temperature that many CR folks experience may have more to do with a reduction of the thermic effect of eating, since less eating is taking place. The mechanism which is conserved across biology, is the sensing, by poorly understood mechanisms, of nutrient balance. Somehow, by sensing reductions in nutrient balance, the organism flips a metabolic switch and goes from carbohydrate metabolism which is in part fermentative (end product = lactate) to metabolizing free fatty acids, a process which in biochemical terms is largely oxidative. The driver of this metabolic gear shift appears, in all cases, to be insulin and insulin-like growth factor(s). But what galvanizes insulin into action? In precise molecular terms, no one knows. Another question to ponder: the theory of "disposable soma" suggests that when nutrients become rate limiting, for example during starvation, the animal shifts from supporting reproduction and instead lavishes that energy on the maintenance of somatic tissues by up-regulating gene expression of DNA repair enzymes, etc. The resulting increase in longevity supposedly spares the reproductive potential of organisms in the hopes that the species will lump along once better conditions return. One can observe this and other related phenomena in the dauer stage of nematodes, the hibernation of bears, etc. Big question: what is it about reducing energy that provides an increase in longevity? If the animal must pick and choose between reproduction and the maintenance of somatic systems, during times of sufficient nutrition it seems logical that an INCREASE in energy would permit the animal to optimally support both! Seventy years of experimentation paradoxically suggests just the opposite--at least in r-selected organisms like mice. It would be very interesting to know if indeed, calorie restriction, via the "thrifty gene" theory or the "disposable soma" theory will hold up in K-selected organisms such as humans. Perhaps if Macs can keep up the selective pressure of the Big Mac for another 300,000 years we'll have the expected gene punctuation event that leads to speciation. Uber-humans! I doubt if the earth could stand it! No doubt you can tell that I'm more interested in Darwinian fitness than personal fitness. In the past year as a personal experiment I have driven my weight both up and down from 148 to 175 and back to currently 154. (I'm 5' 9" tall for those of you itching to calculate my BMI). So, in the push-me pull-me world of nutritional physiology I've proven to myself that by exploiting calorie restriction and intermittent fasting I can easily move my weight from one end of the so-called healthy range to the other and park it indefinitely wherever I like. This was fun, but in hind-sight really nothing new--it merely demonstrates the relative plasticity of the human body to changes in dietary energy content. Is anyone else in this group interested in questions such as: what are the environmental and physiological cues the body senses and then responds to by shifting through the physiological "gear box"? Or, what are the molecular mechanisms that make up that response? My "sensation" is that this group, very admirably, is more concerned with personal health and applied biology than with theoretical biology. Does anyone know of other chat groups interested in dietary restriction as it impacts evolution, biochemistry and molecular biology, energy balance, anthropology, etc.? If so, please let me know. I doubt if I have the patience required to live to120 and even if I did, I will, in all likelihood, be "taken out" prematurely by some extrinsic factor--like stepping off the curb in front of an on-coming bus while thinking deeply about the ins and outs of DR! Best Regards, jwwright wrote:

It is my understanding that the lower calorie intake results in life extension and the mechanism is the slowing of the metabolic processes. As I recall the rats with the most CR live the longest, but we keep seeing new data. Whether that applies to humans who are already adults is another question, but it makes no diff, CR is the only thing we know extends lifespan in something. Recognize there are no hard rules for calculating CR % for humans, just our best guess.I accept Tony's def, simply because no one can prove it false. There is a point I at which I can reduce my intake, before I began to lose weight. With an optimum food mix, I can minimize calories to avoid wasted calories, perhaps. But if I go below that level, I incur weight loss and that brings into play another goal, i.e., desired weight. Desired weight or BMI is chosen by conventional medical knowledge - risk factors. But recognize the data shows that lower weight people have less heart disease risk, eg, but it doesn't prove that REDUCING weight will achieve that same risk. So I turn to logical truths. Like what's the point of carrying an excess 50# around all the time? It requires more calories. Chances are it would be better to lose it, if it's not functional. Even excess muscle is not req'd - just enough to carry my wife to the hospital, eg. So that brings up the req't for exercise to stay in shape, to limit body fat weight. But not to win marathons, IMO. Pardon for getting on a roll and I can't stop. Regards.

[Guest guest]

More info:

I kinda like Tim's answers, most of the time.

On Tue, 1 Feb 2005, jwwright wrote:> January Newsweek had an article which stated something like:> lifespan is lengthened because the stress created by low> food causes the creature to adapt - delay death to reproduce> in better times.> Is that a correct idea?Pretty much - IMO.I rate something a lot like that as the #1 theory about why calorierestriction prolongs animal lifespan - on http://cr.timtyler.org/why/--__________ |im |yler http://timtyler.org/ tim@...

http://cr.timtyler.org/why/

Regards.

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

From: Albaugh

Sent: Saturday, May 14, 2005 9:50 AM

Subject: Re: [ ] Re: What is CRON (was Elle magazine)

It is unclear, at least to me, whether or not "slowing of the metabolic processes" has anything at all to do with the increases in longevity observed experimentally across a large swath of evolution--from yeast to mice. If anything it appears that, on a per weight basis, the effect of losing weight confers a net increase in resting metabolic rate, i.e. roughly an unchanged metabolic rate but a much smaller animal. Reductions in core temperature that many CR folks experience may have more to do with a reduction of the thermic effect of eating, since less eating is taking place. The mechanism which is conserved across biology, is the sensing, by poorly understood mechanisms, of nutrient balance. Somehow, by sensing reductions in nutrient balance, the organism flips a metabolic switch and goes from carbohydrate metabolism which is in part fermentative (end product = lactate) to metabolizing free fatty acids, a process which in biochemical terms is largely oxidative. The driver of this metabolic gear shift appears, in all cases, to be insulin and insulin-like growth factor(s). But what galvanizes insulin into action? In precise molecular terms, no one knows. Another question to ponder: the theory of "disposable soma" suggests that when nutrients become rate limiting, for example during starvation, the animal shifts from supporting reproduction and instead lavishes that energy on the maintenance of somatic tissues by up-regulating gene expression of DNA repair enzymes, etc. The resulting increase in longevity supposedly spares the reproductive potential of organisms in the hopes that the species will lump along once better conditions return. One can observe this and other related phenomena in the dauer stage of nematodes, the hibernation of bears, etc. Big question: what is it about reducing energy that provides an increase in longevity? If the animal must pick and choose between reproduction and the maintenance of somatic systems, during times of sufficient nutrition it seems logical that an INCREASE in energy would permit the animal to optimally support both! Seventy years of experimentation paradoxically suggests just the opposite--at least in r-selected organisms like mice. It would be very interesting to know if indeed, calorie restriction, via the "thrifty gene" theory or the "disposable soma" theory will hold up in K-selected organisms such as humans. Perhaps if Macs can keep up the selective pressure of the Big Mac for another 300,000 years we'll have the expected gene punctuation event that leads to speciation. Uber-humans! I doubt if the earth could stand it! No doubt you can tell that I'm more interested in Darwinian fitness than personal fitness. In the past year as a personal experiment I have driven my weight both up and down from 148 to 175 and back to currently 154. (I'm 5' 9" tall for those of you itching to calculate my BMI). So, in the push-me pull-me world of nutritional physiology I've proven to myself that by exploiting calorie restriction and intermittent fasting I can easily move my weight from one end of the so-called healthy range to the other and park it indefinitely wherever I like. This was fun, but in hind-sight really nothing new--it merely demonstrates the relative plasticity of the human body to changes in dietary energy content. Is anyone else in this group interested in questions such as: what are the environmental and physiological cues the body senses and then responds to by shifting through the physiological "gear box"? Or, what are the molecular mechanisms that make up that response? My "sensation" is that this group, very admirably, is more concerned with personal health and applied biology than with theoretical biology. Does anyone know of other chat groups interested in dietary restriction as it impacts evolution, biochemistry and molecular biology, energy balance, anthropology, etc.? If so, please let me know. I doubt if I have the patience required to live to120 and even if I did, I will, in all likelihood, be "taken out" prematurely by some extrinsic factor--like stepping off the curb in front of an on-coming bus while thinking deeply about the ins and outs of DR! Best Regards,