Re: Intermittent Fasting may be better than CR (was Mercola ...)

[Guest guest]

Al,

Here are some quotes from[1]:

" intermittent fasting resulted in beneficial effects that met or

exceeded those of caloric restriction including reduced serum glucose

and insulin levels "

" Both the IF and LDF paradigms are reported to result in dramatic

increases in life span in comparison to AL-fed animals " . This has a

reference to [2].

IF = intermittent (alternate-day) fasting

LDF = limited daily feeding, i.e, (CR)

AL = ad libitum

I highly recommend looking at Figure 1 of the paper which shows the

stunting in body weight of the CR animals (LDF) vs. the fairly normal

weight of the IF animals. The figure also shows that the ad libitum

vs. IF food intake to be approximately equivalent:

http://www.pnas.org/cgi/content/full/100/10/6216/F1

Tony

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

[1] Mattson, et al. " Intermittent fasting dissociates beneficial

effects of dietary restriction on glucose metabolism and neuronal

resistance to injury from calorie intake, Proc Natl Acad Sci USA, 2003

May 13; 100(10):6216-6220.

http://www.pnas.org/cgi/content/full/100/10/6216

[2] Goodrick CL, et al. " Effects of intermittent feeding upon growth,

activity, and lifespan in rats allowed voluntary exercise. " , Exp

Aging Res. 1983 Fall;9(3):203-9. PMID: 6641783

" one group maintained on an ad libitum (AL) diet and another provided

the diet every-other-day (EOD). EOD-fed rats had a mean lifespan of

124 weeks compared to 103 weeks for AL-fed rats. "

> The fact that Intermittent

> Fasting (IF) increases longevity without reducing calories compared to

> ad libitum diets

>

[Guest guest]

Hi Tony:

You often use the term " stunting " in your criticisms of CR (or what

you consider to be extreme CR, which seems to be represented by a BMI

below ~23, apparently?)

Could you please provide examples of what you call " stunting " in

humans or animals where CR was started after the animals were

physically mature? By that I mean after an age equivalent in humans

to, say, 25 years. In other words where CR was started at an age

that is likely to be relevant to humans trying to decide whether or

not to adopt a CR diet. No one here that I know of recommends it for

children, or pregnant adults.

Every time you use the term " stunting " in posts here I am left with

the impresssion you are grasping for straws in an effort to try to

bolster an insupportable case.

None of us care if mice started on CR not long after weaning, or

before maturity, end up much smaller than those that are permitted to

eat ad lib, because it has no relevance to CR in human adults.

Or do you think it does have relevance? If so, please explain how.

Rodney.

>

> ....................................

> I highly recommend looking at Figure 1 of the paper which shows the

> stunting in body weight of the CR animals (LDF) vs. the fairly normal

> weight of the IF animals. ...............................

[Guest guest]

Rodney,

I do not use the term " stunted " in a pejorative sense. The terms

" stunted " and " growth retarded " are often used in the literature to

describe the effects of CR, sometimes also called " caloric

deficiency " , e.g., PMID: 9291183

As many other people in this group, I am basically interested in

learning about nutrition and longevity. I want to avoid adopting an

extreme diet that will eventually turn out to be harmful. As I

mentioned in a previous note, several members of the CRS have reported

osteopenia as a result of CR. I would like to avoid that fate myself.

I find your comment somewhat strange:

> Every time you use the term " stunting " in posts here I am left with

> the impression you are grasping for straws in an effort to try to

> bolster an insupportable case.

I am not trying to prove anything. All I do is read the literature

and try to learn from it. Some of my comments may reflect my natural

skepticism ( " citpeks " <=> " skeptic " ). I like to keep an open mind.

If Intermittent Fasting is better than Caloric Restriction because it

provides the longevity benefits without the dietary deficiencies and

weight loss that leads to osteoporosis, why should I reject it? I

don't have any emotional investment in proving that CR is the " best "

method for living longer. On the contrary, I am ready to try

something new if it is better.

Tony

> >

> > ....................................

> > I highly recommend looking at Figure 1 of the paper which shows the

> > stunting in body weight of the CR animals (LDF) vs. the fairly normal

> > weight of the IF animals. ...............................

>

[Guest guest]

Hi Tony:

OK. Thank you. But you didn't answer as to whether you believe your

references to " stunting " in mice put on CR not long after weaning

have any relevance to a discussion of CR adopted by fully grown

adults. My opinion is that they do not, so I wonder what the reason

is that you raise the issue in a manner suggesting you believe it to

be important.

Regarding bone '''density''' .......... you may recall I have posted

a study here, done on 4000 females in China, in which the data showed

women of lower body weight do NOT have lower bone *density* despite

their lower DXA scores. They have smaller bones. They actually had

somewhat greater bone density, measured as grams per cubic

centimeter. DXA cannot differentiate.

So smaller women do not (necessarily) have porous bones, but DXA

interprets all variations in bone mass as indicating porosity,

whether they are derived from real variations in porosity, or in size

(as will inevitably be the case for lighter weight individuals).

Osteopenia and osteoporosis are a very serious problem if they

reflect porosity. Smaller intact bones while doubtless somewhat

weaker than large intact bones are not even in the same league as

porous bones.

As I have said before, I believe it is very appropriate for people on

CR to do careful, supervised, exercise with weights (I do squats) to

convince their bones that they weigh a lot more than they really do!

This will increase bone size if they are otherwise adequately fed

with the nutrients required for bone growth.

But I do not believe a DXA diagnosis of osteopenia means much to a

slim individual, because it doesn't tell them whether the low bone

mass detected reflects porosity, or simply size. I predict that in

twenty years all the DXA machines will be on the garbage heap and the

only bone mass measurements anyone will take seriously will be those

generated by MR machines, which are able to measure bone size as well

as mass, and therefore can generate real measures of porosity, or

which is the same thing, density in grams per CUBIC centimeter.

So, I believe 'CRON down to a BMI of ~20 with effective exercise' is

superior to restriction down to a BMI of ~23, say, with or without

exercise ............ because the exercise will strengthen the

bones and the longevity benefits of the reduced caloric intake will

be greater.

Rodney.

> > >

> > > ....................................

> > > I highly recommend looking at Figure 1 of the paper which shows

the

> > > stunting in body weight of the CR animals (LDF) vs. the fairly

normal

> > > weight of the IF animals. ...............................

> >

>

[Guest guest]

>

> Hi Tony:

>

> OK. Thank you. But you didn't answer as to whether you believe your

> references to " stunting " in mice put on CR not long after weaning

> have any relevance to a discussion of CR adopted by fully grown

> adults. My opinion is that they do not, so I wonder what the reason

> is that you raise the issue in a manner suggesting you believe it to

> be important.

>

I think that the stunting effects of CR are important for adults. They

teach us the maximum adult sizes that can be achieved with certain

levels of CR. For example, we know that 40% CR results in body

weights which are only 50% of the normal adult size.

Thus, a 40% CR diet for humans applied during adulthood would be more

likely to reduce life span than increase it. If a 150-pound adult

eats a 40% CR diet that can only sustain a human of half the weight

when implemented after weaning, the adult body will have to undergo

some serious shrinking if it is to survive. Such an adult would

likely have to lose half of the weight. Where will this come from?

From the muscles, the bones, or the brain?

I know that there have been some CR studies done an adult monkeys

which showed no ill effects for substantial degrees of CR. But these

monkeys just had to sit in a cage. They did not have to do the chores

that humans need to do on a daily basis or adapt and compete within a

social environment.

I believe that people should not practice more than 15% CR in

adulthood because this is the about the upper limit to which

metabolism can adapt. I consider higher levels of CR " extreme CR " and

it is not up to me to prove that extreme CR can be dangerous. The

advocates of CR are the ones who have to prove that severe CR is safe

and beneficial for health and longevity.

I think that the anecdotal reports of osteopenia and visual evidence

of decreased facial collagen

(http://www.scientificpsychic.com/ads/lisa.html) are giving us an

early warning that severe CR can be dangerous. You can ignore this at

your own peril.

Tony

[Guest guest]

Hi Tony.

You state:

" I believe that people should not practice more than 15% CR in

adulthood because this is the about the upper limit to which

metabolism can adapt. I consider higher levels of CR " extreme CR " and

it is not up to me to prove that extreme CR can be dangerous. The

advocates of CR are the ones who have to prove that severe CR is safe

and beneficial for health and longevity. "

Can you provide references with respect to 15% CR being an upper

limit to which metabolism can adapt? It is not clear what you mean

by " adapt, " given that many of us restrict beyond 15% and appear to

have adapted quite well very in terms of lower cholesterol, blood

pressure, etc., while still maintaining bone density and lean muscle

mass. (At least, I can speak about myself in this regard.)

Thanks,

-Dave

>

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

wrote:

> >

> > Hi Tony:

> >

> > OK. Thank you. But you didn't answer as to whether you believe

your

> > references to " stunting " in mice put on CR not long after weaning

> > have any relevance to a discussion of CR adopted by fully grown

> > adults. My opinion is that they do not, so I wonder what the

reason

> > is that you raise the issue in a manner suggesting you believe it

to

> > be important.

> >

>

> I think that the stunting effects of CR are important for adults.

They

> teach us the maximum adult sizes that can be achieved with certain

> levels of CR. For example, we know that 40% CR results in body

> weights which are only 50% of the normal adult size.

>

> Thus, a 40% CR diet for humans applied during adulthood would be

more

> likely to reduce life span than increase it. If a 150-pound adult

> eats a 40% CR diet that can only sustain a human of half the weight

> when implemented after weaning, the adult body will have to undergo

> some serious shrinking if it is to survive. Such an adult would

> likely have to lose half of the weight. Where will this come from?

> From the muscles, the bones, or the brain?

>

> I know that there have been some CR studies done an adult monkeys

> which showed no ill effects for substantial degrees of CR. But

these

> monkeys just had to sit in a cage. They did not have to do the

chores

> that humans need to do on a daily basis or adapt and compete within

a

> social environment.

>

> I believe that people should not practice more than 15% CR in

> adulthood because this is the about the upper limit to which

> metabolism can adapt. I consider higher levels of CR " extreme CR "

and

> it is not up to me to prove that extreme CR can be dangerous. The

> advocates of CR are the ones who have to prove that severe CR is

safe

> and beneficial for health and longevity.

>

> I think that the anecdotal reports of osteopenia and visual evidence

> of decreased facial collagen

> (http://www.scientificpsychic.com/ads/lisa.html) are giving us an

> early warning that severe CR can be dangerous. You can ignore this

at

> your own peril.

>

> Tony

>

[Guest guest]

Hi Tony:

So then, how do you explain the mice, put on CR at an age equivalent

to 60-years in human terms, living considerably longer than the

control mice which continued to be fully fed? This was first posted

here by Warren , and extensively discussed, at the time of

publication, approximately 2004 (Principal Investigator,

Spindler). And in another study 50% restricted mice lived 50%

longer? And 60% restricted mice lived 55% longer? (chart of these at

CRS, I believe on the home page.)

And when 40% restriction was applied to '60-year old' fruit flies

their mortality dropped by 80% within two days of starting

CR .............. while those that had been restricted all their

lives up to age '60', when shifted to an ad lib diet, saw *their*

mortality, also within two days, jump up to a level as if they had

never been restricted. ( Partridge, University College, London,

UK)

Of course the monkey experiment is not over yet (Dr. Barbara

Hansen). But just recently some pictures were posted on a website

which showed the restricted monkeys, first put on CR at age '50', now

the human equivalent of in their '80's or '90's, don't look

noticeably different from when the experiment started. But the fully

fed monkeys now look just like very elderly humans, on their last

legs you might say, wrinkles etc.. Dr. Hansen's presentation last

year said that the restricted monkeys appear to be living about 30%

longer than the monkeys that have not been restricted, even when

starting CR at age '50'. (I am trying to get access to these

pictures, first located by Al Pater, and permission to post some of

them here.) And the monkeys, incidentally, are fed three meals a day

every day. So the benefit in this case does not derive from any type

of fasting.

Of course we each have to make our own determinations of what makes

the most sense to each of us individually. It may turn out you are

right. But for the life of me I cannot understand your belief that

16% CR is the maximum safe restriction in the light of the data

mentioned above.

Rodney.

>

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

wrote:

> >

> > Hi Tony:

> >

> > OK. Thank you. But you didn't answer as to whether you believe

your

> > references to " stunting " in mice put on CR not long after weaning

> > have any relevance to a discussion of CR adopted by fully grown

> > adults. My opinion is that they do not, so I wonder what the

reason

> > is that you raise the issue in a manner suggesting you believe it

to

> > be important.

> >

>

> I think that the stunting effects of CR are important for adults.

They

> teach us the maximum adult sizes that can be achieved with certain

> levels of CR. For example, we know that 40% CR results in body

> weights which are only 50% of the normal adult size.

>

> Thus, a 40% CR diet for humans applied during adulthood would be

more

> likely to reduce life span than increase it. If a 150-pound adult

> eats a 40% CR diet that can only sustain a human of half the weight

> when implemented after weaning, the adult body will have to undergo

> some serious shrinking if it is to survive. Such an adult would

> likely have to lose half of the weight. Where will this come from?

> From the muscles, the bones, or the brain?

>

> I know that there have been some CR studies done an adult monkeys

> which showed no ill effects for substantial degrees of CR. But

these

> monkeys just had to sit in a cage. They did not have to do the

chores

> that humans need to do on a daily basis or adapt and compete within

a

> social environment.

>

> I believe that people should not practice more than 15% CR in

> adulthood because this is the about the upper limit to which

> metabolism can adapt. I consider higher levels of CR " extreme CR "

and

> it is not up to me to prove that extreme CR can be dangerous. The

> advocates of CR are the ones who have to prove that severe CR is

safe

> and beneficial for health and longevity.

>

> I think that the anecdotal reports of osteopenia and visual evidence

> of decreased facial collagen

> (http://www.scientificpsychic.com/ads/lisa.html) are giving us an

> early warning that severe CR can be dangerous. You can ignore this

at

> your own peril.

>

> Tony

>

[Guest guest]

Hello Dave,

The six-month semistarvation study by Keys[1] performed on human

volunteers showed that severe energy restriction decreased BMR in

absolute terms by 39% and also relative to the weight of metabolically

active tissue by 16%. There was a recent posting to a description of

that work[2]. The reports of the Biosphere experiment also mention a

less dramatic decrease of BMR.

I think that, once that you are at a normal weight, reducing your

calories below what your active tissue needs can result in loss of

essential tissues.

You say that you " restrict beyond 15% " . How do you measure this?

Try my CR calculator to see what it says:

http://www.scientificpsychic.com/health/cron1.html

Tony

[1] Keys A, Brozek J, Henschel A, Mickelsen O, HL. " The biology

of human starvation " , Minneapolis: University of Minneapolis Press, 1950.

[2] They Starved So That Others Be Better Fed: Remembering Ancel Keys

and the Minnesota Experiment

Leah M. Kalm and D. Semba

The American Society for Nutritional Sciences J. Nutr. 135:1347-1352,

June 2005

http://jn.nutrition.org/cgi/content/full/135/6/1347

===

> > >

> > > Hi Tony:

> > >

> > > OK. Thank you. But you didn't answer as to whether you believe

> your

> > > references to " stunting " in mice put on CR not long after weaning

> > > have any relevance to a discussion of CR adopted by fully grown

> > > adults. My opinion is that they do not, so I wonder what the

> reason

> > > is that you raise the issue in a manner suggesting you believe it

> to

> > > be important.

> > >

> >

> > I think that the stunting effects of CR are important for adults.

> They

> > teach us the maximum adult sizes that can be achieved with certain

> > levels of CR. For example, we know that 40% CR results in body

> > weights which are only 50% of the normal adult size.

> >

> > Thus, a 40% CR diet for humans applied during adulthood would be

> more

> > likely to reduce life span than increase it. If a 150-pound adult

> > eats a 40% CR diet that can only sustain a human of half the weight

> > when implemented after weaning, the adult body will have to undergo

> > some serious shrinking if it is to survive. Such an adult would

> > likely have to lose half of the weight. Where will this come from?

> > From the muscles, the bones, or the brain?

> >

> > I know that there have been some CR studies done an adult monkeys

> > which showed no ill effects for substantial degrees of CR. But

> these

> > monkeys just had to sit in a cage. They did not have to do the

> chores

> > that humans need to do on a daily basis or adapt and compete within

> a

> > social environment.

> >

> > I believe that people should not practice more than 15% CR in

> > adulthood because this is the about the upper limit to which

> > metabolism can adapt. I consider higher levels of CR " extreme CR "

> and

> > it is not up to me to prove that extreme CR can be dangerous. The

> > advocates of CR are the ones who have to prove that severe CR is

> safe

> > and beneficial for health and longevity.

> >

> > I think that the anecdotal reports of osteopenia and visual evidence

> > of decreased facial collagen

> > (http://www.scientificpsychic.com/ads/lisa.html) are giving us an

> > early warning that severe CR can be dangerous. You can ignore this

> at

> > your own peril.

> >

> > Tony

> >

>

[Guest guest]

Hi Tony.

Based on your CR calculator and moderate activity (I exercise 30-60

minutes per day: weights, running, and/or cycling), I am restricting

by 27-28% I would agree with Rodney that weightlifting is an

excellent way to maintain both muscle and bone strength when on CR.

Actually, it's probably good advice for everyone not on CR as well.

I certainly don't feel as if my diet is extreme. I eat 5 small but

satisfying meals per day, and I never go to bed hungry (my last meal

is always eaten less than 2 hours before retiring).

-Dave

> > > >

> > > > Hi Tony:

> > > >

> > > > OK. Thank you. But you didn't answer as to whether you

believe

> > your

> > > > references to " stunting " in mice put on CR not long after

weaning

> > > > have any relevance to a discussion of CR adopted by fully

grown

> > > > adults. My opinion is that they do not, so I wonder what the

> > reason

> > > > is that you raise the issue in a manner suggesting you

believe it

> > to

> > > > be important.

> > > >

> > >

> > > I think that the stunting effects of CR are important for

adults.

> > They

> > > teach us the maximum adult sizes that can be achieved with

certain

> > > levels of CR. For example, we know that 40% CR results in body

> > > weights which are only 50% of the normal adult size.

> > >

> > > Thus, a 40% CR diet for humans applied during adulthood would

be

> > more

> > > likely to reduce life span than increase it. If a 150-pound

adult

> > > eats a 40% CR diet that can only sustain a human of half the

weight

> > > when implemented after weaning, the adult body will have to

undergo

> > > some serious shrinking if it is to survive. Such an adult would

> > > likely have to lose half of the weight. Where will this come

from?

> > > From the muscles, the bones, or the brain?

> > >

> > > I know that there have been some CR studies done an adult

monkeys

> > > which showed no ill effects for substantial degrees of CR. But

> > these

> > > monkeys just had to sit in a cage. They did not have to do the

> > chores

> > > that humans need to do on a daily basis or adapt and compete

within

> > a

> > > social environment.

> > >

> > > I believe that people should not practice more than 15% CR in

> > > adulthood because this is the about the upper limit to which

> > > metabolism can adapt. I consider higher levels of CR " extreme

CR "

> > and

> > > it is not up to me to prove that extreme CR can be dangerous.

The

> > > advocates of CR are the ones who have to prove that severe CR

is

> > safe

> > > and beneficial for health and longevity.

> > >

> > > I think that the anecdotal reports of osteopenia and visual

evidence

> > > of decreased facial collagen

> > > (http://www.scientificpsychic.com/ads/lisa.html) are giving us

an

> > > early warning that severe CR can be dangerous. You can ignore

this

> > at

> > > your own peril.

> > >

> > > Tony

> > >

> >

>

[Guest guest]

Hi All, It seems to me that the below abstract from the [2] reference provides no evidence that intermittent fasting was not CR. The reference [1] does not regard longevity. Cheers, Al "From weaning until death, male Wistar rats were housed in activity-wheel cages with one group maintained on an ad libitum (AL) diet and another provided the diet every-other-day (EOD). EOD-fed rats had a mean lifespan of 124 weeks compared to 103 weeks for AL-fed rats. While post-weaning body weight and growth rates were reduced among the EOD-fed animals compared to AL-fed animals, there was no significant difference in growth duration. Positive correlations were observed between lifespan and estimates of growth rate and duration in the AL group but not in the EOD group; thus, little evidence was produced to support the hypothesis that growth rate is inversely related to longevity. While

the EOD feeding regimen resulted in higher activity levels later in life, wheel activity levels were actually lower in this group in early life compared to the AL group. The observation of reduced wheel activity among young rats fed EOD was replicated in a second experiment. Thus, little support was obtained for the hypothesis that increased activity mediates the beneficial effects of dietary restriction on longevity, unless this mechanism is active late in the lifespan."citpeks <citpeks@...> wrote: Al,Here are some quotes

from[1]:"intermittent fasting resulted in beneficial effects that met orexceeded those of caloric restriction including reduced serum glucoseand insulin levels""Both the IF and LDF paradigms are reported to result in dramaticincreases in life span in comparison to AL-fed animals". This has areference to [2].IF = intermittent (alternate-day) fastingLDF = limited daily feeding, i.e, (CR)AL = ad libitumI highly recommend looking at Figure 1 of the paper which shows thestunting in body weight of the CR animals (LDF) vs. the fairly normalweight of the IF animals. The figure also shows that the ad libitumvs. IF food intake to be approximately equivalent:http://www.pnas.org/cgi/content/full/100/10/6216/F1Tonyhttp://www.scientificpsychic.com/fitness/index.html[1] Mattson, et al. "Intermittent fasting dissociates beneficialeffects of dietary restriction on glucose metabolism and neuronalresistance to injury from calorie intake, Proc Natl Acad Sci USA, 2003May 13; 100(10):6216-6220.http://www.pnas.org/cgi/content/full/100/10/6216[2] Goodrick CL, et al. "Effects of intermittent feeding upon growth,activity, and lifespan in rats allowed voluntary exercise.", ExpAging Res. 1983 Fall;9(3):203-9. PMID: 6641783"one group maintained on an ad libitum (AL) diet and another providedthe diet every-other-day (EOD). EOD-fed rats had a mean lifespan of124 weeks compared to 103 weeks for AL-fed rats."> The fact that Intermittent> Fasting (IF) increases longevity without reducing calories compared to> ad libitum diets>

Building a website is a piece of cake. Small Business gives you all the tools to get online.

[Guest guest]

It was my impression that both of the studies you cite followed a

basic regimen of 12-36 (eat 12 hours, fast 36 hours), and not 24-24.

Bruce Long (who does both CR and 12-36 IF)

>...It may be foolish to constantly starve

>yourself in the hope of living longer. The fact that Intermittent

>Fasting (IF) increases longevity without reducing calories compared to

>ad libitum diets is a very powerful counter-example to CR.

>Intermittent Fasting is accomplished by eating nothing for 24 hours

>(except water and electrolytes) and everything you want for 24 hours

>(nutritious food, of course). If you set the cut-off time as 9AM,

>then you can always have breakfast on fasting days *before* 9AM and

>nothing until 9AM the next day. On non-fasting days, you can eat

>anything *after* 9AM. In animal experiments, Intermittent Fasting

>does not cause the stunting in body size caused by CR.

....

>Here are some quotes from[1]:

> " intermittent fasting resulted in beneficial effects that met or

>exceeded those of caloric restriction including reduced serum glucose

>and insulin levels "

>

> " Both the IF and LDF paradigms are reported to result in dramatic

>increases in life span in comparison to AL-fed animals " . This has a

>reference to [2].

>

>IF = intermittent (alternate-day) fasting

>LDF = limited daily feeding, i.e, (CR)

>AL = ad libitum

>

>I highly recommend looking at Figure 1 of the paper which shows the

>stunting in body weight of the CR animals (LDF) vs. the fairly normal

>weight of the IF animals. The figure also shows that the ad libitum

>vs. IF food intake to be approximately equivalent:

>

>http://www.pnas.org/cgi/content/full/100/10/6216/F1

>

>Tony

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

>

>[1] Mattson, et al. " Intermittent fasting dissociates beneficial

>effects of dietary restriction on glucose metabolism and neuronal

>resistance to injury from calorie intake, Proc Natl Acad Sci USA, 2003

>May 13; 100(10):6216-6220.

>http://www.pnas.org/cgi/content/full/100/10/6216

>

>[2] Goodrick CL, et al. " Effects of intermittent feeding upon growth,

>activity, and lifespan in rats allowed voluntary exercise. " , Exp

>Aging Res. 1983 Fall;9(3):203-9. PMID: 6641783

> " one group maintained on an ad libitum (AL) diet and another provided

>the diet every-other-day (EOD). EOD-fed rats had a mean lifespan of

>124 weeks compared to 103 weeks for AL-fed rats. "