Re: Need Advice on Stabilizing Weight (Optimum BMI for longevity)

[Guest guest]

The notion of having as much fat as possible while eating as little as

possible for longevity seems contradictory. Dr. Walford thought that

you needed to have a BMI of less than 20 (BT120YD, p.228) to live

long. However, the following study of over 1 million people found

that a BMI of around 23 was associated with the greatest longevity

(PMID: 10511607). Needless to say, when this paper was discussed in

the CRS group last year, there was much skepticism. Even

Delaney expressed his doubts.

However, facts are hard to ignore. Even though we know that lower

BMIs are associated with less diabetes and cancer, and that lower BMIs

require fewer calories, it was not the low BMI people who lived the

longest. Go figure.

Tony Zamora

Calle EE, Thun MJ, Petrelli JM, C, Heath CW Jr. Body-mass

index and mortality in a prospective cohort of U.S. adults. N Engl J

Med. 1999 Oct 7;341(15):1097-105. PMID: 10511607

In a prospective study of more than 1 million adults in the United

States (457,785 men and 588,369 women), 201,622 deaths occurred during

14 years of follow-up.

In healthy people who had never smoked, the nadir of the curve for

body-mass index and mortality was found at a body-mass index of 23.5

to 24.9 in men and 22.0 to 23.4 in women.

> > > > >

> > > > > Hi folks:

> > > > >

> > > > > Remember Warren 's post here several years ago to the

> > > effect

> > > > > that: " Among the life-extended CR mice, the ones that lived

> > the

> > > > > absolute longest were those with the highest body fat. "

> They

> > > were

> > > > > all fed identically of course.

> > > > >

> > > > > The question is: " What can we do to effectively implement

> what

> > > the

> > > > > mice were up to in our own lives? "

> > > > >

> > > > > Any ideas?

> > > > >

> > > > > Rodney.

> >

>

[Guest guest]

Does anyone remember the FIRKO (Fat-specific Insulin Receptor Knock

out) mice that were genetically engineered to not store fat? Ray

Kurzweil mentioned the study done on them by the Joslin Diabetes

Center at Harvard Medical School in the section on calorie restriction

in his book Fantastic Voyage. They ate as much as they wanted but had

50%-70% less fat than regular mice. They also lived 18% longer. So in

this study, we have ad lib eating and low bodyfat correlated with

longevity, which is just the opposite of the others we are talking

about. I am not sure what to make of that.

Jeff

> > > > > >

> > > > > > Hi folks:

> > > > > >

> > > > > > Remember Warren 's post here several years ago to the

> > > > effect

> > > > > > that: " Among the life-extended CR mice, the ones that lived

> > > the

> > > > > > absolute longest were those with the highest body fat. "

> > They

> > > > were

> > > > > > all fed identically of course.

> > > > > >

> > > > > > The question is: " What can we do to effectively implement

> > what

> > > > the

> > > > > > mice were up to in our own lives? "

> > > > > >

> > > > > > Any ideas?

> > > > > >

> > > > > > Rodney.

> > >

> >

>

[Guest guest]

Hi Tony:

We have, of course, had this discussion previously. There is another

somewhat similar study I am sure you will recall. It was posted here

at the time of its publication a year or two ago. It found a BMI of

26 or 27 to be associated with maximum lifespan.

Each of us here is different. We each have different approaches to

what we think is healthy to eat. We have read different materials on

nutrition over the past thirty years. Many of us, experimented on

ourselves and watched the results. Also we will not all be persuaded

by the same types of evidence, and will even react differently to the

results reported in an individual published paper. I know there are

a few here (certainly not you, and hopefully not me!) who are very

impressed by information to be found on websites that many believe to

be on the lunatic fringe of health/nutrition. And some will believe

claims when absolutely no serious evidence is provided to support

them.

Given all the above we each will have our own opinions, and have

to 'place our bets' based on our personal individual assessments.

However, the paper you reference has serious issues, imo. For a

start people who are 'naturally slim' often are slim for reasons that

are not good for their health. For example those who can, and do,

eat as much as they like and never put on weight clearly must have

intestinal absorption problems which are not likely in the longer run

to be beneficial for health. Others who do not have what is

colloquially termed 'a healthy appetite' are also suspect. I cannot

provide evidence to support this but it is intuitively obvious to me

that these people are in some way sub-clinically sick. Those who

have a 'very healthy' appetite it seems likely to me are likely to be

healthier. (But as we know, it is very necessary to restrain that

appetite to reap the benefits of that good health.) These are

factors that will cause low weight subjects in studies of this kind

to exhibit higher mortality. But they have nothing to do with

caloric restriction.

IMO, the biggest flaw in this and similar papers is that if you

really want to find out the effects of caloric restriction (or any

other 'treatment' for that matter) YOU HAVE TO START OFF AT THE

BEGINNING OF THE STUDY BY SELECTING RANDOMLY TWO OR MORE GROUPS SO

THAT THE MEMBERS OF EACH GROUP ARE IDENTICAL AT THE OUTSET. Then

each group should be subjected a particular 'treatment', and the

differences that emerge between the groups observed. But in the

paper you reference this was not done. The members of each group

selected themselves by virtue of their body weight. And the

treatments were all the same ........ essentially just: 'continue to

do what you have been doing'.

Needless to say, this tells us nothing about how long these people

would have lived if, rather than continuing to do what they had

always done, they had instead been subjected to, say, 30% caloric

restriction with good nutrition.

As you know, such caloric restriction experiments HAVE BEEN DONE in

many many species, from yeasts up to mammals, including monkeys which

are very closely related to us.

The evidence from those studies, most observers agree, unequivocally

indicates that both average and maximum lifespan are greatly extended

if, rather than 'continuing to do what you have always done' calories

are dramatically restricted instead.

We do know that in nearly all the animal experiments restricting

calories by 30%, 40% or 50% below ad lib has been associated with

dramatic increases in lifespan - for a number, 30%, 40% or 50%

increases. This includes emerging data suggesting a 30% extension of

lifespan in monkeys started on 30% CR at the human-equivalent age of

50.

What this tells me is that if the one million subjects in the paper

you referenced, rather than 'continuing to do what they have always

been doing' had instead restricted caloric intake by, for example,

30%, then, as in the animal studies, they almost all would have lived

substantially longer than they actually did.

You don't have to agree with this, of course. Nor does anyone else.

Nevertheless, to take the opposing view I think you have to explain

the basis of your apparent belief that humans would be the only

species not to benefit dramatically from caloric restriction.

We each have to take the responsibility for placing our own bets. My

bets are placed (in effect) on a BMI appreciably below 23, or 26 -

although I do not use BMI, specifically, as a major criterion.

Indeed another flaw in the study is the supposition that BMI is a

sensible measure to use for the purpose.

There are many other criteria most of us here are well aware of.

(For those not familiar with these indicators, most of them are to be

found in the WUSTL study, often referenced here). A BMI of 18 may be

appropriate for some people. A BMI of 23 may be more appropriate for

others. And that is a huge difference. But measures like BF%,

fasting insulin, SBP, PP, fasting CRP, IGF-1, ratio triglycerides to

HDL, carotid IMT, .......... seem to me to make a lot of sense,

especially when these indicators are viewed as a group in assessing

an appropriate degree of restriction.

Jmo, fwiw.

Rodney.

> > > > > >

> > > > > > Hi folks:

> > > > > >

> > > > > > Remember Warren 's post here several years ago to

the

> > > > effect

> > > > > > that: " Among the life-extended CR mice, the ones that

lived

> > > the

> > > > > > absolute longest were those with the highest body fat. "

> > They

> > > > were

> > > > > > all fed identically of course.

> > > > > >

> > > > > > The question is: " What can we do to effectively

implement

> > what

> > > > the

> > > > > > mice were up to in our own lives? "

> > > > > >

> > > > > > Any ideas?

> > > > > >

> > > > > > Rodney.

> > >

> >

>

[Guest guest]

Rodney,

Fontana's paper, which was posted by Al, seems to say that if you are

thin, you may not be able to benefit much from CR. Whereas if you

have a higher percentage of body fat, CR may be more beneficial.

Generally, people are expected to gain weight as they age. The reason

for this is that they don't change their eating habits, but their BMR

decreases with age, so they get fat. In order to maintain a normal

weight as you age, you have to gradually cut down your calories.

Keeping your weight constant as you age is a form of Caloric

Restriction. A 5'9 " , 150-lb, 30-year old male has a BMR of 1632 kcal

per day. At age 60 for this same weight the BMR is 1482. This is a

difference of 150 kcal per day which corresponds to 9.2% CR. By age

90, the BMR is 1332 kcal per day which is 300 kcal less or 18.4% CR to

maintain the weight.

It may be that just keeping your weight in the middle of the normal

BMI range as you age is sufficient CR to reduce mortality.

I think this paper stated that centenarians ate a varied diet and

tended to keep their body weight fairly steady without great variations:

Cicconetti P, Tafaro L, Tedeschi G, Tomolillo MT, Ciotti V, Troisi G,

Marigliano V., Lifestyle and cardiovascular aging in centenarians.

Arch Gerontol Geriatr Suppl. 2002;8:93-8. PMID: 14764379

Tony

> >

> > The notion of having as much fat as possible while eating as little

> as

> > possible for longevity seems contradictory. Dr. Walford thought

> that

> > you needed to have a BMI of less than 20 (BT120YD, p.228) to live

> > long. However, the following study of over 1 million people found

> > that a BMI of around 23 was associated with the greatest longevity

> > (PMID: 10511607). Needless to say, when this paper was discussed in

> > the CRS group last year, there was much skepticism. Even

> > Delaney expressed his doubts.

> >

> > However, facts are hard to ignore. Even though we know that lower

> > BMIs are associated with less diabetes and cancer, and that lower

> BMIs

> > require fewer calories, it was not the low BMI people who lived the

> > longest. Go figure.

> >

> > Tony Zamora

> >

> >

> >

> > Calle EE, Thun MJ, Petrelli JM, C, Heath CW Jr. Body-mass

> > index and mortality in a prospective cohort of U.S. adults. N Engl J

> > Med. 1999 Oct 7;341(15):1097-105. PMID: 10511607

> >

> > In a prospective study of more than 1 million adults in the United

> > States (457,785 men and 588,369 women), 201,622 deaths occurred

> during

> > 14 years of follow-up.

> > In healthy people who had never smoked, the nadir of the curve for

> > body-mass index and mortality was found at a body-mass index of 23.5

> > to 24.9 in men and 22.0 to 23.4 in women.

> >

[Guest guest]

Hi Tony:

I very much agree with your first paragraph. When I said in my first

response to you that if the subjects had instead been on 30% CR

**almost all** of them would have lived a lot longer, I

specified " almost all " for the very reason that I recognized some

would not benefit. As one clear example, those starting out slim

because of intestinal absorption problems, will already - before CR -

be deficient some key nutrients. So exacerbating their nutrient

deficiencies by further restriction, would not likely be of benefit

to *their* health or longevity. And there may be others who would

not benefit, for other specific reasons. But I submit it certainly

would be of benefit to the vast majority.

As regards your view that perhaps lifespan can be maximized

(optimized?) by just gradually reducing calories to prevent weight

gain with age, I do not doubt that preventing weight gain with age

will confer some benefit. But let me ask you this: are you aware of

any research study (preferably in a mammalian species) which

reasonably clearly demonstrates the longevity gains from such an

approach to be even remotely close to those of 40% CR?

I am not aware of any study which even tried to compare the health

benefits of such a strategy with 40% CR ....... let alone one that

had results indicating benefits anywhere close to those of 40% CR.

When someone posts a reference to a study which appears to

demonstrate this - hopefully confirmed by others - then I will

certainly sit up and pay attention to this possibility. But in the

meantime I will continue to pursue a strategy modelled on the animal

experiments which have shown the greatest longevity benefits to

date. This means: 30% or more CR; while maintaining full nutrition;

avoiding foods I believe to be hazardous; and emphasizing foods there

is reason to suspect may be especially healthy.

And I plan to change my strategy as new evidence emerges that I find

persuasive.

Rodney.

> > >

> > > The notion of having as much fat as possible while eating as

little

> > as

> > > possible for longevity seems contradictory. Dr. Walford

thought

> > that

> > > you needed to have a BMI of less than 20 (BT120YD, p.228) to

live

> > > long. However, the following study of over 1 million people

found

> > > that a BMI of around 23 was associated with the greatest

longevity

> > > (PMID: 10511607). Needless to say, when this paper was

discussed in

> > > the CRS group last year, there was much skepticism. Even

> > > Delaney expressed his doubts.

> > >

> > > However, facts are hard to ignore. Even though we know that

lower

> > > BMIs are associated with less diabetes and cancer, and that

lower

> > BMIs

> > > require fewer calories, it was not the low BMI people who lived

the

> > > longest. Go figure.

> > >

> > > Tony Zamora

> > >

> > >

> > >

> > > Calle EE, Thun MJ, Petrelli JM, C, Heath CW Jr. Body-

mass

> > > index and mortality in a prospective cohort of U.S. adults. N

Engl J

> > > Med. 1999 Oct 7;341(15):1097-105. PMID: 10511607

> > >

> > > In a prospective study of more than 1 million adults in the

United

> > > States (457,785 men and 588,369 women), 201,622 deaths occurred

> > during

> > > 14 years of follow-up.

> > > In healthy people who had never smoked, the nadir of the curve

for

> > > body-mass index and mortality was found at a body-mass index of

23.5

> > > to 24.9 in men and 22.0 to 23.4 in women.

> > >

>