Re: another body fat study

[Guest guest]

Hello all,

An important distinction is that these studies are not

looking at specific populations. Some people are scrawny

because of other conditions or habits (anorexia, excessive

exercise, digestive problems, illness, etc...) and some

are obese for others. My point is, these studies are not

accounting for a populations with a lower BMI but still on

a nutritionally complete diet. I don't think we should

discount their point (ie: that 'abnormal' BMIs can point

to potential associations with higher mortality rates),

but we're not really engaged in the normal activities they

are taking under consideration.

After all, a mouse population that is calorically

restricted, but not nutrionally viable, will die... CRON

is a specific intervention and we don't have much real

data on human yet, and we're not likely to for quite some

time.

Cheers,

[Guest guest]

I don't doubt the data or the relationship. What I sincerely doubt is that it represents US. High body fat is maybe bad amongst uneducated "pigs" who eat a LOT more than I do, eg. And the wrong foods probably.

Then there's a VERY large question about what action do we take with knowledge of that data? Losing weight is not for amateurs.

Wouldn't you say there's a diff between a person who eats 1800 kcals and weighs 178# versus one who eats 3000 kcals and weighs the same? One can be waist 38" the other 46".

I think the emphasis should be on calories, not BMI, not BF%, not appearance, and not shoe size either.

Regards.

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

From: Diane Walter

Sent: Tuesday, June 21, 2005 11:56 AM

Subject: [ ] another body fat study

This was a limited 5.8 year study for people between the ages of50-64. Same conclusions, though. High body fat is bad, and so is lowfat-free mass.Mortality and body fat and fat-free massNutrition Research Newsletter, Sept, 2004 The health effects of obesity have been thoroughly studied using BMIas a measure of adiposity and all-cause mortality as the endpoint.Many studies have identified U- or J-shaped associations between BMIand mortality. It has been hypothesized that all-cause mortality isincreased at high levels of body fat mass and at low levels offat-free mass (FFM), creating this U-shaped association. Previousresearch has investigated this using total body potassium counting ormeasurements of skinfold thickness to determine lean and fat mass.However, a new prospective study measured body composition bybioelectrical impedance to investigate whether the association betweenBMI and all-cause mortality could be disentangled into opposite effectof body fat and FFM.Data was used from 27,178 men and 29,875 women included in the Danishfollow-up study, Diet, Cancer and Health. The subjects were 50 to 64years old. All anthropometric data were collected at two study clinicsin Aarhus and Copenhagen. Body composition was assessed bybioelectrical impedance. All-cause mortality was the endpoint in thestudy with the median follow-up period being 5.8 yr.Men and women showed similar J-shaped associations between body fatmass index and mortality after adjusting for FFM and smoking. Themortality rate ratios in the upper part of body fat mass were 1.12 perkg/[m.sup.2] in men and 1.06 per kg/[m.sup.2] in women. ReversedJ-shaped associations were found between FFM index and mortality witha tendency to level off for high values of FFM. There were no effectmodifications of age, time since baseline examination, smoking orhospital contacts.The results demonstrated that the U-shaped association between BMI andall-cause mortality reflects the combination of a J-shaped associationbetween body fat mass index (BFMI) and mortality and a reverseJ-shaped association between FFM index (FFMI) and mortality. Both highbody fat and low FFM are independent predictors of all-causemortality. However, caution should be taken when generalizing thesefindings since the age range was limited to 50 to 64 years old andthere was a relatively short follow-up period.Janne Bigaard, Kirsten Frederiksen, Anne Tjonneland, et al., Body fatand fat-free mass and all-cause mortality, Obesity Research 12(7):1042-1054 (July 2004) [Address correspondence to Janne Bigaard,Institute of Cancer Epidemiology, The Danish Cancer Center,Strandboulevarden 49, DK-2100 Copenhagen, Denmark. E-mail:janne@...]

[Guest guest]

The suggestion is that higher BMI individuals are at risk due to too much BF

and lower BMI individuals are at risk because of too low fat free mass.

While there is little debate that too much BF is bad, AFAIK this list is not about how

to be heavy and healthy. It seems our interest should be in the focus on lower BMI.

This discussion of FFM being important seems at odds with our regular citation of %BF

as the possible risk factor and a lower limit red line.

Of course extreme low FFM may just be a marker for wasting from some other disease

state and not be a useful independent factor.

JR

-----Original Message-----From: [mailto: ]On Behalf Of jwwrightSent: Tuesday, June 21, 2005 12:45 PM Subject: Re: [ ] another body fat study

I don't doubt the data or the relationship. What I sincerely doubt is that it represents US. High body fat is maybe bad amongst uneducated "pigs" who eat a LOT more than I do, eg. And the wrong foods probably.

Then there's a VERY large question about what action do we take with knowledge of that data? Losing weight is not for amateurs.

Wouldn't you say there's a diff between a person who eats 1800 kcals and weighs 178# versus one who eats 3000 kcals and weighs the same? One can be waist 38" the other 46".

I think the emphasis should be on calories, not BMI, not BF%, not appearance, and not shoe size either.

Regards.

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

From: Diane Walter

Sent: Tuesday, June 21, 2005 11:56 AM

Subject: [ ] another body fat study

This was a limited 5.8 year study for people between the ages of50-64. Same conclusions, though. High body fat is bad, and so is lowfat-free mass.Mortality and body fat and fat-free massNutrition Research Newsletter, Sept, 2004 The health effects of obesity have been thoroughly studied using BMIas a measure of adiposity and all-cause mortality as the endpoint.Many studies have identified U- or J-shaped associations between BMIand mortality. It has been hypothesized that all-cause mortality isincreased at high levels of body fat mass and at low levels offat-free mass (FFM), creating this U-shaped association. Previousresearch has investigated this using total body potassium counting ormeasurements of skinfold thickness to determine lean and fat mass.However, a new prospective study measured body composition bybioelectrical impedance to investigate whether the association betweenBMI and all-cause mortality could be disentangled into opposite effectof body fat and FFM.Data was used from 27,178 men and 29,875 women included in the Danishfollow-up study, Diet, Cancer and Health. The subjects were 50 to 64years old. All anthropometric data were collected at two study clinicsin Aarhus and Copenhagen. Body composition was assessed bybioelectrical impedance. All-cause mortality was the endpoint in thestudy with the median follow-up period being 5.8 yr.Men and women showed similar J-shaped associations between body fatmass index and mortality after adjusting for FFM and smoking. Themortality rate ratios in the upper part of body fat mass were 1.12 perkg/[m.sup.2] in men and 1.06 per kg/[m.sup.2] in women. ReversedJ-shaped associations were found between FFM index and mortality witha tendency to level off for high values of FFM. There were no effectmodifications of age, time since baseline examination, smoking orhospital contacts.The results demonstrated that the U-shaped association between BMI andall-cause mortality reflects the combination of a J-shaped associationbetween body fat mass index (BFMI) and mortality and a reverseJ-shaped association between FFM index (FFMI) and mortality. Both highbody fat and low FFM are independent predictors of all-causemortality. However, caution should be taken when generalizing thesefindings since the age range was limited to 50 to 64 years old andthere was a relatively short follow-up period.Janne Bigaard, Kirsten Frederiksen, Anne Tjonneland, et al., Body fatand fat-free mass and all-cause mortality, Obesity Research 12(7):1042-1054 (July 2004) [Address correspondence to Janne Bigaard,Institute of Cancer Epidemiology, The Danish Cancer Center,Strandboulevarden 49, DK-2100 Copenhagen, Denmark. E-mail:janne@...]

[Guest guest]

Well said, Jim. We've said all along that the field of nutrition is

nascent-- we just don't know what a healthy lower limit to BMI/BF is

for humans with a nutritionally correct diet. And these studies are

statistical as well. Having a very low BMI (or a very high one) may

not (or may) kill you. We just don't know yet. I think still these

studies point to the need for caution.

Diane

> Hello all,

>

> An important distinction is that these studies are not

> looking at specific populations. Some people are scrawny

> because of other conditions or habits (anorexia, excessive

> exercise, digestive problems, illness, etc...) and some

> are obese for others. My point is, these studies are not

> accounting for a populations with a lower BMI but still on

> a nutritionally complete diet. I don't think we should

> discount their point (ie: that 'abnormal' BMIs can point

> to potential associations with higher mortality rates),

> but we're not really engaged in the normal activities they

> are taking under consideration.

>

> After all, a mouse population that is calorically

> restricted, but not nutrionally viable, will die... CRON

> is a specific intervention and we don't have much real

> data on human yet, and we're not likely to for quite some

> time.

>

> Cheers,

>

[Guest guest]

JR said:

" While there is little debate that too much BF is bad, AFAIK this

list is not about how to be heavy and healthy. It seems our interest

should be in the focus on lower BMI. "

However, JW's Message 19279 has a chart showing that BMI from 20 to

<22 was associated with the minimum number of deaths. This is

consistent with one of the spreadsheets that we have in our files.

(CSPI_plots_of_BMI_vs_disease_risk.xls)

If the purpose of CR is to achieve longevity, rather than just a lower

BMI, I think that we have to pay attention to the numbers. The

empirical evidence seems to be telling us that the " sweet zone " for

longevity (or minimum risk of death) is around BMI 21 (plus or minus

1).

Extra credit research: What is the BMI of typical centenarians?

Tony

[Guest guest]

>>>Extra credit research: What is the BMI of typical centenarians?

http://www.jacn.org/cgi/content/full/18/4/358

http://www.jacn.org/content/vol18/issue4/images/large/cq0390552001.jpeg

Okinawan elders are lean, with average body mass index (BMI) that ranges

from 18 to 22

A Comparison of Anthropometry, Biochemical Variables and Plasma Amino

Acids among Centenarians, Elderly and Young Subjects . Journal of the

American College of Nutrition, Vol. 18, No. 4, 358-365 (1999)

From another study...

http://www.actabp.pl/pdf/2_2000/281-292s.pdf

Mean 23.15

Range 15.1 - 33.2

[Guest guest]

As complex as the nutrition/health problem is, I'm not sure we aren't interested in heavy and healthy. They may not live as long but I don't know that either as a general rule. The healthy ones may be those 1's in the low end of the span of risk factor.

I think I should focus on caloric intake not BMI, BF% or any other conventional measure determined from measuring folks who are not CRONies.

The only reason we look at those data is because we don't have the same for CRONies yet. If I can get to the "ideals", whatever they are, all well and good.

We need "biometrics" that show CRONies are at a lower biological age.

Regards.

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

From:

Sent: Tuesday, June 21, 2005 2:06 PM

Subject: RE: [ ] another body fat study

The suggestion is that higher BMI individuals are at risk due to too much BF

and lower BMI individuals are at risk because of too low fat free mass.

While there is little debate that too much BF is bad, AFAIK this list is not about how

to be heavy and healthy. It seems our interest should be in the focus on lower BMI.

This discussion of FFM being important seems at odds with our regular citation of %BF

as the possible risk factor and a lower limit red line.

Of course extreme low FFM may just be a marker for wasting from some other disease

state and not be a useful independent factor.

JR

-----Original Message-----From: [mailto: ]On Behalf Of jwwrightSent: Tuesday, June 21, 2005 12:45 PM Subject: Re: [ ] another body fat study

I don't doubt the data or the relationship. What I sincerely doubt is that it represents US. High body fat is maybe bad amongst uneducated "pigs" who eat a LOT more than I do, eg. And the wrong foods probably.

Then there's a VERY large question about what action do we take with knowledge of that data? Losing weight is not for amateurs.

Wouldn't you say there's a diff between a person who eats 1800 kcals and weighs 178# versus one who eats 3000 kcals and weighs the same? One can be waist 38" the other 46".

I think the emphasis should be on calories, not BMI, not BF%, not appearance, and not shoe size either.

Regards.

[Guest guest]

Hi folks:

This is an interesting conclusion (from Jeff's first link) when you

consider it pre-dates the Partridge fruit fly study by five years

(the use of capitalization is mine):

" The present results may indicate that the centenarians had poor

nutritional status, which may be due to their decreased metabolism

and the possibility that ***only*** SHORT, SLENDER individuals with

LOW LIPIDS, PROTEIN and essential AMINO ACIDS are those that tend to

survive to be centenarians. "

Low fat and protein, again, in addition to being slender.

Rodney.

--- In , " Jeff Novick " <jnovick@p...>

wrote:

>

> >>>Extra credit research: What is the BMI of typical centenarians?

> http://www.jacn.org/cgi/content/full/18/4/358

>

http://www.jacn.org/content/vol18/issue4/images/large/cq0390552001.jpe

g

>

> Okinawan elders are lean, with average body mass index (BMI) that

ranges

> from 18 to 22

>

> A Comparison of Anthropometry, Biochemical Variables and Plasma

Amino

> Acids among Centenarians, Elderly and Young Subjects . Journal of

the

> American College of Nutrition, Vol. 18, No. 4, 358-365 (1999)

>

> From another study...

>

> http://www.actabp.pl/pdf/2_2000/281-292s.pdf

>

> Mean 23.15

> Range 15.1 - 33.2