Re: Kcal vs. protein (was: [Re: Which calories?])

[Guest guest]

my main concern is what would be the macro-nutrient proportions that would be best for our health now

i'm not so concerned what we ate when we lived in caves (before or after fire)

i find the experiments below interesting and they provide hope with regards to cr

but what i'm trying to understand is with regards to human life extension how would these experiments translate

this is my bottle neck:

if one would perform a cr experiment on both a carnivore (lion for example) and on a herbivore (cow for example)

i don't see how macro-nutrients would even play a part in the experiment

the carnivore would be given a high % protein and fat diet and the herbivore would be given a high % carb diet

believing that humans are omnivores, i understand that its a little more complicated than that

i just don't see (with a great certainty) how i could base my

macro-nutrient proportions on another animal who may or may not be

genetically predispose to a certain " diet "

thanks for the response below,

i just trying to get a foot hold on cr

On 9/29/05, Rodney <perspect1111@...> wrote:

Hi J^3:

Yes. Although, by the nature of the thing, high carb means low

something else, and it may be the low something else that is the key

issue - i.e. is it low fat? Or low protein? Or either very low fat

or very low protein, that extends maximum lifespan? The

Mair/Partridge study currently underway should, I hope, provide a

clear answer to that question for flies.

I have no good advice as to the nature of the human " natural diet " .

When you ask that question do you mean what did we eat when we lived

in caves? And if so then are you talking before we discovered fire,

or after? Or are you asking what macronutrient proportions would

provide the best health? They may not be the same, of course.

In addition, what maximized lifespan back then very likely is not

what would maximize our lifespans today. And what maximized it would

also vary depending on the climate we happened to be living in.

Those of us in Africa at the time would have had very different needs

from those trying to cope with the ice age.

Rodney.

> >

> > Hi Willie:

> >

> > This part is interesting:

> >

> > " ......... but the calorie restriction did not produce as much

life

> > extension when the diets had a high fat or high protein content

as it

> > did when the diet had a very high proportion of carbohydrates "

> >

> > because it seems to be consistent with the fruit fly study where

> > restriction of carbohydrates didn't make much difference.

> >

> > But is it the fat or the protein that matters?

> >

> > Rodney.

> >

> > --- In , " " <wmbragg@h...>

wrote:

> > > Hi all,

> > >

> > > Here you have a reference that points just in another direction

> > > regarding the issue of calories from carbs or protein. Of

course,

> > > one have to have in mind this strain of mice had a renal

disease,

> > > but it's worth reading it

> > >

> > > http://www.pnas.org/cgi/reprint/83/15/5659

> > >

> > > Take a look at this extract:

> > >

> > > " It was also of interest that the diet that promoted the very

> > > longest life and the greatest increase in maximum life span in

> > > these relatively short-lived mice was the diet of very high

> > > carbohydrate, low fat, normal protein composition. However,

> > > this diet exhibited the greatly beneficial effect only when

> > > fed as a calorie-restricted diet. The diets higher in fat and

> > > higher in protein permitted the increasing of longevity and life

> > > span when fed in restricted amounts, but the calorie restriction

> > > did not produce as much life extension when the diets

> > > had a high fat or high protein content as it did when the diet

> > > had a very high proportion of carbohydrates. "

> > >

> > > Cheers.

> > > Willie.

> > >

> > > Hi Willie:

> > >

> > >From the same authors:

> > >

> > > " In the group of mice with 60% intake of a carbohydrate-free

(i.e.,

> > >high fat) diet, mean longevity was doubled as compared to that

of ad

> > >libitum-fed mice. However, when the nonprotein energy was

supplied by

> > >carbohydrate (sucrose and glycerol) the mean longevity was three

> > >times that of the ad libitum-fed groups ...................

> > > clearly, although energy intake restriction provides significant

> > >influence on longevity, very high fat diets do not give the same

> > >protection as do high carbohydrate diets. " PMID: 3598724.

> > >

> > >And,

> > >

> > > " .......... In mice consuming a restricted energy intake of a

diet

> > > providing identical amounts of protein to those consumed by ad

> > > libitum-fed mice, whether the protein intake was very high or

normal,

> > > longevity was equally greatly prolonged. " PMID: 3598725.

> > >

> > > Based on this one would be tempted to conclude, as Pritikin

did a

> > > long time ago, that it is FAT restriction that is critical. But

> > > these are old studies and, as Willie noted, these are a very

specific

> > > type of mice. So who knows if the results will be found apply to

> > > humans. But they do seem to agree with Mair, Partridge & Co that

> > > carbohydrate is not the really key component, in mice as well as

> > > fruit flies. And these results suggest that Mair and Partridge

may

> > > right now be in the midst of discovering that fat is much more

> > > important than protein or carbs. We will see. But either way it

> > > will have interesting ramifications.

> > >

> > > Rodney.

> >

> >

> >