After the above, I just wonder,What's a safe upper bound of proteins intake. According to NIH it's twice the RDA, that is 1.5 g/kg of ideal bodyweight.

This is the WHO, 2002 official source:

http://apps.who.int/iris/bitstream/...TRS_935_eng.pdf

Chapter 3 has the statistical (lognormal) distribution of protein requirements (expressed in mg nitrogen/kg bodyweight). Since the distribution si lognormal, the NIH values are slightly larger, 0.65= average and 0.8 =97.5 percentile.

0.8 g/kg= safe daily intake.

A lognormal distribution also means that very low number of people can have inordinately high requirements.
Chapter 3 also contains other interesting statistical data.

Sorry for temporarily hijacking this thread, I'm almost over then going to hit the sack. any gross mistakes in the following reasonings are due to sleepyness!!

The statistical aspect would be a plausible criticism to Dr. Rosedale's affirmations. Since there is such an inherent variability in protein requirements across individuals, the mTOR optimum is inevitably going to mirror such variability.
Hence, We may reformulate dr. Rosedale's words as follows:

IF we eat more than the safe protein requirement of 0.8 gr/kg, then we'll likely upregulate mTOR since that's definitely an abundance of proteins for most people.

If we eat less than the safe protein requirement of 0.8 gr/kg, we still might have an upregulated mTOR, if our specific requirement is located on the low percentiles of the statistical distribution of protein requirements.

If we eat the average protein requirement= 0.65 gr/kg, then it is not too much likely that mTOR will be upregulated, unless we are in the very low percentiles, that is, unless we absorb proteins like a sponge.

Deirdra - I'm with you. I am beginning to wonder if this focus on longevity is missing the point, a prioritizing of quantity over quality. I'm going to have to do more thinking on this to work out exactly what I mean but I'm thinking that there may be some confusion between attaining maximum longevity and attaining optimal health.

Jean

Use this,
http://keto-calculator.ankerl.com/

Click on the + link after "if you put your muscles under a lot of new stress or with a large caloric deficit to prevent muscle loss. " to discover the science behind it.

Correct me if I'm wrong. But all the data that is being used by Rosedale, et al, are on lab animals. For good reason. Protein needs in humans are NOT identical to protein needs of animals in the lab, where the content of their diets is strictly controlled.

Of course, there is always this confounding factor: unless the nutrient being studied is consumed in isolation, there is no way to determine if the effects being observed would differ in the absence of another nutrient. Protein + fat + carbs = what effect? Protein + carbs and very low fat = what effect?

And protein + fat + very low carbs = an effect that most of us are familiar with, at least in the measures used to determine present health, as opposed to longevity.

One of the newer pieces of data that's been bouncing around is that, for people over 60, it appears that there is some protective angle to having a slightly higher BMI, between 26 and 27. The idea seems to be that, should an older person be injured, or suffer a long term disease, that a little more body mass can offer a buffer against the ravages of disease and injury.

Expecting people to be rail thin, especially women, affects not only their general health, but for younger women, will lead to amenorrhea, and loss of bone mass, with resulting crippling.

NOT my idea of a good life, at all.

Posted today by the Real Meal Revolution:

http://realmealrevolution.com/real-...g/protein-power

This is Tim Noakes' organization.

Jean

Thanks, Jean. If only the outliers recommend tiny amounts of protein, and they are basing it on, primarily, rodent studies, then I feel perfectly comfortable relying on what I was used to: the 1 gram per kilo of ideal body weight, up to 1.5, for body builders.

For me, that's between 65.77 (make it 66) grams and 99 grams/day.

Which, amazingly enough, is what I average, and keeps me healthy.

I do have a question for those who advocate Rosedale's recommendations. The claim is that this can prolong life. To what from what?

I ask because using any of the length of life projection quizzes available, I come up with somewhere in the mid 90's. Obviously, there are outliers, and, also obviously, I could get hit by a car tomorrow and die. But I'm not convinced that I necessarily NEED to live much past 95, you know?

Any grandkids who are yet to be born will be full fledged adults by then, my children themselves will be into their 60's.

If one has a brilliant mind, and can continue to use it to make new discoveries well into their 11th and 12th decades, then, by all means, try to live that long.

Me? I'm pretty smart, but not brilliant. I'm usually kind, but not a great philanthropist. And while I can come up with pretty good LC recipes, I'm not hugely creative. My goals are more modest. I want to live well till I die, and share love and happiness with those around me.

I don't need to live to be 117 to do that, you know?

Another thing to look at is what is meant by longevity in these studies. If maximal longevity--we might be looking at winning a sort of longevity lottery, the intervention that increases the maximum lifespan may not increase the average or the median lifespan.

Not every species of mouse experiences an increase in longevity on calorie restriction. Or rather--not every species of mouse experienced an increase in longevity when the particular chow used in the study they were involved in was restricted.

We had an earlier discussion on the topic of protein restriction here.

http://forum.lowcarber.org/showthread.php?t=467837

Aspect #1: the lab studies on calorie restriction are not studies on proteins requirements, rather comparative analyses between a calorie-restricted group and a control group of the same species. Control groups tend to live longer.

Aspect#2: confounding factor. yes, I too was reasoning along the same line, maybe more carbs mean less proteins requirements. But Rosedale says something counterintuitive, that is, he specifically relates to old people, in hi-carbers the body burns muscle and bone tissue when there is no sugar available, so protein requirement is higher to make up for this loss. Basically, accordign to such example, low carbers should need less proteins than hi-carbers, all otehr things being equal of course.

That's an interesting article, in that we recognize how so much different the various schools of thought can be in suggesting an optimum requirement of proteins.

MickiSue, I really don't know. Dr Rosedale speaks about a 200 years potential, which sounds really otpimistic. Also, we cannot give numbers, we should speak in terms of probability.
That is, by downregulating the mTOR pathway we are allegedly less likely to die by cancer and degenerative disease, and this improves the likelyhood to live longer. This of course ruling out accidents, and Dr. Attia speaks about the latter as well. Manipulation of nutrient sensing pathways like mTOR is only one aspect though, there are others such keeping insulin and IGF low, keepign glycation low, keepign stress low, sleeping enough, taking appropriate hormones and drugs.

This is all so highly speculative. Perhaps my favorite book title is "Don't Believe Everything you Think". Rosedale is speculating and that's fine but I really don't think he is ready for prime time. And then there are the other nagging questions: Longevity for what purpose? Longevity at what cost? Will we really get both quality and quantity improvements? And is this all really perhaps more motivated by the fear of death? What I like about the lchf diet I am now eating is that I have vastly improved the quality of my life. I am hoping that it will increase my longevity but as i said somewhere else however old I am when I die I will not know if I lived longer than I otherwise would have, so I'm willing to stay focused on quality now and hope the quality lasts as long as I do. And even if it does or doesn't I hope that I die peacefully with no regrets. I got a bit way laid here thinking about the holy grail of longevity but I really don't want that to be my primary goal.

Jean

I read the discussion, but the impression here is that Rosedale read all the literature about lab animals longevity and inferred that most papers gave evidence to the low proteins=longer lifespan hypothesis.a
Pls note that Rosedale does advocate eating fats instead of carbs. Actually, he describes how an abundance of carbs is also detrimental to longevity.
Apparently though, dietary aminoacids control lifespan more than carbs.
Of course, restricting both proteins and carbs would be the best solution.

Even at this point, I have not a clear idea on how much protein is needed to activate the mTOR pathway (there is also some difference in liver mTOR and muscle mTOR and in mTORC1 and mTORC2).

By pure logic, if an abundance of aminoacids is sensed by mTOR as a condition which leads to growth & reproduction mode, we should define the value for abundance. Also, is there an intermediate range (enough proteins, maybe a little more than needed, but not many more) where mTOR is not activated? Probably so.

Also, if the WHO, 2002 nitrogen balance studies are correct, protein requirement in humans is a random variable with a significant variability. This means that we cannot by a single number determine if the mTOR pathway has been upregulated. Rosedale's value seem to mirror the WHO, 2002 Reccomended values, but 0.8 gr/kg si a 97.5 percentile in the WHO study, so in a significant part of the population that would be a value higher than the basic requirement. Is mTOR going to construe that as 'abundance'?

Again, and I should read more in detail the WHO study, were the requirements calculated on an actual or ideal bodyweight? That would change things increasing the requirements if ideal bodyweight was not considered and a non negligible number of individuals was overweight.

I have this terrible hunch that we should individually determine our protein optimum, and that's not so easy. Should we eat less and less until we loose muscle mass and then estimate our zero-balance value? That would be the threshold for mTOR activation. But how do we measure muscle mass? Should we measure nitrogen in stools and urine until we take the balance to negative just to determine the mTOR optimum? A zero or slighlty positive nitrogen balance would not be probably a signal of abundance.

This entire discussion makes me think of a science fiction book I read years ago. Enough years that I can remember neither the author nor the title--I was reading a LOT of SF, back then.

But the story was about post interstellar contact Earth. And the humans were growing smaller and weaker, by the generation, following the diet requirements that they were given, supposedly for optimal use of resources and nutrition, by the aliens.

I remember pretty much nothing else of the plot but this: it turns out, in the end, that the "optimal" nutritional intake was posited on this: the aliens believed that humans had misused their ability to outthink the rest of the species on the planet, and needed to be eliminated. But, not being warlike, their solution was to make humans, over time, so weak and powerless (malnutrition, of course, affects neural processing, just like the other functions of the body) that they would slowly fade away as a factor in the ecosystem of this planet.

Dr. Rosedale's recommendations, AND his claim that humans can live to be 200 by eating too little protein, makes me think of the "kindly" aliens in that story.