27 replies to this topic

[corb]

I've been meaning to start posting research that's based on humans and goes AGAINST mice proven life extension research, and I think I'll be doing it a lot from now on.

 

Cyclist consume ludicrous amounts of calories. Up to 6000 every day for years.

So even though I myself agree that a lean "healthy" diet, most probably has health benefits, I'm very skeptical it does anything for your lifespan as illustrated in this paper:

 

 

http://www.ncbi.nlm....pubmed/21618162

 

Increased average longevity among the "Tour de France" cyclists.

Sanchis-Gomar F¹, Olaso-Gonzalez G, Corella D, Gomez-Cabrera MC, Vina J.

Author information

Abstract

It is widely held among the general population and even among health professionals that moderate exercise is a healthy practice but long term high intensity exercise is not. The specific amount of physical activity necessary for good health remains unclear. To date, longevity studies of elite athletes have been relatively sparse and the results are somewhat conflicting. The Tour de France is among the most gruelling sport events in the world, during which highly trained professional cyclists undertake high intensity exercise for a full 3 weeks. Consequently we set out to determine the longevity of the participants in the Tour de France, compared with that of the general population. We studied the longevity of 834 cyclists from France (n=465), Italy (n=196) and Belgium (n=173) who rode the Tour de France between the years 1930 and 1964. Dates of birth and death of the cyclists were obtained on December 31 (st) 2007. We calculated the percentage of survivors for each age and compared them with the values for the pooled general population of France, Italy and Belgium for the appropriate age cohorts. We found a very significant increase in average longevity (17%) of the cyclists when compared with the general population. The age at which 50% of the general population died was 73.5 vs. 81.5 years in Tour de France participants. Our major finding is that repeated very intense exercise prolongs life span in well trained practitioners. Our findings underpin the importance of exercising without the fear that becoming exhausted might be bad for one's health.

[Mind]

This is complicated, as Reason points out here: https://www.fightagi...live-longer.php

 

Elite athletes probably have better genetics, and might be somewhat pre-destined to live longer, no matter their diet, calories, exercise.

 

 

[corb]

 

We found a very significant increase in average longevity (17%) of the cyclists when compared with the general population.

Not all of them had perfect genetics don't kid yourself about that, those were cyclists from the time when getting into the sport was much easier. The quote on top to drive the point through that they lived more ON AVERAGE.

 

But let's disregard that for a second. And look at a paper that goes into WHY dietary restriction works in mice and probably will not in humans:

 

 

Abstract

[...] We predict that, in view of the different metabolic stability of the two systems, caloric restriction will have no effect on the maximum life-span potential of humans, and a relatively minor effect on the mean life span of nonobese populations. This article thus points to certain intrinsic limitations in the use of mouse models in elucidating the aging process in humans. We furthermore contend the view that these limitations can be mitigated by considering the metabolic stability of the two species.

 

http://www.ncbi.nlm....pubmed/21618162

 

It goes into some detail explaining the process. It's quite an old paper.
In compliance with this paper rhesus monkeys in a CR trial lived a normal life span (I'll look for the paper later) as theorized by the paper above.

 

Now I've found a trial that indeed proves that CR has benefits for the obese, again in compliance with the paper, I posted it in the dietary mimetic thread as well. http://www.plosone.o...al.pone.0047079

Also it alludes that CR has no observable benefits if any for people of normal bmi.

 

I'm yet to find a human trial proving CR works in humans, hopefully with the mimetic soon to be sold we'll be able to get some concrete results by ... next decade maybe. Even though CR has been a thing for a decade already, so if it works I think we would know by now.

I'll keep posting papers when I find them.

Edited by corb, 24 August 2014 - 06:32 PM.

[corb]

I can't edit my other post anymore, this is the paper on rhesus monkey longevity I was talking about.

 

 We report here that a CR regimen implemented in young and older age rhesus monkeys at the National Institute on Aging (NIA) has not improved survival outcomes.

 

http://www.ncbi.nlm....pubmed/22932268

Unfortunately it's not a free paper.

 

It does say there were observed health benefits in the abstract, but we have to bare in mind those are LAB ANIMALS - the equivalent of couch potatoes for humans.

 

[Gerrans]

For me the delusion of calorie restriction is the idea that by keeping your body below a normal weight you will live longer. The evidence seems to show that people in the underweight BMI category live shorter lives on average. Even though it could be argued that this is because the underweight cohort includes more people with lifelong health issues, metabolic issues, or drug and smoking habits, I would not want to take the risk of lowering my weight into the underweight category. It seems to me common sense that underweight people would have fewer resources to cope with stresses such as a hospitalisation, particularly should they be unable to eat properly for a while.

 

I keep my weight in the lower half of the normal weight BMI category, and I would be surprised if going twenty pounds lighter would benefit my health. I already have to be careful to avoid onset of cold extremities and low blood pressure.

 

I am 5'10", 150lb, 59 years old, in good health.

Edited by Gerrans, 25 August 2014 - 11:34 AM.

[scottknl]

For me the delusion of calorie restriction is the idea that by keeping your body below a normal weight you will live longer. The evidence seems to show that people in the underweight BMI category live shorter lives on average. Even though it could be argued that this is because the underweight cohort includes more people with lifelong health issues, metabolic issues, or drug and smoking habits, I would not want to take the risk of lowering my weight into the underweight category. It seems to me common sense that underweight people would have fewer resources to cope with stresses such as a hospitalisation, particularly should they be unable to eat properly for a while.

 

I keep my weight in the lower half of the normal weight BMI category, and I would be surprised if going twenty pounds lighter would benefit my health. I already have to be careful to avoid onset of cold extremities and low blood pressure.

 

I am 5'10", 150lb, 59 years old, in good health.

 

Hmm...very interesting.  You completely ignore the studies on CR volunteers and their excellent lipids and other numbers when you make these conclusions.  The seventh day adventist trials show us that basic lifestyle changes can make a difference of 8 - 9 years in lifespan.  One should expect the CR to do somewhat better than that since their lifestyle changes are similar, but with all the nutrition and fewer calories.

 

http://www.ncbi.nlm....cles/PMC404101/  - CR provide 40% better IMT measurements vs control.

 

http://www.ncbi.nlm....pubmed/24606898 -  Respondents aged 50-65 reporting high protein intake had a 75% increase in overall mortality and a 4-fold increase in cancer death risk during the following 18 years. These associations were either abolished or attenuated if the proteins were plant derived. Conversely, high protein intake was associated with reduced cancer and overall mortality in respondents over 65, but a 5-fold increase in diabetes mortality across all ages

 

http://www.ncbi.nlm....pubmed/23912304 - We show that treatment of cultured cells with CR sera caused increased expression of stress-response genes and enhanced tolerance to oxidants. Cells cultured in serum from CR individuals showed a 30% increase in resistance to H2O2 damage. Consistently, SOD2 and GPX1 mRNA, two key endogenous antioxidant enzymes, were increased by 2 and 2.5 folds respectively in cells cultured with CR sera. These cellular and molecular adaptations mirror some of the key effects of CR in animals, and further suggest that circulating factors contribute to the CR-mediated protection against oxidative stress and stress-response in humans as well.

 

http://www.ncbi.nlm....pubmed/21841020 - Taken together, research shows that CR has numerous beneficial effects on the aging cardiovascular system, some of which are likely related to reductions in inflammation and oxidative stress. In the vasculature, CR appears to protect against endothelial dysfunction and arterial stiffness and attenuates atherogenesis by improving several cardiometabolic risk factors. In the heart, CR attenuates age-related changes in the myocardium (i.e., CR protects against fibrosis, reduces cardiomyocyte apoptosis, prevents myosin isoform shifts, etc.) and preserves or improves left ventricular diastolic function. These effects, in combination with other benefits of CR, such as protection against obesity, diabetes, hypertension, and cancer, suggest that CR may have a major beneficial effect on health span, life span, and quality of life in humans.

 

There are more studies than this, of course.

 

However, I do agree with your approach of maintaining BMI near the low end of the normal range.

[scottknl]

I can't edit my other post anymore, this is the paper on rhesus monkey longevity I was talking about.

 

 We report here that a CR regimen implemented in young and older age rhesus monkeys at the National Institute on Aging (NIA) has not improved survival outcomes.

 

http://www.ncbi.nlm....pubmed/22932268

Unfortunately it's not a free paper.

 

It does say there were observed health benefits in the abstract, but we have to bare in mind those are LAB ANIMALS - the equivalent of couch potatoes for humans.

 

 

 

 

How Much Should We Weigh for a Long and Healthy Life Span? The Need to Reconcile Caloric Restriction versus Longevity with Body Mass Index versus Mortality Data.  Provides the above graph and discussion.  It seems to get to the main point about the differences in the WNPRC and NIA studies.  It seems to be suggesting that the WNPRC CR group hit the sweet spot, but that the result was exaggerated by the obese control group.

[corb]

Unfortunately none of the papers you provide show a concrete proof of lifespan benefits.
As I stated in my original post

 

So even though I myself agree that a lean "healthy" diet, most probably has health benefits,

Further more one of the papers concentrates on the QUALITY of calories more than on the actual volume.

Most of the papers don't take into consideration the overall fitness and exercise the participants go through.

Most people who watch their diet also are more physically active.

 

And there's this

 

Conversely, high protein intake was associated with reduced cancer and overall mortality in respondents over 65, but a 5-fold increase in diabetes mortality across all ages

Is that supposed to be an argument in favor of CR or against?

Because if we're talking about lifespan I'd think over 65 mortality would be the factor you have to consider the most.

 

 

We show that treatment of cultured cells with CR sera caused increased expression of stress-response genes and enhanced tolerance to oxidants.

 

Well probably has to do with the previous passage I quoted, people undergoing CR probably suffer from more oxidative stress and have an increased cancer risk. That's not a good thing.

 

Looking at all the papers you posted I think some of them actually prove my suspicion that people on a normal or even on a high calorie diet might have a better chance at a longer lifespan if they're fit and physically active throughout most of their lives.

 

[Kalliste]

This issue is real muddy water, you should be careful not to make too firm assertions about this or that.

 

I suspect that once we have high quality methods to profile individual health (by analyzing genetics, epigenetics, gut flora and so on) we will discover that:

1. Some people need low caloric diets and moderate exersize

2. Some people are fine with intensive exercise and high calorie diets

3. Some people... And so on.

 

There have been several studies showing very high incidence of carotid and peripheral atherosclerosis among high performance athletes. We all know about countless runners, soccerplayers and so on who die of sudden cardiac arrest.

 

 

[Darryl]

One way of avoiding the reverse causation found in some mortality vs. BMI studies (from smoking, existing disease, or malnutrition) is to look at long term followups of initially healthy cohorts. Fortunately, table 2 of this paper permits this:

 

Berrington de Gonzalez, A., Hartge, P., Cerhan, J. R., Flint, A. J., Hannan, L., MacInnis, R. J., ... & Thun, M. J. (2010). Body-mass index and mortality among 1.46 million white adults. New England Journal of Medicine, 363(23), 2211-2219.

 

 

For most people, achieving that near 20 BMI minima for long-term, all-cause mortality risk in middle age requires some degree of either caloric restriction or intense endurance exercise. Both accomplish some similar metabolic ends via AMPK upregulation.

 

And those "low-normal" BMIs may not be ideal for the elderly, where too-little IGF/mTOR activation etc leads to frailty and quality of life issues. But I've some way to go till I'm 70 and need to start worrying about sarcopenia.

 

CR proponent Roy Walford suggested ideal CR results came from reducing weight to 15% below the "set point" our weight gravitated towards - my "set point" is somewhere around a 28 BMI (and obesity is common in my family), and that's on a low-fat vegan diet for 4 years. My Walford CR BMI might be around 24. But my ever receding goal weight is still BMI 22. 

Edited by Darryl, 25 August 2014 - 06:54 PM.

[John Schloendorn]

I've been meaning to start posting research that's based on humans and goes AGAINST mice proven life extension research, and I think I'll be doing it a lot from now on.

 

 

Excellent.  Please do.  And enjoy the flak

 

Here are some fun ones:

 

CR lengthens live span in some lab strains, shortens it in others, and has no effect in wild-caught mice (PMIDs 19878144, 17054664).  

 

 strain variation caloric restriction.jpg   43.87KB   4 downloads

 

If mice aren't even like other mice, then what does that do for the hypothesis that some mice are like most humans?  If I'm looking for funding to do a CR experiment, this data allows me to pre-specify both the direction and the magnitude of the life extension I will see with astounding fidelity, just by selecting the right strain.  Is this really an activity we want to reward with more free grant money? 

 

 

And another favorite:  chronic cigarette smoke inhalation extends live and cleanly decelerates aging in the standard lab strain B6 (15944214)

 

 smoking extends mouse life.jpg   39.86KB   2 downloads

 

 

[scottknl]

 

 And there's this

Quote

 

Conversely, high protein intake was associated with reduced cancer and overall mortality in respondents over 65, but a 5-fold increase in diabetes mortality across all ages

Is that supposed to be an argument in favor of CR or against?

Because if we're talking about lifespan I'd think over 65 mortality would be the factor you have to consider the most.

 

regarding my earlier post:

 

 

http://www.ncbi.nlm....pubmed/24606898 -  Respondents aged 50-65 reporting high protein intake had a 75% increase in overall mortality and a 4-fold increase in cancer death risk during the following 18 years. These associations were either abolished or attenuated if the proteins were plant derived. Conversely, high protein intake was associated with reduced cancer and overall mortality in respondents over 65, but a 5-fold increase in diabetes mortality across all ages

 

So I guess based on that study one would want to follow a low protein diet from ages 50-65  and avoid the 75% increase in overall mortality and 4-fold increase in cancer death risk.  Then after age 65 raise protein intake somewhat while following a CRON diet with careful glucose management in order to take advantage of the  reduced cancer and overall mortality in respondents over 65.  Seems like pretty good advice to me. After all you need to go thru ages 50-65 in order to get to the post 65 age group.

 

 

and regarding your other response :

 

Quote

 

We show that treatment of cultured cells with CR sera caused increased expression of stress-response genes and enhanced tolerance to oxidants.

 

Well probably has to do with the previous passage I quoted, people undergoing CR probably suffer from more oxidative stress and have an increased cancer risk. That's not a good thing.

 

Looking at all the papers you posted I think some of them actually prove my suspicion that people on a normal or even on a high calorie diet might have a better chance at a longer lifespan if they're fit and physically active throughout most of their lives.

 

You seem to have gotten the gist of it wrong.  CR doesn`t cause oxidative stress -- it actually decreases oxidative stress because autophagy increases which removes damaged mitochondria when one practices CR.  CR creates better responses to stressors and results in better outcomes. There have been many studies where toxins or blood flow interruption are used to create stresses in lab animals and the results are better in the CR groups.

Edited by scottknl, 25 August 2014 - 07:26 PM.

[niner]

CR lengthens live span in some lab strains, shortens it in others, and has no effect in wild-caught mice (PMIDs 19878144, 17054664).  

 

strain variation caloric restriction.jpg

 

If mice aren't even like other mice, then what does that do for the hypothesis that some mice are like most humans?  If I'm looking for funding to do a CR experiment, this data allows me to pre-specify both the direction and the magnitude of the life extension I will see with astounding fidelity, just by selecting the right strain.  Is this really an activity we want to reward with more free grant money?

 

At first glance this is pretty damning, but then I saw that each and every strain was at 40% CR.  That's a lot of CR, and is probably too much for some strains.  If they had taken the strains that were harmed most by 40% CR, and tried to find a level of CR that extended their lifespan, it would be more interesting.  This paper at least shows us that too much CR is too much...    I don't want to sound like I'm arguing in favor of the common notion that any random strain of mouse is just a little human with fur- I'm not.  I'm just not sure that this particular paper is very good evidence for the "CR is crap" viewpoint on offer in this thread.

[corb]

If mice aren't even like other mice, then what does that do for the hypothesis that some mice are like most humans?  

Exactly. And as Cosmicalstorm pointed out couple of posts up, humans are probably not the same as well, expecting an unified result from something like dieting is crazy .

 

 

You seem to have gotten the gist of it wrong.  CR doesn`t cause oxidative stress -- it actually decreases oxidative stress because autophagy increases

Autophagy is also hijacked by some cancers to help them grow. Nothing in your body is that perfect, otherwise you wouldn't get sick. And it's also the reason why even though it lowers the risk of cancer it doesn't eliminate it.

Buuuut, I'll coincide on this, generally autophagy is good.

 

edit: oh and forgot to add - you probably won't get the same increase in autophagy in humans after all our metabolism is quite different from mice metabolism. Already posted a paper about that in my second post.

 

 

"CR is crap" viewpoint on offer in this thread.

Never said it's crap again go back to post one, I'm pretty sure it has some benefits for some people living certain life styles, just not anything that will give you ten extra years of life universally. Unless you're morbidly obese and young enough for it to matter.

 

My viewpoint has been clear from post one - negligible lifespan benefits.

Edited by corb, 25 August 2014 - 09:19 PM.

[Gerrans]

 

Hmm...very interesting.  You completely ignore the studies on CR volunteers and their excellent lipids and other numbers when you make these conclusions.  The seventh day adventist trials show us that basic lifestyle changes can make a difference of 8 - 9 years in lifespan.  One should expect the CR to do somewhat better than that since their lifestyle changes are similar, but with all the nutrition and fewer calories.

 

 

 

It is not that I ignore the studies supporting calorie restriction. I have diligently read many of them, because, believe you me, if I thought calorie restriction could extend my lifespan I would do it. I am capable of it, which is why I looked into it. But my impression of the evidence is that it is by no means straightforward; and for that reason I believe my deliberately becoming underweight would be a gamble. For instance, you quote the Adventist studies, but they show also that eating nuts correlates with lower mortality. Yet nuts are very high calorie foods. If I gave up nuts to get my weight down, might I not be giving up one life-extending practice in favour of another?

 

I tend to agree with those who think the reason the calorie restriction people are faring well is the nutrition rather than the calorie restriction as such. I would like to see a study comparing healthy, fit people in the lower normal BMI category to calorie-restricting people, with both groups eating healthy diets. I find it hard to believe there would be much difference.

 

As for mouse studies, a useful experiment would compare two groups of normal, healthy mice, one being calorie restricted, the other being fed an amount to keep them non obese, and both being fed on the healthiest foods for mice. The study should start once the animals are mature, because restricting the calories of juvenile rats has no relevance to humans (we cannot ethically restrict the calories of children, as a rule). Since calorie restriction is voluntary, it should be considered for humans only from the age of consent onwards. In my opinion, frankly, it is unwise to start lifelong calorie restriction until the age of 21, since some people are still growing till then.

 

*

 

Personally, I would feel vulnerable if I was too light. I fear I would fare worse in a fight, a car crash, an accident, a serious illness. Also--and this is a subjective view--I feel calorie restricters look terrible. The men, in particular (because men have larger heads than women, usually), look to me like the Mekon (Eagle comic reference there!), with their bony hollow-eyed deathsheads perched on those stalk-like necks. They beam spookily out of their YouTube videos as if they think they are the picture of health, but I suspect one of the delusions of calorie restriction is that you believe you look better than you do. Which may be because, dare I say it, the obsession with undereating for life extension overlaps in some respects with anorexia.
 

Edited by Gerrans, 26 August 2014 - 08:57 AM.

[Brett Black]

I try to mix in some more individual-tailored factors regarding weight and diet...

Taking into consideration individual body shape/morphology and composition may be more important than just weight or BMI. Waist-to-height ratio has shown to be a potentially more accurate measure of health and mortality risk than BMI. Central(around the belly, especially visceral fat) adiposity seems like it may be the big risk factor rather than just being heavy. From this, the message is to keep the waist slim.

A family and/or personal history of propensity to easily gain weight or overweight/obesity may suggest it is a good idea to stay on the lower end of the ideal weight range, to provide a buffer zone for weight maintenance. Conversely a family and/or personal history of difficulty in gaining weight or being naturally skinny may suggest attempting to stay at the upper end of the ideal weight range as a protective buffer against unexpected sources of weightloss like illness.

A family or personal history of osteoarthritis may suggest maintaining a weight on the lower end of ideal also, to reduce risk.

Several studies have shown than lean(or fat-free?) body mass is inversely associated with mortality, whilst body fat mass is positively associated with mortality. The message here is to maximize muscle mass(and bone mass?) whilst minimizing fat mass.

As far as dietary protein goes, it seems there is some evidence that it is animal-derived protein that can increase mortality risk, whilst plant-derived protein may be benign. Also, protein intake may be positively related to cancer, but negatively related to cardiovascular disease, stroke and sarcopenia. So again, individualized protein intake based on individuals' risk factors like personal and family history may shape the choice of protein intake.

[corb]

Those are some good points, if we go back to the original paper I posted, even though cyclists consume large amounts of calories they are fit and with very low body fat and most of them remain physically active and fit in their senior years - which is probably the reason why even though they are on a high calorie diet for most of their adult life they lived more than the average person. I think fitness and bmi is much more important for longevity than diet, because as it was shown in the papers with the rhesus monkeys in the end the bmi had a much larger impact than the diet in general and there was no increase in lifespan when you compared the CR monkeys to the normal bmi monkeys, only when you compared them to obese monkey there was an increase in life expectancy.

Edited by corb, 27 August 2014 - 12:39 PM.

[Kalliste]

You know those cyclists probably consume very high quality food-stuffs as a part of their high caloric diets.

Kenyan long-distance runners eat tons of Ugali for instance.

It's hard to draw conclusions about high calorie diets being good in general from this.

[corb]

You know those cyclists probably consume very high quality food-stuffs as a part of their high caloric diets.

Kenyan long-distance runners eat tons of Ugali for instance.

It's hard to draw conclusions about high calorie diets being good in general from this.

 

As far as I known they fuel up on carbs.
All types of carbs in great quantities, depending on what they are doing - breakfast, before exercise, during exercise,  after exercise, dinner  - they choose a carb with a different glycemic index. Foods rich in carbs are pretty cheap and widely available everywhere. Wheat, rice, rye, barley, potatoes fruits like banans and melons, etc. They also eat white meat during their "resting" phase. Cheap stuff.

 

Unlike CR diets they mostly concentrate on high and mid GI carbs.

And while I was reading about it (not because I don't know I actually bike myself, just needed to get the terminology down, english is not my native language after all) I read something even more intriguing, some cyclists, probably sprinters because they are bulkier, have eaten up to 9000 (nine thousand, thats a week and a half worth of CR right there) in some stages of the races.

It's anti-CR however you look at it. Yet they clearly do not age faster, or die younger than the typical person.

Edited by corb, 27 August 2014 - 11:09 PM.

[Brett Black]

Those are some good points, if we go back to the original paper I posted, even though cyclists consume large amounts of calories they are fit and with very low body fat and most of them remain physically active and fit in their senior years - which is probably the reason why even though they are on a high calorie diet for most of their adult life they lived more than the average person. I think fitness and bmi is much more important for longevity than diet, because as it was shown in the papers with the rhesus monkeys in the end the bmi had a much larger impact than the diet in general and there was no increase in lifespan when you compared the CR monkeys to the normal bmi monkeys, only when you compared them to obese monkey there was an increase in life expectancy.

I don't have the reference right now, but I think there was a rodent lifespan experiment that compared sedentary rodents eating as much as the wanted, with exercising rodents eating as much as they wanted , with calorie restricted rodents(maybe one group exercising and one sedentary.) I could be wrong, but as far as I can recall the sedentary calorie restricted group did the best and the sedentary ad-libitum("all-they-can-eat") did the worst, with the exercising group somewhere in between.

And while I was reading about it (not because I don't know I actually bike myself, just needed to get the terminology down, english is not my native language after all) I read something even more intriguing, some cyclists, probably sprinters because they are bulkier, have eaten up to 9000 (nine thousand, thats a week and a half worth of CR right there) in some stages of the races.
It's anti-CR however you look at it. Yet they clearly do not age faster, or die younger than the typical person.

The relationship between calories and lifespan may not be linear. For instance, low calorie diets might lengthen lifespan compared to average calorie diets, but that does not necessarily mean that high calorie diets will shorten lifespan compared to average calorie diets. If that's the case, and the relationship between calories and lifespan is not linear, then using data from hypercaloric diets to try to debunk calorie restriction is a flawed argument.

[Gerrans]

And while I was reading about it (not because I don't know I actually bike myself, just needed to get the terminology down, english is not my native language after all) I read something even more intriguing, some cyclists, probably sprinters because they are bulkier, have eaten up to 9000 (nine thousand, thats a week and a half worth of CR right there) in some stages of the races.

It's anti-CR however you look at it. Yet they clearly do not age faster, or die younger than the typical person.

 

 

It seems from this thread that few people advocate strict calorie restriction; so you might pause in your crusade to check whether you are not attacking a straw man. I think in the real world most people use their common sense with regard to calories and bodyweight.

 

Your point that I quote seems again to suggest that you define calorie restriction as eating below calorie requirement. But in fact we all have to meet our calorie requirement or we will soon die. So, once a calorie restricter settles at their chosen weight, after that they will match their calorie consumption to calorie output, much like anyone else who stays at a level weight, including a cyclist who eats 9000 calories a day.

 

[corb]

OBJECTIVE:

To evaluate the effects of body composition as a function of lean mass index (LMI) and body fat (BF) on the correlation between increasing body mass index (BMI; calculated as the weight in kilograms divided by the height in meters squared) and decreasing mortality, which is known as the obesity paradox.

PATIENTS AND METHODS:

We retrospectively assessed 47,866 patients with preserved left ventricular ejection fraction (≥50%). We calculated BF by using the Jackson-Pollock equation and LMI using (1 - BF) × BMI. The population was divided according to the sex-adjusted BMI classification, sex-adjusted LMI classification, and sex-adjusted BF tertiles. The population was analyzed by using multivariate analysis for total mortality over a mean follow-up duration of 3.1 years by using the National Death Index, adjusting for left ventricular ejection fraction, left ventricular mass index, age, sex, and relative wall thickness.

RESULTS:

In the entire population, higher BMI was narrowly associated (hazard ratio  , 0.99; P<.001) with lower mortality. The higher LMI group was clearly protective (HR, 0.71; P<.001), whereas BF tertile was associated with lower mortality only if no adjustment was made for LMI (HR, 0.87; P<.001 without LMI; HR, 0.97; P=.23 with LMI). In the lean patients, low BMI was clearly associated with higher mortality (HR, 0.92; P<.001) and lower BF tertile was associated with lower mortality only if no adjustment was made for LMI (HR, 0.80; P<.001 without LMI; HR, 1.01; P=.83 with LMI). The underweight patients stratified by BF seemed to have an increased mortality (HR, 1.91; 95% CI, 1.56-2.34) that was independent of LMI. However, in obese patients, both BMI (HR, 1.03; P<.001) and BF (HR, 1.18; P=.003) were associated with higher mortality, even after adjusting for LMI, which remained protective (HR, 0.57; P<.001) independently of BF.

CONCLUSION:

Body composition could explain the inverse J shape of the mortality curve noted with increasing BMI. Body fat seems to be protective in this cohort only if no adjustment was made for LMI, although being underweight stratified by BF seems to be an independent risk factor. Lean mass index seems to remain protective in obese patients even when BMI is not.

Copyright © 2014 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

 

http://www.ncbi.nlm....pubmed/25039037

 

Being underweight is a risk factor.

Being overweight but fit is not.

Can't wait for the mouse studies which are supposed to overrule this human study.

 

 

It seems from this thread that few people advocate strict calorie restriction;

 

That is one problem, there is no clear definition of CR, it goes from starving to what most southern europens like me consider a normal diet. Doesn't have much to do with my understanding on the subject, more with the way the people who swear by it handle it.

Edited by corb, 28 August 2014 - 11:25 AM.

[to age or not to age]

With regard to CR and monkeys;  I was recently among scientists who said that in fact, CR does extend the lifespan of

monkeys.  It turns out that the experiment that claims CR doesn't work in monkeys was flawed.  I will try to find out more

details on this.

[Gerrans]

With regard to CR and monkeys;  I was recently among scientists who said that in fact, CR does extend the lifespan of

monkeys.  It turns out that the experiment that claims CR doesn't work in monkeys was flawed.  I will try to find out more

details on this.

 

The two main studies that I know of used different methods. The University of Wisconsin one that showed calorie-restricted monkeys to live longer than controls allowed the control monkeys to eat ad libitum from a relatively unhealthy diet, containing a higher percentage of sugar than the diet of the calorie-restricted monkeys. In my opinion, the fact that the control monkeys were eating ad libitum muddies the waters.

 

The National Institute of Aging study fed both calorie-restricted animals and control animals a healthy diet and, instead of being allowed to eat ad libitum, the control animals were fed the right amount to keep them at a healthy weight. This study has been accused of confounding the matter by restricting the diet of the control animals, though to my way of thinking this made those animals comparable to humans who eat a healthy diet and stay at a normal weight. But the fact that the low-calorie animals did not live any longer than the normal-calorie animals when they were both given a healthy diet seems to me instructive and--for my money--unsurprising.
 

[to age or not to age]

I don't know, I think people should read this and make their own judgement about CR and  monkeys http://www.scienceda...40401111957.htm

 

[corb]

 

The Wisconsin scientists began to see diabetes among the control animals while they were still in the prime of life, within six months after beginning their study.

 

Now I'm not sure what they fed the monkeys, but, getting diabetes 6 months into the trial is a bit suspicious.

Edited by corb, 28 August 2014 - 08:07 PM.

[scottknl]

The monkey CR thing has been commented excessively in the thread I link to below.  I include here a link to my summary post near the end of discussion:

http://www.longecity...e-7#entry550928

 

I don't think much more speculation is really needed if you read all the postings in that thread.  Really, Corb, a lot of what you say has already been expressed and defended and some of it is not correct.

[John Schloendorn]

Now I'm not sure what they fed the monkeys, but, getting diabetes 6 months into the trial is a bit suspicious.

 

 

Thank you Corb.  It always makes me very happy to see someone willing to go beyond parroting fake headlines, and actually ask questions about the data, right where it hurts.