87 replies to this topic

[DR01D]

I have a special scale that measures muscle mass, body fat, etc. etc.

According to my scale my basal metabolic rate is 1566 calories per day. That's how many calories I'll burn if I don't get out of bed and I know from experience that it's pretty close to correct +/- a few calories.

If I ate 1200 calories per day it wouldn't take too many months before I was either dead or in the hospital.

Edited by DR01D, 25 February 2013 - 02:30 AM.

[Hebbeh]

CR is not 20% less than maintenance. Anyone who consumes less than maintenance will lose weight and eventually die of starvation.

CR = maintenance.

That's not been my experience. 95% of the regimine is calories in - calories out.

Absolutely not true. The CR regimen calls for 20% less than maintenance....if you're eating maintenance, you certainly aren't CR now, are you? And you won't die of starvation! You will lose your muscle mass and as you lose your lean mass, your "new" maintenance and "new" lower metabolism will decrease. Your body will "adjust" and it is this genetic adjustment that brings the supposed benefits of CR. Not eating below maintenance will bring no metabolic adjustments and no benefits....that is the basic premise of CR. Eating at maintenance to preserve your muscle mass is just simply healthy living....like everybody else (that isn't a couch potato)....but it isn't CR.

I have a special scale that measures muscle mass, body fat, etc. etc.

According to my scale my basal metabolic rate is 1566 calories per day. That's how many calories I'll burn if I don't get out of bed and I know from experience that it's pretty close to correct +/- a few calories.

If I ate 1200 calories per day it wouldn't take too many months before I was either dead or in the hospital.

Like I said, you wouldn't die...but your body would sacrifice your muscle mass to adapt to a new lower metabolism and lower metabolic rate and this adaption is what brings about any benefit of CR. You can't both have muscles and be CR....that is a contradiction.

It wouldn't be called caloric restriction if you allowed yourself to eat maintenance. Maintenance is simply healthy living like everybody else but it's not CR. And you won't starve to death...that's too simplistic and indicates you don't understand the science behind it.

Edited by Hebbeh, 25 February 2013 - 03:05 AM.

[DR01D]

your body would sacrifice your muscle mass to adapt to a new lower metabolism and lower metabolic rate and this adaption is what brings about any benefit of CR. You can't both have muscles and be CR....that is a contradiction.

I disagree. Scientists don't know why CR works.

I'm not convinced that maintenance without muscle mass is healthier than maintenance with muscle mass. My blood pressure dropped from 135/80 to 106/72 when I cut my calories. Something significant changed when I reduced the number of calories in my diet that was independent of muscle mass.

Joe Cordell from the Oprah video eats 1950 calories per day and if you watched him in the BBC documentary, Eat, Fast and Live Longer he demolished Dr. Michael Mosley on all of the health tests. Joe was rated decades healthier than his biological age would suggest and he's not scraping by on 1200 calories per day.

[xEva]

That's interesting. We (DR01D, Hebbeh & I) have different views on what CR is and how it works. I agree with Hebbeh that the key is metabolic adjustment, but I disagree with him that CR must come with a loss of muscle mass (unless it is an excessive muscle mass, like in some grotesque body builders) or diminished physical activity. IMO the metabolic adjustment comes with greatly improved metabolic efficiency, which simply means that one needs less calories to maintain the same body and lifestyle.

What you DR01D are saying with your high tech scale is based on an average person metabolism, which is not an efficient metabolism. How far a calorie can go is not set in stone. It depends on how well mitochondria operate, what genes are on and what are off, the hormonal background, etc. In order to get one's metabolism into a more efficient mode, one needs to fast for at least 5 days, after which, an adjustment to a lower calorie diet will be possible, due to the epigenetic changes that will take place during the fast. That's what I meant by reeling in the metabolism.


@Hebbeh, I also thought that maintenance implies a basic metabolic rate, and if so, no-one can go below it without beginning to starve. In my understanding, CR is honing in on the metabolism, making our physiology efficient to the maximum. If I may use an analogy, I'd bring up a modern engine that requires much less fuel for a much higher mileage than, say, a Ford circa 1905. In this I diverge from both of you guys, cause for me then CR is not about calories but about the efficiency of the 'engine'.

Edited by xEva, 25 February 2013 - 04:40 AM.

[Hebbeh]

your body would sacrifice your muscle mass to adapt to a new lower metabolism and lower metabolic rate and this adaption is what brings about any benefit of CR. You can't both have muscles and be CR....that is a contradiction.

I disagree. Scientists don't know why CR works.

I'm not convinced that maintenance without muscle mass is healthier than maintenance with muscle mass. My blood pressure dropped from 135/80 to 106/72 when I cut my calories. Something significant changed when I reduced the number of calories in my diet that was independent of muscle mass.

Joe Cordell from the Oprah video eats 1950 calories per day and if you watched him in the BBC documentary, Eat, Fast and Live Longer he demolished Dr. Michael Mosley on all of the health tests. Joe was rated decades healthier than his biological age would suggest and he's not scraping by on 1200 calories per day.

Granted and I agree but that is not based on the definition of CR and what has shown to extend life in lower animal experiments. Your definition of CR is not the scientific definition that has been proven in animal experiments. By your definition, I would be CR also....and at almost 56 I'm sure I can match your health markers (and Cordell's)....and although I no longer actively body build, I stay in shape also with decent lean mass and maintain less than 10%BF....but I don't fool myself to think I am caloric restricted in the manner has been conducted in the experiments to show life extension. Mice had to be 50-60% caloric restricted to show appreciable life extension...at the expense of smaller body size.

And I wasn't impressed with Cordell...they claim he has the health markers of a 20 year old but he was really huffing and puffing while dogging it on the treadmill AT A WALK. And he carry's absolutely no muscle mass.

[DR01D]

What you DR01D are saying with your high tech scale is based on an average person metabolism, which is not an efficient metabolism.

I don't know how accurate my scale is but when my calories go below 1800 calories I lose weight. That tells me that although My scale might not be perfect it's reasonably accurate more or less. It's the same one that Dr. Micheal Mosley used in the BBC show on calorie restriction.

Edited by DR01D, 25 February 2013 - 05:04 AM.

[Hebbeh]

@Hebbeh, I also thought that maintenance implies a basic metabolic rate, and if so, no-one can go below it without beginning to starve. In my understanding, CR is honing in on the metabolism, making our physiology efficient to the maximum. If I may use an analogy, I'd bring up a modern engine that requires much less fuel for a much higher mileage than, say, a Ford circa 1905. In this I diverge from both of you guys, cause for me then CR is not about calories but about the efficiency of the 'engine'.

That isn't the definition of the experiments in animals that resulted in life extension and the basis of the CR movement based on those longevity experiments. For instance in mice:

[DR01D]

@Hebbeh, I also thought that maintenance implies a basic metabolic rate, and if so, no-one can go below it without beginning to starve. In my understanding, CR is honing in on the metabolism, making our physiology efficient to the maximum. If I may use an analogy, I'd bring up a modern engine that requires much less fuel for a much higher mileage than, say, a Ford circa 1905. In this I diverge from both of you guys, cause for me then CR is not about calories but about the efficiency of the 'engine'.

That isn't the definition of the experiments in animals that resulted in life extension and the basis of the CR movement based on those longevity experiments. For instance in mice:

I've never had a good feel for what "fully fed" really means.

My scale rates my Basal Metabolic Rate at 1566. If I have a low activity day I need around 1800 calories per day for maintenance. Those numbers are in general agreement with each other.

But if 1800 is "fully fed" 50% CR puts me at 900 calories. 60% puts me at 720 calories. Either one of those numbers would land me in the hospital.

So it's gotta be higher than my base.

If fully fed =
3000 calories - 1800 = 40% CR
2500 calories - 1800 = 28% CR
2000 calories - 1800 = 10% CR

[Hebbeh]

I've never had a good feel for what "fully fed" really means.

My scale rates my Basal Metabolic Rate at 1566. If I have a low activity day I need around 1800 calories per day for maintenance. Those numbers are in general agreement with each other.

But if 1800 is "fully fed" 50% CR puts me at 900 calories. 60% puts me at 720 calories. Either one of those numbers would land me in the hospital.

So it's gotta be higher than my base.

If fully fed =
3000 calories - 1800 = 40% CR
2500 calories - 1800 = 28% CR
2000 calories - 1800 = 10% CR

With animals, typically "fully fed" means around maintenance as animals will self regulate their food intake....animals typically don't binge or pig out like humans tend to. Animals will tend to eat to maintain a healthy weight...unlike many humans...they will stop eating when full or satisfied.

[DR01D]

With animals, typically "fully fed" means around maintenance as animals will self regulate their food intake....animals typically don't binge or pig out like humans tend to.

Animals gorge themselves just like modern humans if extra food becomes available. For example dogs and cats get obese, horses will eat themselves sick etc etc.

Wild animals are thin for the same reason that humans used to be thin. There is never enough food to go around. If the food supply increases more young survive to adulthood. The larger population eats the surplus and everyone is back to square one.

Thomas Robert Malthus described this predicament a couple of hundred years ago and it's probably the reason CR works. Food scarcity is something that every animal faced on a daily basis so they evolved systems that utilized it for their benefit.

Autophagy is another hunger driven system that evolution provided animals to keep them healthy.

Edited by DR01D, 25 February 2013 - 02:03 PM.

[nowayout]

Seems like there is a lot of confusion between eating at maintenance calorie level and CR which is 20% less than maintenance.

Eating less than maintenance would mean you would be continuously losing weight. At some point on CR the idea is that your weight would stabilize and you would then maintain it, isn't it, otherwise you wouldn't live very long, would you?

[DR01D]

Seems like there is a lot of confusion between eating at maintenance calorie level and CR which is 20% less than maintenance.

Eating less than maintenance would mean you would be continuously losing weight. At some point on CR the idea is that your weight would stabilize and you would then maintain it, isn't it, otherwise you wouldn't live very long, would you?

I think you hit the exact point that most people miss. CR = maintenance. It's not less than maintenance.

That being the case which person is healthier?

Person 1
Diet: 1500 calories
Lifestyle: Sedentary
Muscle Mass: 25% of body
Fat Mass: 12% of body

Person 2
Diet: 1800 calories
Lifestyle: Active
Muscle Mass: 45% of body
Fat mass: 12% of body

I'm open to the idea that Person 1 might be healthier but I'm not convinced. Person 2 might be healthier or both could be equally healthy. The science is not definitive and might not be for decades to come.

I kept my muscle mass and my blood pressure dropped just like it did in the CR studies. So my hunch is that Person 2 is doing just fine.

In any case compared to the average American both are on some pretty significant CR.

Edited by DR01D, 25 February 2013 - 02:16 PM.

[DR01D]

By your definition, I would be CR also....and at almost 56 I'm sure I can match your health markers (and Cordell's)....and although I no longer actively body build, I stay in shape also with decent lean mass and maintain less than 10%BF....

If you've got 10% body fat at age 56 you are a beast. According to my scale the lowest I've ever hit is like 11%. A lot of the time I come in around 12.5% I think.

My muscle mass is 42%. So although I'm in great shape I'm no Arnold Schwarzenegger.

I'm only 5'7" and weigh 145 pounds. My goal is to hit 150 pounds over the next year or two. I can't grow any faster eating so little. Plus I'm 43 which might slow me down some.

Edited by DR01D, 25 February 2013 - 02:24 PM.

[Hebbeh]

11% isn't that impressive...especially for CR. Bodybuilders get sub 5% for contest and many athletic competitions with weight classes will see athletes at sub 7-8%. competitive cyclists don't carry any fat and I'm sure are well below 10%. I've competed in all those sports in my lifetime and was always shredded. Fitness competitors and models are shredded at less than 7% to get defined abs. I used to maintain at 7-8% as measured both by calipers and bioelectrical impedance within the last couple years but currently don't have the time required to dedicate to that level of fitness and have to be satisfied with approx 10% but will be in shape by summer for another season climbing 14teeners. Anyway, 11-12% BF is in no way CR.

And if you've looked at pics of dissected fully fed lab mice...they don't carry much fat and certainly aren't obese.

[DR01D]

11% isn't that impressive...especially for CR. Bodybuilders get sub 5% for contest and many athletic competitions with weight classes will see athletes at sub 7-8%. competitive cyclists don't carry any fat and I'm sure are well below 10%. I've competed in all those sports in my lifetime and was always shredded. Fitness competitors and models are shredded at less than 7% to get defined abs. I used to maintain at 7-8% as measured both by calipers and bioelectrical impedance within the last couple years but currently don't have the time required to dedicate to that level of fitness and have to be satisfied with approx 10% but will be in shape by summer for another season climbing 14teeners. Anyway, 11-12% BF is in no way CR.

This isn't a competition. If you've got a study that shows that the benefits of CR won't kick in at 11% to 12% bodyfat I'd love to see it.

Long-term calorie restriction is highly effective in reducing the risk for atherosclerosis in humans

We studied 18 individuals who had been on CR for an average of 6 years and 18 age-matched healthy individuals on typical American diets.

The CR group were leaner than the comparison group (body mass index, 19.6 ± 1.9 vs. 25.9 ± 3.2 kg/m²; percent body fat, 8.7 ± 7% vs. 24 ± 8%).

I believe those people are from the CR society and their average bodyfat was 8.7%. That's only a few percent lower than me. Plus I'm not measuring myself with calipers, I'm using a scale. 11% or 12% is a decent estimate but it's still an estimate.

[DR01D]

The calorie restriction group in this study ate roughly the same thing I eat, had roughly the same body fat I have and measured the lowest core body temperature of the 3 groups. There isn't a specific, low bodyfat percentage that triggers the benefits of CR. it's simply not true.

Long-term calorie restriction, but not endurance exercise, lowers core body temperature in humans

Long-term CR with adequate nutrition in lean and weight-stable healthy humans is associated with a sustained reduction in core body temperature, similar to that found in CR rodents and monkeys.

The CR and EX groups were significantly leaner than the WD group. Energy intake was lower in the CR group (1769±348 kcal/d) than in the WD (2302±668 kcal/d) and EX (2798±760 kcal/d) groups

CR Group
Total body fat (%): 13.0±5.3

Exercise Group
Total body fat (%): 15.2±5.1

Western Diet Group
Total body fat (%): 21.8±6.8

Edited by DR01D, 25 February 2013 - 06:14 PM.

[Hebbeh]

Personally I don't believe CR will extend lifespan in humans beyond normal healthy diet and exercise...and I agreed with you in an earlier post in which you indicated the same. But like I said, you're not practicing true CR if you're eating at maintenance at 11-12%. And if you think there isn't much difference between 7-8% and 11-12% then get down to 7% and report back. And I'm certainly not in any competition with you...but the record needs to be corrected as to what true CR really is....and 10-12%BF was just an average male a generation ago....look that up. And 10% BF males haven't provided excessive longevity in the last 100 years.

[DR01D]

But like I said, you're not practicing true CR if you're eating at maintenance at 11-12%.

That's your opinion of what true CR is but in the study I posted the CR group had an average body fat of around 13%. There is another study (which I can't find right now) where the CR group averaged 11.5% body fat.

CR isn't directly about body fat. To be fair scientists aren't entirely sure what it's about.

But this I know for certain. When I cut my calories my blood pressure dropped hard.

Also for nearly 20 years I had ganglion cysts in both wrists but a few months after I cut my diet they disappeared and never came back. I had grown so used to them that I thought they would be with me for life. When I first noticed they had disappeared I couldn't believe it. I kept trying to find them.

Maybe if I lost another 2 or 3 pounds of fat I would get even more benefits. But it's doing something right now.

[DR01D]

addendum:

My sense is that calorie restriction is dose dependent. That's what the mice charts always show. There isn't a particular number where it turns on and off.

Some is good. More is better..... until your pancreas turns off and your insulin goes haywire.

Edited by DR01D, 25 February 2013 - 08:08 PM.

[nowayout]

My sense is that the evidence for CR is too weak to justify doing it if it interferes with your preferred lifestyle (including attracting people for dating, socializing, eating with friends, having a body you find esthetically pleasing) or if it exacerbates any obsessive-compulsive, body-dysmorphic, or control issues you may have.

If you find you don't have to give up aspects of living fully and sanely now while doing CR, then go for it. Otherwise you are probably going to have regrets about missing out in a decade or four when your youth is gone anyway.

Edited by viveutvivas, 25 February 2013 - 08:38 PM.

[scottknl]

My interpretation of what is or is not CR doesn't involve BMI, % body fat or a certain number of calories. There is a constellation of biomarkers that show up when someone is calorie restricted. These include lower blood pressure (S & D), lower pulse rate, lower LDL, generally lower blood sugar, lower body temperature and lower inflammatory markers, and lower IGF-1. When you have all of these things happening at the same time when you're restricting your dietary intake, then you're in CR. Different people respond differently to a reduction of calories depending on their starting point, but the key set of biomarkers always shows up for people on CR. Some people on CR can retain an amazing amount of fat given their calorie intake, so BMI and body fat % are kind of useless to use as benchmarks. BMR might be useful, but who has time and opportunity to measure it?

I met Joe Cordell in 2011 and had lunch with him a few times. He's not super skinny and moves just like any reasonably healthy person. We walked several blocks to go eat and I didn't find that he was particularly slow or unhealthy in any way. I expected him to look really young for his age, given how long he has been doing CR, but in reality he just looked healthy and good for his age. We swapped stories about CR stuff and I found him to be friendly and intelligent.

Edited by scottknl, 25 February 2013 - 11:50 PM.

[anagram]

I feel that part of the reason why CR has a positive effect on life span is because it majorly reduces stress. I did CR for 6 years and I did not feel stress at all, it was like I was living in a fantasy world. CR was a double sided blade, I would not feel stress to do work(it needs some stress), I was so lazy that people would think I was trying to be that lazy, I did not have any initiative. It was good because I was able to wank my days away care free, I was literally able to wank 7 times in a row. I am off CR, and back to the much less endearing reality. The long lasting positives are better focus, less stress, enjoying life more. CR probably extends human life span some, however I will not spend another 6 years of my life living in a unpronounced dimension of existence marked by its unnatural ecstasy.

-The CR I as doing was legit to, none of that 60% less bull shit. I would go a day eating some yogurt, a banana, and a bagel with lots of butter. Although I was on the cusp of what I though was death, I remained in good health and actually found that i didn't feel hungry anymore. Think of it as succumbing to the void.

[samuilov]

Has anyone seen "Eat, Fast and Live longer" they suggest alternatives to CR such as IF (One day Fasting and One day Feeding) they claim it works just as well. On the fast day they can eat 600 cal and on feed day they can eat anything if you calculate the total weekly calories for this diet and divide by 7 to get the average daily calories it come in about 1500 cal a day.


What do you think?

[DR01D]

Has anyone seen "Eat, Fast and Live longer" they suggest alternatives to CR such as IF (One day Fasting and One day Feeding) they claim it works just as well. On the fast day they can eat 600 cal and on feed day they can eat anything if you calculate the total weekly calories for this diet and divide by 7 to get the average daily calories it come in about 1500 cal a day.


What do you think?

Eat, Fast and Live Longer is the best show on CR ever produced. It used to be on YouTube but the BBC made them take it down.

I do a semi-modified 5/2. On Tuesdays and Thursdays I eat a normal amount of calories but I make sure they include very low protein and I stop eating at noon. That provides me a 17/18 hour fast twice per week. Low protein and fasting causes IGF-1 to plummet.

BTW on the day you eat 600 calories make sure you eat it in one sitting. Your stomach needs to be empty to trigger autophagy. If it was me I'd make that breakfast because when I wake up I'm usually very hungry.

Unfortunately I found that I had a hard time eating 600 calories in a day so a regular 5/2 didn't work for me. That might be because I eat so little on the "5" days.

In another 10 years when my kids move out of the house my wife and I will probably cut back to two meals per day, every day. One meal per day is tough for us but two meals per day is really easy and it gives the body a 17/18 hour fast.

Edited by DR01D, 27 February 2013 - 02:13 PM.

[xEva]

Low protein and fasting causes IGF-1 to plummet.

Do you have any human data to support this?

BTW on the day you eat 600 calories make sure you eat it in one sitting. Your stomach needs to be empty to trigger autophagy.

Your blood sugar has to be low too and so is insulin. Simply having an empty stomach won't do.

One meal per day is tough for us but two meals per day is really easy and it gives the body a 17/18 hour fast.

That's not a fast but a twice-a-day eating lol.

The error you're making is applying rodent data to yourself. Humans have vastly different metabolic rate. What's a CR for a mouse is a real, week long, water-only fast for a man.

[samuilov]

i found this study it seems that low protein consumption does have an effect on igf 1 but not as significant as in mice CLICK

[DR01D]

Do you have any human data to support this?

Long-term effects of calorie or protein restriction on serum IGF-1 and IGFBP-3 concentration in humans

...our data provide evidence that protein intake is a key determinant of circulating IGF-1 levels in humans, and suggest that reduced protein intake may become an important component of anticancer and anti-aging dietary interventions.

But for the average person the best source of info on CR, Fasting, IGF-1, etc. etc. is this...

Eat, Fast and Live Longer
If you can't access the show find the torrent file and download it for free. Google the scientists in the show and read what they've published if you want more in depth info. It's all gold. The study I posted above is by Luigi Fontana who was on the BBC program.

More gold right here...
YouTube: Einstein College Of Medicine: Autophagy, Dr. Ana Maria Cuervo
Long story short, don't snack between meals. An 18 hour fast is a good thing.

Edited by DR01D, 27 February 2013 - 11:15 PM.

[xEva]

Long-term effects of calorie or protein restriction on serum IGF-1 and IGFBP-3 concentration in humans

...our data provide evidence that protein intake is a key determinant of circulating IGF-1 levels in humans, and suggest that reduced protein intake may become an important component of anticancer and anti-aging dietary interventions.

This is the same study that samuilov linked. I remember MR talked about it at length when it came out.

It says that, in contrast to cronies, lowered IGF-1 was found in ad lib vegans, i.e. in those who have very low protein intake throughout, which is very different from what you advocate for reaching the same result (i.e. lowering protein intake somewhat on 2 days a week). It also says that 6 cronies with high protein intake, who agreed to lower it, had their IGF-1 lowered after 6 days.

In other words, your interpretation that simply lowering your protein intake on 2 days a week should lead to lower IGF-1, is unfounded. As for your previous statement that CR lowers IGF-1, this is not true for humans and, if I remember correctly, it was not true for monkeys, but only applies to rodents. This paper also references a 1994 study, according to which IGF-1 was lowered by 40% in humans after a 10-day fast. I could not get that reference's full text, but I am pretty sure that by 'fast' they meant complete absence of nutrients (rather than 'eating twice a day as opposed to 3' as per your interpretation).

Accordingly, it is safe to assume that 10 days of fasting on water only significantly lowers IGF-1 in humans. IMO this explains why CR mice get their IGF-1 lowered too: it is because CR mice actually fast in between feedings. This little detail has been underappreciated by most people on this forum and many researchers alike. IMO, mice show life extension and greater epigenetic changes in response to CR, because they actually fast between meals. It would be very interesting to see whether their lifespan would be extended if rodents were fed every 3 hours while still being calorie restricted. A more frequent feedings would prevent them from going into ketosis of starvation, as they do in between less frequent schedule, and closer match CR in humans.

Just a reminder: mouse breathing rate is ~160 per min, heart rate 480-600 beats per min and, despite having longer telomeres at birth, they loose them 100 times faster than humans, suggesting that their cells divide at 100 times faster rate than ours. Mice also loose 10% of their body weight in 24 h. That would be like a 70 kg man, eating once a day, first gaining and then loosing 7 kg in between meals.

But for the average person the best source of info on CR, Fasting, IGF-1, etc. etc. is this...

Eat, Fast and Live Longer
If you can't access the show find the torrent file and download it for free. Google the scientists in the show and read what they've published if you want more in depth info. It's all gold. The study I posted above is by Luigi Fontana who was on the BBC program.

More gold right here...
YouTube: Einstein College Of Medicine: Autophagy, Dr. Ana Maria Cuervo
Long story short, don't snack between meals. An 18 hour fast is a good thing.

I saw this documentary when it came out. And thank you for posting the link to Dr. Cuervo's interview; it is always a delight to hear her or read her work. In that interview she says that liver cells will do autophagy after several hours of not eating and that a similar process happens in other organs. This little phrase contains a significant detail best seen in this example: to demonstrate autophagy in mouse neurons another group had to fast them for 48h. By then those mice lost 20% of their body weight. This was a serious fast for mice, because towards the end of the 3rd day of fasting, about half of them die of starvation. For comparison, a normal human will loose 20% of his body weight in more than a month of fasting on water only and will die toward the middle of the third month of starvation (obese humans were known to fast on water + some vitamins and minerals for over a year).

This is only to show that your version of CR, while by all means being a much healthier diet than the norm, will never give the results seen in rodents. 90-100 years for a woman and 80-90 for a man is all one can aspire to on this version of CR. IMO the real way to go for real life extension is to really fast regularly in between ad lib periods, like CR'd rodents are forced to do.

Edited by xEva, 28 February 2013 - 06:14 PM.

[DR01D]

In other words, your interpretation that simply lowering your protein intake on 2 days a week should lead to lower IGF-1, is unfounded.

Lower protein 2 days a week does mean lower total protein consumption for the week. Theoretically speaking lower overall protein consumption means lower IGF-1.

it is safe to assume that 10 days of fasting on water only significantly lowers IGF-1 in humans.

In the BBC program Michael Mosely fasted for 3 days and it significantly lowered his IGF-1. I wish the show was still on YouTube so I could check his results but I think he said his IGF-1 dropped by half or a third or something along those lines.

This is only to show that your version of CR, while by all means being a much healthier diet than the norm, will never give the results seen in rodents. 90-100 years for a woman and 80-90 for a man is all one can aspire to on this version of CR. IMO the real way to go for real life extension is to really fast regularly in between ad lib periods, like CR'd rodents are forced to do.

IMHO CR doesn't extend maximum lifespan in humans. Human's probably have the potential to live around 100 years. My hope is that CR increases my healthspan so that I can reach my potential which is probably around 100 years.

I'm not shooting for 120+ although if by some miracle I get there all the better.

Edited by DR01D, 28 February 2013 - 07:46 PM.

[nowayout]

I don't think anybody knows which biomarkers are or aren't necessary for the purported benefits of CR. It's all pretty much speculation.