Talk:Calorie restriction/Archive 1

Archive 1

but this is not the reson

but this is not the reson why i was asking that why does women have more calori thatn men not thing else

What to eat, specifically

People want to know what a human CR diet specifically consists of. Let's write a short section on this near the top. Could you please suggest some sources and references here? --131.193.179.146 (talk) 19:37, 11 July 2009 (UTC)

I don't think the article should say. If a person is going to go on a significantly calorie restricted diet, they need to be paying more attention to the specifics (both macro and micro nutrients) than can be reasonably listed in this article. (The CRON-diet page doesn't even provide specifics; this page certainly doesn't need to.) Additionally, I worry about people going on severe CR diets without cause; as the article currently notes, CR in humans beyond maintaining a healthy weight is not yet shown to have benefits. Astgtciv (talk) 14:31, 18 August 2009 (UTC)

A human CR diet consists of exactly what you'd think from the term "caloric restriction": less calories. Some people feel that the restricted diet still needs to include the same amount of micronutrients - vitamins and such - but even that's not proven. No additional verbiage is needed. Warren Dew (talk) 19:20, 20 October 2009 (UTC)

"CR when not associated with malnutrition ..." --Nutriveg (talk) 19:24, 20 October 2009 (UTC)

Numbered References

I think we need to put in some numbered references next to a lot of claims so that we can associate them with the texts that have shown evidence for such changes. Any thoughts? --Unknown

I agree. Also the part on "Objections to Calorie Restriction" needs a reference to who this michael cooper fellow is. // Lasse

Moved positive info from Objections to Why

Thx for the good article. I found pro-cr info in Objections and moved it to near the end of "Why might CR increase longevity?" I don't know enough about this to rewrite much (except for one copyedit), so flow could use some work. Also, the last paragraph i moved ("Stated levels of Calorie needs may be biased towards sedentary individuals. Calorie Restriction may be more of adapting the diet to the body's needs.") should be explained more -- i wasn't sure what it meant and where to put it. Does this relate to the activity level question in test animals, and if so how? If "Calorie needs [are] biased towards sedentary individuals" vs active ones, wouldn't that mean they're too *low*? Etc. Hope this helps, "alyosha" (talk) 23:26, 3 January 2006 (UTC)

Should be changing inital text

"Except for houseflies (below), animal species tested with CR so far, including primates, rats, spiders and rotifers, have shown lifespan extension"

This statement isn't as correct as it should be. There has been no lifespan extention demonstrated in a published paper with primates. Richard Weindruch's experiments are ongoing and there has been nothing published stating that "lifespan extension" has been "shown". So unless someone puts forth a concluded published trial with primates I'm going to change this. 205.211.168.10 15:02, 7 February 2006 (UTC) Jonathan Graham

Also I added to the Objections section a link to the Housefly article and some text about John Phelan's objection about this being an effect that is really only acheivable on small organisms. Another good reason to change the intro text. Not saying that this wiki is biased but it looks like there has been way more effort put into representing the "pro" side here. 205.211.168.10 15:24, 7 February 2006 (UTC) Jonathan Graham

Searched around for completed primate studies, nothing so far. I did find another ongoing one (other than the one by RW). It shows some evidence at monkeys beating the median age ( I'll read the study in a bit more detail later but that seems like grade 'C' evidence when dealing with such a small sample ) If they were to beat the maximal age that would really drive the point home but considering that these monkeys live 40 years...I wouldn't expect a conclusion any time soon. Also Rhesus monkeys are prone to diabeties which would skew the results somewhat as well.

Also added the study about late-life CR. I'm not sure if we should put an approximate age in there. The rats were introduced at 18 months - what would that be in human years. I've seen places where people have just assumed that you compose them linearly but is it really reasonable to do so.

I've put it under 'objections' which is becoming a less and less applicable title. It sort of depends on exactly what one is 'objecting' to. If this article is about simple calorie restriction as having some (possibly small) benefit on some arbitrary group of creatures then they aren't but in reading this article, it appears to me that what is being advertised here is CR as a generally applicable lifestyle for significant (i.e. greater than maximal) longevity with implication on the idea the humans can do this too. In which case I would call the articles I'm posting "objections". I would think this isn't such a bad thing to be discussing either after all when you read about CR in the media, they aren't talking about how to keep your pet rat alive longer! :-)

205.211.168.10 20:40, 7 February 2006 (UTC)Jonathan Graham

More digging through PM...and we find out that this effect (longevity) may not even be consistant on small organisms. Drosphila may have mixed responses when it comes to CR - at least from the journal abstracts. Also there's a reference to a mouse study that didn't produce longevity. I'll go through these articles when I get a chance. Point being that this wiki, so far makes it sound like there is little reason to believe that this effect isn't universal but now I'm thinking we may want to tone it down a bit.

24.141.146.87 01:14, 8 February 2006 (UTC)Jonathan Graham

CR is one of the few dietary intervention that has been documented to increase both the median and maximum lifespan in a variety of species, among them yeast, fish, rodents, dogs and non-human primates. I'm not aware of any other. I'll change this to the only dietary intervention if nobody objects. --88.70.183.176 (talk) 09:23, 31 August 2009 (UTC)

Methionine restriction.--Nutriveg (talk) 18:14, 31 August 2009 (UTC)

Walford and Weindruch

Great catch, that's interesting why credit was only given to the student... although he was still the one to report them? Maybe teachers do that to give their underlings a better chance at success later, when they are satisfied. Tyciol 16:38, 14 February 2006 (UTC)

Benefits only the young?

There's oodles of evidence that CR benefits exist at all ages. Too rapid introduction of CR is the problem in the few studies that don't show that. This section should be removed. /--Borgipedia 18:36, 19 July 2006 (UTC)

this does not only benefit the young my grandmother is 85 years old and has had type 1 diabeties all her life. my fiance is 19 and he was diagnosed with type 1 diabeties at the age of 2. so it can get to any one at any age. some people like to say they wont get it but u never know who will wind up with any form of diabeties. thaks for listeni nng to me . beckah 2-17-09 —Preceding unsigned comment added by 68.249.143.152 (talk) 19:51, 17 February 2009 (UTC)

Names of researchers

This article quotes the names of many of the researchers, but I couldn't find any reference to the David Sinclair mentioned in Sir2. is this a mistake? --apers0n 15:33, 28 July 2006 (UTC)

Not sure what you mean — that no one has yet found the reference to the claim attributed to him? /--Borgipedia 15:56, 28 July 2006 (UTC)

Well I looked at the studies attributed to him and couldn't find his name mentioned anywhere, but wasn't sure if Sinclair is a notable person in the world of CR, in which case there should be a reference to him. It is unusual to name the researchers in a reference article like this unless describing a historical sequence of e.g. the first person to discover the benefits of CR was... or a notable person (such as someone who has their own biography on Wikipedia - see Dave Sinclair - Keyboard player from Caravan). A better place for the names of researchers is in the references/notes section.

Example: "Studies by Mark P. Mattson, PhD, chief of the National Institute on Aging's (NIA) Laboratory of Neurosciences, and colleagues have found that..." - surely the occupation of Mark P. Mattson, PhD belongs on the page for the NIA? --apers0n 06:30, 29 July 2006 (UTC)

Martin Brookes comment

To Mccready: Why do you want Brookes comment here in the intro? The intro paragraph introduces CR, and (like CR) makes no claims about single or multiple causes of aging. Thanks in advance. --Borgipedia 09:36, 21 August 2006 (UTC)

needs context Mccready 08:52, 22 August 2006 (UTC)

What do others think? Anyone? Seems like a bizarre thing in this intro paragraph. Mccready: perhaps you can add more than your two words here? The question of the absence or presence of single causes of aging seems like weird "context." What do you mean? Thanks. --Borgipedia 14:51, 22 August 2006 (UTC)

You asked me to discuss. I did. You didn't. I'm removing it. Please justify, here, putting back before you put it back. --Borgipedia 15:36, 5 September 2006 (UTC)

CR is one of the most prominent techniques for allegedly reducing aging in humans (please remember that it is not proven in humans). As such, we owe it to the readers of this article to provide some context. There is nothing weird or bizarre about this comment from a scientist. I'll replace now. Mccready 19:58, 5 September 2006 (UTC)

Your quotation makes the point, indeed, stresses the point, that aging doesn't have one single cause. What does that have to do with the introductory paragraph in this article about CR, which (para. and article) rightly makes no claims about the number of causes of aging? /--Borgipedia 15:16, 6 September 2006 (UTC)

Are you being dense or playing at wikilawyering? CR claims by implication if not directly that a major cause of aging is related to calorie intake. It's got nothing to do with any number. I'm reverting. Mccready 15:05, 11 September 2006 (UTC)

Please read the article, and/or read up on CR. You don't know enough about it to understand how to edit this article. CR itself doesn't "claim" anything, but advocates of CR believe that CR can affect various aspects of aging. No one argues that calorie intake is a direct cause of aging. I see from your other posts you have an axe to grind. Grinding it here is probably not a good idea. James Randy-ism isn't apposite here. Thanks. /--Borgipedia 18:01, 11 September 2006 (UTC)

Body temperature relation?

Lowering the body temperature of mice resulted in significant longevity increase:

http://www.livescience.com/animalworld/061102_cool_mice.html

From the article:

"Past studies have shown lifespan can be extended in animals by cutting down on the calories in their diets. Interestingly, this method also lowers body temperature. "The mechanisms mediating the increased lifespan in the 'cool mice' may be similar to those of calorie restriction," Conti speculated."

--Cheese Sandwich 13:36, 4 November 2006 (UTC)

Article Organization (species section)

This is either a note to myself for when I have more time, or a request for others watching this page. Is it useful to have the section "effects on different organisms?" Several sections are stubs, and amount basically to "this species has been shown to live longer." The exception currently is the section on Rats, but clearly most of that material should be moved to the section "Why might CR effect longevity?"

It seems to me a more useful organization might be "Effects Of CR" and then, rather then divide it into species subtopics, divide it into outcome subtopics. "Increased longevity" - Longevity has been verified in mice, rate, c. elegans, etc.; "Decreased rates of Cancer", "Improved cardiovascular function", "Lower free radical damage" - etc., in each case noting in which species the benefit has been verified. This would take some work - a meta-analysis of what's been published, and a fair amount of referencing - but it strikes me as a much more useful organization. Each section could also, of course, note when the benefit has not been observed. Comments? SJS1971 11:41, 9 November 2006 (UTC)

CR vs. lean

In current human practice, what is the difference between CR and being skinny/lean/lowbodymass/smallwaisted? Is the only difference getting good nutrition? Is there any difference? Can you be doing CR and still maintain a relatively high weight? Should you? Does practicing CR imply being low-energy and exercising little? Or imply the opposite? This should all be clearly addressed in a section of the article. And there also needs to be a good wiki article on the plain relation of body mass to longevity, with a prominent See also link from here. 69.87.203.106 14:17, 18 November 2006 (UTC)

This article is on caloric restriction, which involves eating less food. CR does not address weight or any of a bunch of other health issues, so they should not be covered in this article. —Preceding unsigned comment added by Warren Dew (talk • contribs) 19:22, 20 October 2009 (UTC)

Biosphere Two significance

I think it should be mentioned in the article the results and link to Calorie Restriction obtained through Biosphere Two by Roy Walford. Evidence can be cited here:

• http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12023257&dopt=Abstract - Peer-reviewed Journal Article
• http://www.lef.org/protocols/lifestyle_longevity/caloric_restriction_01.htm - Direct link to Calorie Restriction

The eight people living in Biosphere 2, an enclosed ecosystem, underwent involuntary caloric restriction during their 2-year stay because they were unable to grow enough food for their needs. They consumed 1800 calories per day during the first 6 months and 2200 calories thereafter. Their diet was nutrient rich and high in vegetables. Body weight decreased by 15 percent and serum cholesterol dropped 38 percent. Blood pressure fell from an average of 110/74 millimeters of mercury (mm Hg) to 90/59 mm Hg. A group outside Biosphere 2, who ate without restriction but who took the same nutritional supplements as those inside Biosphere 2, did not exhibit these same positive health alterations

-- Walford RL et al 2002

• http://news.bbc.co.uk/2/hi/sci/tech/specials/anaheim_99/260611.stm - BBC coverage

The Biosphere project unintentionally became a significant study on calorie restriction on humans in a completely isolated environment - an important control variable.

P.S. Sorry for the alignment of the quote, it's from the second external link I put up. -- Permafrost 03:21, 10 February 2007 (UTC)

Intermittent Fasting

There should be a new article specifically on Intermittent Fasting, because that has proven to be a superior method of life-extension in animals, and perhaps humans. The benefits of intermittent fasting seem to be independent of Calorie Restriction (CR). For example, fasted mice eating as much as controls showed superior results to those eating only 60% as much (40% CR). This brings into question the whole theory of CR, because the same benefits (and more) can be had WITHOUT restricting calories. —Preceding unsigned comment added by 65.80.77.27 (talk • contribs) 10:27, 9 April 2007

In this study there was another group which ate as much as the intermittent fasting (IF) group, called the pair-fed (PF) group. This group also showed "superior results" (only in the experiment where neurotoxins are directly injected into the brain...), but the study is thin on details about this group. They didn't let the mice live long enough to be able to say how the lifespans compared. Intermittent fasting is certainly not proven to be a superior method of life extension. And please if you write about such studies, only look at the original paper, not at some media gossip. Icek 11:18, 22 July 2007 (UTC)

Maybe he's referring to a different study? I see no "media gossip" in the following;

That IF feeding was more effective than either LDF or PF in protecting neurons from KA-induced damage demonstrates that the IF-feeding schedule itself is neuroprotective independent of overall caloric intake.

The whole point of IF over CR is mainly the benefit of increased insulin sensitivity, since some estimate as much as 25% of the U.S. population is suffering /dying from 'metaboic syndrome'.

"In contrast, at the end of the study the body weights of mice maintained on the IF diet or PF on a daily basis were only slightly below those of the AL-fed group (Fig. 1b). A prominent physiological change that occurs in mammals maintained on reduced-calorie diets is increased insulin sensitivity, which often is reflected in decreased fasting plasma levels of glucose and insulin (17). Fasting serum concentrations of glucose and insulin in mice fed AL in the current study averaged 150 mg/dl and 3,400 pg/ml, respectively (Fig. 2 a and b). The concentrations of glucose and insulin were decreased significantly, to similar amounts, in mice maintained on either LDF or IF regimens with glucose and insulin concentrations dropping to 100 mg/dl and 700–1,100 pg/ml, respectively (Fig. 2). That similar changes are seen in IF and LDF groups in the current study suggests that despite an overall calorie intake similar to mice fed AL, IF has similar effects on circulating glucose and insulin levels." Proc Natl Acad Sci U S A. 2003 May 13; 100(10): 6216–6220. http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=156352--EinRand (talk) 11:26, 6 July 2008 (UTC)

Policy on sourcing

I reverted an unsourced addition of content, and the editor who made it then reverted it back: [1]. I try to follow a one-revert rule, so I will not revert it again. I asked the editor for more clear sourcing, but my request was refused: [2]. According to Wikipedia:Verifiability "Articles should only contain material that has been published by reliable sources. Editors adding or restoring material that has been challenged or is likely to be challenged, or quotations, must provide a reliable published source, or the material may be removed." Is a citation to "Charlie Rose - calorie restriction" satisfactory detail for this material, or should we raise the bar on the article sourcing to comply with WP:CITE and WP:RS? Buddhipriya 07:53, 15 July 2007 (UTC)

When I type that in to google it gives a youtube copy as the very first hit and the same under yahoo; with all due respect, you have no case whatsoever under the wikipedia policies. You also have no power to unilaterally raise or lower bars on individual articles within the wikipedia.WolfKeeper 15:48, 15 July 2007 (UTC)

Precise amount of intake calories

A normal amount of kcal a person consumes is around 2800-3000kcal/day, is it possible to include in this article how much is consumed with this caloric restriction diet/day? —Preceding unsigned comment added by 81.244.193.44 (talk) 08:58, August 29, 2007 (UTC)

I agree. How can we have an article about calorie restriction and not mention how low the number of calories need to be to be considered "restricted".Pasado (talk) 00:14, 27 January 2009 (UTC)

I notice this still seems to be an issue with the article. What is it, 50%? 90%? I thought I saw studies using both figures for animals. --Gwern (contribs) 07:42 21 July 2009 (GMT) 07:42, 21 July 2009 (UTC)

There is no precise amount. One study on the effects of calorie restriction on elderly men and women used a 30% reduction compared to controls. Maybe explaining that there isn't enough research available yet to recommend a calorie intake in humans would help. —Preceding unsigned comment added by 128.36.164.147 (talk) 22:26, 26 December 2009 (UTC)

Genetics Inaccuracies

"Sir2 or "silent information regulator 2" is a longevity gene in baker's yeast cells that extends lifespan by suppressing DNA instability (see Sinclair and Guarente, Cell, 1997).[10] In mammals Sir2 is known as SIRT1. Recent discoveries have suggested that the gene Sir2 might underlie the effect of CR. In baker's yeast the Sir2 enzyme is activated by CR, which leads to a 30% lifespan extension."

These statements are entirely inaccurate. Sir2 is not a "longevity gene", it has multiple responsibilities. Of primary importance is its role in cell division. My understanding of the literature, which is by no means extensive, is that CR increases Sir2 expression. Sir2, I believe, has 7 mammalian homologs SIRT1-7. SIRT1 is active in the nucleus. SIRT3 is an inter membrane mitochondrial enzyme which may play a role in regulation of thermogenesis, it is found primarily in the brown adipocye mitochondria. I don't know about the rest.

As for the 30% part, I have no idea what studies are showing and thus have no objections except for the lack of a citation. I intend to remedy my own lack of citations for above statements. —Preceding unsigned comment added by Backwardtoes (talk • contribs) 22:19, 25 October 2007 (UTC)

CRON-diet article

A new article is to come for the CRON-diet (which uses calorie restriction)

The Calorie Restriction with Optimal Nutrition-diet is a low calorie, high nutrition- diet which practices the limiting of dietary energy intake in the hope that it will improve health and retard aging.

This first line already shows that more low-high diets exist and can be used with the okinawa diet article aswell.

Dont have time to look up the references, found it in the health plan book of roy walford. Look into it and change article.

KVDP (talk) 15:14, 1 February 2008 (UTC)

The CRON-diet in practice

a new section would need to describe the CRON-diet in practice. It is to include: standard CR diet which is proposed (and still safe) features 5-25% CR restriction (it can go up to 60% in theory yet no longer safe). Standard diet recomendations are usually to begin with 1800 calories/day. Further work out may happen as this is a guideline(biospherians ate 1800 calories/day, yet had to work physically hard). basal metabolic rate of person cannot be accuratly measured (thus trial and error method is to be followed aldough trough the fat percentage some indications may be given on the amount of calorie intake a person must follow, as body fat should not drop below (6% for a man and 10% for a woman) KVDP (talk) 10:43, 2 February 2008 (UTC)

Catabolisis

I removed an incorrect sentence stating that heart damage is more related to ketosis than to low calorie catabolisis. Any time the body release Adrenocorticotropic hormone, in response to stresses (low caloric intake is an example of such a stress), fats, and more importantly proteins in the body are broken down to ensure blood sugar is kept high. The problem is that proteins are broken down indiscriminately, leading to organ damage, and to the type of bloating seen in starving children when blood osmotic proteins are broken down, and lymph fluid functions improperly. I remember learning this in Grade 12 Biology, and I am certain about its correctness. 24.65.42.159 (talk) 17:58, 10 July 2008 (UTC)

Removing Negative effects Increased mortality

I am removing the negative effects of increased mortality. The study cited there is studying individuals based solely on BMI, and is no way a controlled experiment between CR and non-CR individuals. As pointed out in the topic "CR vs. Lean" quite a few people can be underweight and be on a non-CR diet, so it is important to note the distinction that low BMI does not connotate a CR individual. Masparasol (talk) 01:51, 12 December 2008 (UTC)

smokers, and people with cancer, can be lean but not on a CR diet and not healthy.

one twinkie and 3 stiff drinks a day will make you thin, but not healthy.

Studies reporting that thin people were unhealthy mostly overlooked that people who are unhealthy in a way that makes them thin tend to omit that fact on life insurance applications. Studies using the original data and date of death often fail to account for the omission of smoking (or cancer or other health conditions) and conclude erroneously that being thin by itself is bad. When adequate controls for unhealthy unreported habits are instituted, thin tends to be good for health, down to very thin. Of course anorexics die because there IS such a thing as too thin, but it is a skeletal thin that finally destroys the immune system, far below the thin ordinary people are familiar with or would aspire to. —Preceding unsigned comment added by 68.165.11.64 (talk) 01:54, 11 July 2009 (UTC)

Quality of "Yeast" section

The paragraph following headline "Yeast" is of poor quality. There are many grammatical and spelling mistakes. —Preceding unsigned comment added by 76.200.187.2 (talk) 09:43, 18 February 2009 (UTC)

About the Controversy: Here's an Example of CRON Calculations

Some of the pro-vegetarian stuff makes it nearly impossible to get adequate nutrition with CRON. I consider raw foodism, and vegetarianism to be distractions on the road to CR. Let's do some simple math.

A woman might normally eat 2300 Calories per day. Most CR folks cut their intake (over time) to be 30% less than it was. So that's a touch over 1600 Calories per day. That's like being on Weight Watchers for the rest of your life, except, you never go back to "maintenance".

The question is, can a person get enough nutrition under that restriction? The answer is a resounding YES and in fact, she will have better nutrition than the average American gets in their whole life. ...as long as she pays attention to the nutrients. I'll try to prove it to you with an example. Some good round numbers for what our fictitious woman needs is the following (check for yourself on the USDA "Recommendations for Americans" site - I've overestimated her needs):

Per-Day:

Protein 100g x 4Cal/g = 400 Cal
Carbs 150g x 4Cal/g = 600
Fiber 30g x 2Cal/g = 60
Fat 40g x 9Cal/g = 360

So total intake if you had paid attention to getting these amounts in your food every day is 1420 Cal. So that's the minimum you can eat per day if you want to keep these healthy levels of macronutrients. Macronutrients are the only source of significant Calories in food. Try to think of a vitamin that has calories. Omega-3? That's a fat. Vitamin D? Well, it's dissolved in fat, so there are a few calories there, but it's about 25 Cal max for a good supplement.

Now, even if you're not on this diet, check your diet out, and see if you are getting this much of everything right now. I bet not. Sometimes people panic over the nothing. Nobody would say that Weight Watchers is a fad or a starvation diet. Nor that people on it aren't getting enough nutrition. So why get bothered about this?

—Preceding unsigned comment added by 72.92.130.230 (talk) 16:35, 8 July 2009 (UTC)

Studies reporting CR ill effects were flawed by reliance on truthfulness of health- and life-insurance applicantions

Smokers and people with cancer can be lean but not on a CR diet and not healthy.

One Twinkie and 3 stiff drinks a day will make you thin, but not healthy.

Studies failing to report that thin people were unhealthy mostly overlooked the inclusion of people who were unhealthy in a way that made them thin. Smokers and people with cancer tend to omit such facts on life insurance applications. Studies using their original applications and date of death often failed to account for the omission of smoking (or cancer or other health conditions) and to conclude erroneously that being thin by itself was bad. But when adequate controls for unhealthy unreported habits or conditions were instituted and the data were re-analyzed, thin proved to be good for health, down to quite thin. Of course anorexics die because there IS such a thing as too thin -- a skeletal thin that finally destroys the immune system, far below the thin resulting from, e.g., 30% calorie restriction (with high-quality diet). See Chron diet for more on the kind of high-quality diet actually thought to provide benefits. —Preceding unsigned comment added by 68.165.11.64 (talk) 02:04, 11 July 2009 (UTC)

Total Starvation vs. Calorie Restriction

I do not feel qualified to actually put this in the article, so I will offer it here for consideration for someone else to take up.

There is an interesting study conducted jointly by Poland's Department of Gastroenterology, Institute of Internal Medicine, Medical Academy of Pozna, Poland , and the Department of Nephrology. They seem to conclude that starvation diet and calorie restricted diets both lower weight in obese people, BUT... starvation diet tends to cause weight loss by reducing both fat and non-fat (ie, muscle) tissue, whereas Calorie Restricted diet tended to produce weight loss in fat tissue only.

link: http://www.springerlink.com/content/h3145861v1r37m24/

70.184.23.23 (talk) 05:03, 29 July 2009 (UTC)klw

Rhesus macaques study not so positive

Currently, the Primates section is entirely pro-CR. This does not reflect the actual studies, though. In particular, the rhesus macaque study returned a negative result on the primary outcome: the difference in deaths between the two groups was not statistically significant. It was made to be statistically significant in the reports by excluding deaths that the researchers considered to be non-age related. More criticisms:

http://junkfoodscience.blogspot.com/2009/07/calorie-restrictive-eating-for-longer.html Astgtciv (talk) 15:26, 18 August 2009 (UTC)

Final results have not yet been reported for the macaque study, and likely will not be for at least a decade. The interim results that you refer to didn't reach statistical significance on deaths yet because too many of the macaques are still alive, even in the unrestricted group. If you look at the actual numbers in the paper, it seems virtually certain that they will confirm the expected CR results once there has been enough time for more of the macaques to die off.Warren Dew (talk) 19:30, 20 October 2009 (UTC)

Then I recommend removing the reference until the time at which the study actually gives significant results. If the results are not significant, then they are not significant. Trends in studies are often wrong. The description in the main text implies the study is finished and the results presented are final. Astgtciv (talk) 19:23, 23 November 2009 (UTC)

I'm sorry to be so negative about this study, when I agree it will probably show dramatic results on the primary outcome (lifespan) in the future. However, at the moment, it does not. As Feynman said, "The first rule is not to fool yourself....", and so I think we need to stick with what the paper actually says currently. Right now, the main article says that the paper shows that CR "blunts aging and significantly delays the onset of age related disorders such as cancer, diabetes, cardiovascular disease and brain atrophy" (in the monkeys). However, they do not provide p-values for all of those, and I don't believe they would all be significant. In particular, from the figures in the paper, I highly doubt they show a statistically significant effect on cardiovascular disease (4 controls and 2 CRs) and doubt they show a significant effect on cancer (8 controls and 4 CRs). By contrast, they show a very strong effect on diabetes (16 controls showed problems, none of the CR monkeys did), but they didn't provide a p-value. They group all age-related diseases together for calculating a p-value, so the diabetes/pre-diabetes probably has a very large influence on that. The main article also says, "at the 20 year point, 80% of the calorically restricted monkeys were still alive, compared to only half of the controls", but fails to note that this result is not statistically significant (or if it is, the p-value is not given in the paper). Astgtciv (talk) 15:39, 24 November 2009 (UTC)

Inital paragraph

Shouldn't the first paragraph at least define what the article is about? Right now it just immediately launches into health benefits before defining what Calorie Restriction means. Reads like someone advertising their lifestyle choice. —Preceding unsigned comment added by 131.51.128.21 (talk) 14:19, 7 October 2009 (UTC)

It's been fixed, very timely and effective editing. —Preceding unsigned comment added by 131.51.128.21 (talk) 07:35, 8 October 2009 (UTC)

List of "negative effects" (now "health concerns") appears to be misguided

The section on negative effects of calorie restriction is misleading. The effects the section describes are caused by malnourishment, not calorie restricted diets. Calorie restricted diets aren't ones that are so restrictive that patients starve or die. So mortality, starvation, and abnormal hair growth should be removed from the list of negative effects of calorie restriction. Those effects have not been shown to be associated with diets that researchers call calorie restricted diets, at least judging by the citations in the "negative effects" section.

Also, this sentence should be removed: "However, that relation seems to be age-specific since another study, when analyzing people older than 65, those who were underweight had a higher dementia risk than normal or overweight people.[17]" The sentence cites a study that did not involve calorie restriction to call into question the results of a study that did involve calorie restriction.128.36.164.147 (talk) 22:13, 26 December 2009 (UTC)

I renamed it to "health concerns". There's no single procedure for a calorie restriction diet, so calorie restriction may imply in malnourishment described in that section that's important to keep the article balanced.--Nutriveg (talk) 22:25, 26 December 2009 (UTC)

But they're not health concerns of calorie restricted diets. None of the references involve diets considered to be calorie restricted diets. They're effects of malnutrition.

I think that if these statements must be in the article, the article should clarify the difference between malnourishment and calorie restriction. Malnourishment results from eating too little. Calorie restriction is eating less for health benefits.

It may be helpful to note in the article that excessive calorie restriction would lead to malnutrition, but that should be obvious to anyone reading the article.128.36.164.147 (talk) 22:35, 26 December 2009 (UTC)

Low BMI and malnutrition can be the result of a low calorie diet depending on the individual (lean) and how it implements that restriction (how much). So these are concerns that should be mentioned. It would be obvious if it was a standardized diet, but it isn't.--Nutriveg (talk) 22:57, 26 December 2009 (UTC)

To support these claims, there should be references to studies in which diets that researchers called a calorie restricted diet caused abnormal hair loss, starvation, or death in humans. 128.36.164.147 (talk) 23:07, 26 December 2009 (UTC)

These are concerns not causes. This is a source (see "Unhealthy Excessive Calorie Restriction") but there are probably others around.--Nutriveg (talk) 23:19, 26 December 2009 (UTC)

A restrained note that it's possible that even moderate calorie restriction may be harmful to certain groups, like underweight people, might be useful. But nothing in the article you linked to justifies three prominent subheadings proclaiming that calorie restriction may cause starvation, death, and abnormal hair loss.

Maybe clarifying what the article means by calorie restriction at the front end would be useful. We might say that for the purposes of this article, calorie restriction a dietary regimen that restricts calorie intake without causing malnutrition.128.36.164.147 (talk) 23:54, 26 December 2009 (UTC)

Both views should balanced, a single phrase isn't enough in face of the claimed benefits.

That would be WP:OR there isn't just such definition of CR.--Nutriveg (talk) 23:59, 26 December 2009 (UTC)

Actually, in the article you just linked to: "Subsequently, data have shown that calorie restriction, defined as a reduction in calorie intake below usual ad libitum intake without malnutrition, slows aging and increases maximum life span in different species." It's a reasonable definition for this article. Also, giving equal weight to less persuasive positions for the sake of "balance" is silly.128.36.164.147 (talk) 00:12, 27 December 2009 (UTC)

Also, there are far too many headings in the section. I propose that what's there now be consolidated under three headings: lack of essential nutrients, binge eating disorder, and potential malnourishment. Under the potential malnourishment section, we can note that overzealous calorie restriction can lead to malnourishment, and then note that abnormal hair growth and even death can result.

Also, the "attenuation of age-related sarcopenia" should not have a heading at that level, and it should not be in positive effects on humans section, because the study involves rhesus monkeys.

I'm happy to make these changes if they won't be summarily reverted.128.36.164.147 (talk) 22:42, 26 December 2009 (UTC)

I like the headings because they keep content organized, specially when someone else adds new information. It's not a problem of overzealous calorie restriction but a problem of the diet itself that may not apply no everyone (or just a few) and is not standardized. Those are not caused by CR, but are concerns and higher mortality is only a association not a cause.

You can move the monkey study. I don't think other changes are necessary.--Nutriveg (talk) 22:57, 26 December 2009 (UTC)

The headings overemphasize the importance of the claims, which hardly belong in the article, since they aren't supported by references to studies that involved calorie restriction. 128.36.164.147 (talk) 23:03, 26 December 2009 (UTC)

Ok, you can edit that but try not to remove content.--Nutriveg (talk) 23:06, 26 December 2009 (UTC)

"Binge eating" claim has no foundation - move for immediate removal.

The statement that calorie restriction can lead to binge eating is both absurd and lacking any sort of citation, as noted in the article itself. Anybody even remotely educated in calorie restriction knows that with a CR diet comes a smaller stomach; while the typical fast-food lover may indeed binge-eat after consuming 800 or so calories in a day, this is hardly even an issue with actual practitioners of calorie restriction. Indeed, this statement merely seems to be somebody's personal opinion with no basis behind it. Let's do the article a favor and remove it. 67.60.38.138 (talk) 07:29, 8 June 2010 (UTC)

I agree that it needs a reference, but it is not the least absurd. Calorie restriction is not only a "lifestyle" but also "a common measure found in several dietary regimens" and many overweight persons on a low calory diet break their diet by binge eating. Lova Falk talk 16:05, 8 June 2010 (UTC)

The source cited actually says specifically that caloric restriction puts people at risk for binge eating only if they are already bingers. This article is not about yo-yo dieters or bingers. The article is about sustainable reductions of caloric intake in animals, including humans, and the increases in lifespan (reasonably conjectured in the case of humans, plausibly demonstrated in some other species) that result. Yakushima (talk) 15:54, 1 November 2010 (UTC)

Negative effects section(s)

I understand there are a lot of proponents, but as someone not as informed, and reading teh article for educational purposes, I'm detecting a pretty strong bias the toward calorie restriction camp. This seems especially evident in the negative effects section(s) where it seems there is a caveat or apologetic attached to each potential concern, that seems aimed at explaining it away. I know this, like other diet and health issues, can be contentious and people feel strongly about it. But let's try to keep the POV to a minimum. I'd love to be bold and edit, but not having as much depth in the topic as I think it deserves, I'd rather suggest someone else do it. I think that section really needs some pruning for apologetic language. Let is stand on its own, as the benefits section should stand on its own. This is not supposed to be a puff piece on CR, nor is it supposed to be propaganda against it. It's natural to want to defend something you believe in, but this is not a persuasive article, it's an encyclopedic entry, and should be a neutral as possible.Jbower47 (talk) 17:59, 25 March 2011 (UTC)

A potential inlusion of a Calorie Restrictionin the media' section (Sources to sort and remove irrelevant or less credible)

• "Eat, Fast and Live Longer" – (BBC Horizon Documentary) (This documentary goes into Calorie Restriction and Fasting interviewing various researchers.)

Original Write up on the documentary: "Michael Mosley has set himself a truly ambitious goal: he wants to live longer, stay younger and lose weight in the bargain. And he wants to make as few changes to his life as possible along the way. He discovers the powerful new science behind the ancient idea of fasting, and he thinks he's found a way of doing it that still allows him to enjoy his food. Michael tests out the science of fasting on himself - with life-changing results" http://www.bbc.co.uk/programmes/b01lxyzc

• “The Science of Fasting” (TV Documentary on ARTE) (Although not specifially all about Calorie Restriction this is a documentary on fasting mentions and shows some Calorie Restriction program from the Buchinger Clinic in Überlingen.)

http://www.youtube.com/watch?v=sNdWCZWpjxU http://www.buchinger.com/en/news-stories/latest-news/newsinhalt/detail/2012/april/24/Scientific-documentary-on-fasting8232.html http://www.viadecouvertes.fr/pages/en/reference.php?id=113

Potential edited summary write up on documentary: "The Franco-German television channel ARTE aired a documentary on fasting. The program examines the potential role to be played by fasting in the healthcare systems of industrialized countries, including in the treatment of diabetes, hypertension, obesity, and cancer, and as a way to reduce the potential overconsumption of pharmaceuticals. The film spotlights five major centers of fasting: In Germany, the film profiles the Buchinger Clinic in Überlingen, as well as the Department of Natural Medicine at the Charité University Hospital in Berlin. At the Centre National de Recherche Scientifique in Strasbourg, France, Professor Yvon Le Maho and his team investigate instinctive fasting in the animal kingdom."

Original Write up on the documentary from one of the sources: "Fasting as medical therapy is now experiencing a revival thanks to the groundbreaking research by Professor Valter Longo in the areas of anti-aging and cancer therapy. The Franco-German television channel ARTE aired an excellent scientific documentary on fasting. Produced by the renowned French documentary duo, Sylvie Gilman and Thierry Vincent de Lestrade, the program examines the potential role to be played by fasting in the healthcare systems of industrialized countries, including in the treatment of diabetes, hypertension, obesity, and cancer, and as a way to reduce the explosive overconsumption of pharmaceuticals. In presenting fasting as a proven complementary therapy, the film spotlights five major centers of fasting science and therapy: In Germany, the film profiles the Buchinger Clinic in Überlingen, as well as the Department of Natural Medicine at the Charité University Hospital in Berlin. At the Buchinger Clinics in Überlingen and Marbella, more than 250,000 fasting therapies have been medically supervised in the last 60 years. The Buchinger Clinics are Europe’s largest clinics for therapeutic fasting and have profound experience in the medical applications of fasting. At the Centre National de Recherche Scientifique in Strasbourg, France, Professor Yvon Le Maho and his team use the latest technology to investigate instinctive fasting in the animal kingdom. Hundreds of publications have shown that the ability to fast is a natural physiological adaptation of humans and animals to life on the planet Earth. The availability of food changes from winter to summer, and therefore a succession of eating and fasting periods is absolutely normal. Doctors and clinics in Russia have amassed extensive knowledge and experience in therapeutic fasting, including a wealth of scientific publications during the Soviet era that have never been translated and remain virtually unknown outside Russia. In the United States, there is a tradition of fasting in the alternative scene. "

• some miscelaneous sources in media from the web:

• Eat Less, Live Longer? http://www.genomenewsnetwork.org/articles/2004/07/09/calorierestriction.php

• Feast, fast and reduce risks http://www.latimes.com/features/health/la-he-eat10dec10,1,883044.story?coll=la-headlines-healthI

• Routine Periodic Fasting Is Good for Your Health, and Your Heart, Study Suggests, ScienceDaily (Apr. 3, 2011) http://www.sciencedaily.com/releases/2011/04/110403090259.htm

• Fasting Weakens Cancer in Mice http://www.sciencedaily.com/releases/2012/02/120208152254.htm

• Fasting could help fight cancer, By Roger Highfield, Science Editor http://www.telegraph.co.uk/science/science-news/3337872/Fasting-could-help-fight-cancer.html

• Fasting and cancer, Starving the Beast, The Economist, Feb 9th 2012, 22:02 by T.C. http://www.economist.com/blogs/babbage/2012/02/fasting-and-cancer

• Fasting can help protect against brain diseases, scientists say: Claim that giving up almost all food for one or two days a week can counteract impact of Alzheimer's and Parkinson's http://www.guardian.co.uk/society/2012/feb/18/fasting-protect-brain-diseases-scientists

• A few medical sources to sort through for potential inclusion of some of the more credible ones (some will be less credible or less current than others, some are more on fasting and not caloric restriction so perhaps to be sorted seperately into fasting wikipedia page if any of wikipeida community wish to submit changes):

1. Fasting cycles retard growth of tumors and sensitize a range of cancer cell types to chemotherapy. Lee C, Raffaghello L, Brandhorst S, Safdie FM, Bianchi G, Martin-Montalvo A, Pistoia V, Wei M, Hwang S, Merlino A, Emionite L, de Cabo R, Longo VD. Andrus Gerontology Center, Department of Biological Sciences, Norris Cancer Center, University of Southern California, 3715 McClintock Avenue, Los Angeles, CA 90089-0191, USA. http://www.ncbi.nlm.nih.gov/pubmed/22323820 Abstract: Short-term starvation (or fasting) protects normal cells, mice, and potentially humans from the harmful side effects of a variety of chemotherapy drugs. Here, we show that treatment with starvation conditions sensitized yeast cells (Saccharomyces cerevisiae) expressing the oncogene-like RAS2(val19) to oxidative stress and 15 of 17 mammalian cancer cell lines to chemotherapeutic agents. Cycles of starvation were as effective as chemotherapeutic agents in delaying progression of different tumors and increased the effectiveness of these drugs against melanoma, glioma, and breast cancer cells. In mouse models of neuroblastoma, fasting cycles plus chemotherapy drugs--but not either treatment alone--resulted in long-term cancer-free survival. In 4T1 breast cancer cells, short-term starvation resulted in increased phosphorylation of the stress-sensitizing Akt and S6 kinases, increased oxidative stress, caspase-3 cleavage, DNA damage, and apoptosis. These studies suggest that multiple cycles of fasting promote differential stress sensitization in a wide range of tumors and could potentially replace or augment the efficacy of certain chemotherapy drugs in the treatment of various cancers.

2. Fasting and cancer treatment in humans: A case series report. Fernando M. Safdie,1,6 Tanya Dorff,2,3,6 David Quinn,2,3 Luigi Fontana,4 Min Wei,1 Changhan Lee,1 Pinchas Cohen,5 and Valter D. Longo1 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2815756/ Abstract: Short-term fasting (48 hours) was shown to be effective in protecting normal cells and mice but not cancer cells against high dose chemotherapy, termed Differential Stress Resistance (DSR), but the feasibility and effect of fasting in cancer patients undergoing chemotherapy is unknown. Here we describe 10 cases in which patients diagnosed with a variety of malignancies had voluntarily fasted prior to (48-140 hours) and/or following (5-56 hours) chemotherapy. None of these patients, who received an average of 4 cycles of various chemotherapy drugs in combination with fasting, reported significant side effects caused by the fasting itself other than hunger and lightheadedness. Chemotherapy associated toxicity was graded according to the Common Terminology Criteria for Adverse Events (CTCAE) of the National Cancer Institute (NCI). The six patients who underwent chemotherapy with or without fasting reported a reduction in fatigue, weakness, and gastrointestinal side effects while fasting. In those patients whose cancer progression could be assessed, fasting did not prevent the chemotherapy-induced reduction of tumor volume or tumor markers. Although the 10 cases presented here suggest that fasting in combination with chemotherapy is feasible, safe, and has the potential to ameliorate side effects caused by chemotherapies, they are not meant to establish practice guidelines for patients undergoing chemotherapy. Only controlled-randomized clinical trials will determine the effect of fasting on clinical outcomes including quality of life and therapeutic index.

3. ‘Short-term therapeutic fasting (7 days) in the treatment of chronic pain and fatigue syndromes--well-being and side effects with and without mineral supplements’ - Michalsen A, Weidenhammer W, Melchart D, Langhorst J, Saha J, Dobos G. Department of Internal Medicine V and Integrative Medicine, Kliniken Essen Mitte, Am Deimelsberg 34 a, 45276 Essen, Germany. 2002 http://www.ncbi.nlm.nih.gov/pubmed/12232494

4. ‘The short-term (7 days) effects of fasting on the neuroendocrine system in patients with chronic pain syndromes.’ - Michalsen A, Schneider S, Rodenbeck A, Lüdtke R, Huether G, Dobos GJ. Department of Internal Medicine V and Integrative Medicine, Kliniken Essen Mitte, Am Deimelsberg 34 a, 45276 Essen, Germany. 2003 http://www.ncbi.nlm.nih.gov/pubmed/12608732

5. 2010 / CellCycle / Fasting and differential chemotherapy protection in patients / Rafaghello, Prof. Valter Longo, et al./ DOI: 10.4161/cc.9.22.13954

6. 2010 / Trends in Pharmacological Sciences / Calorie restriction and cancer prevention: metabolic and molecular mechanisms / Prof Valter D. Longo and Luigi Fontana / DOI: 10.1016/j.tips.2009.11.004

7. 2007 / PNAS / Starvation‐dependent differential stress resistance protects normal but not cancer against high‐dose chemotherapy / Lizzia Raffaghello, Prof. Valter Longo, et al. / DOI: 10.1073"pnas.0708100105

8. 2011 / Oncogene Research / Fasting vs dietary restriction in cellular protection and cancer treatment: from model organisms to patients / Changhan Lee and Prof. Valter Longo / DOI: 10.1038/onc.2011.91

9. ‘Medically supervised water-only fasting in the treatment of hypertension.’ Goldhamer A, Lisle D, Parpia B, Anderson SV, Campbell TC. Center for Conservative Therapy, Penngrove, Calif, USA. 2002 http://www.ncbi.nlm.nih.gov/pubmed/11416824

10. ‘Medically supervised water-only fasting in the treatment of borderline hypertension.; - Goldhamer AC, Lisle DJ, Sultana P, Anderson SV, Parpia B, Hughes B, Campbell TC. TrueNorth Health Center, Rohnert Park, CA 2002 http://www.ncbi.nlm.nih.gov/pubmed/12470446

11. ‘Prolonged fasting (7-21 days) as a method of mood enhancement in chronic pain syndromes: a review of clinical evidence and mechanisms.’ - Michalsen A. Immanuel Hospital Berlin, Department of Internal and Complementary Medicine, Institute of Social Medicine, Epidemiology and Health Economics, Charité-University Medical Centre, Germany. 2010 http://www.ncbi.nlm.nih.gov/pubmed/20425196 Abstract: Periods of deliberate fasting with restriction to intake of solid food are practiced worldwide, mostly based on a traditional, cultural, or religious background. Recent evidence from clinical trials shows that medically supervised modified fasting (200-500 kcal nutritional intake/day) with periods from 7 to 21 days is efficacious in the treatment of rheumatic diseases and chronic pain syndromes. Here, fasting is frequently accompanied by increased alertness and mood enhancement. The beneficial claims of fasting are supported by experimental research, which has found fasting to be associated with increased brain availability of serotonin, endogenous opioids, and endocannabinoids. Fasting-induced neuroendocrine activation and mild cellular stress response with increased production of neurotrophic factors may also contribute to the mood enhancement of fasting. Fasting treatments may be useful as an adjunctive therapeutic approach in chronic pain patients. The mood-enhancing and pain-relieving effect of therapeutic fasting should be further evaluated in randomized clinical trials.

12. ‘Caloric restriction in primates and relevance to humans.’ - Roth GS, Ingram DK, Lane MA. Laboratory of Neurosciences, Gerontology Research Center, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224, USA. 2001 http://www.ncbi.nlm.nih.gov/pubmed/11795522 Abstract: Dietary caloric restriction (CR) is the only intervention conclusively and reproducibly shown to slow aging and maintain health and vitality in mammals. Although this paradigm has been known for over 60 years, its precise biological mechanisms and applicability to humans remain unknown. We began addressing the latter question in 1987 with the first controlled study of CR in primates (rhesus and squirrel monkeys, which are evolutionarily much closer to humans than the rodents most frequently employed in CR studies). To date, our results strongly suggest that the same beneficial "antiaging" and/or "antidisease" effects observed in CR rodents also occur in primates. These include lower plasma insulin levels and greater sensitivity; lower body temperatures; reduced cholesterol, triglycerides, blood pressure, and arterial stiffness; elevated HDL; and slower age-related decline in circulating levels of DHEAS. Collectively, these biomarkers suggest that CR primates will be less likely to incur diabetes, cardiovascular problems, and other age-related diseases and may in fact be aging more slowly than fully fed counterparts. Despite these very encouraging results, it is unlikely that most humans would be willing to maintain a 30% reduced diet for the bulk of their adult life span, even if it meant more healthy years.

13. ‘The impact of religious fasting on human health.’ Trepanowski JF, Bloomer RJ. Cardiorespiratory/Metabolic Laboratory, The University of Memphis, Memphis, TN 38152, USA. http://www.ncbi.nlm.nih.gov/pubmed/21092212 Abstract: Greek Orthodox Christians fast for a total of 180 - 200 days each year, and their main fasting periods are the Nativity Fast (40 days prior to Christmas), Lent (48 days prior to Easter), and the Assumption (15 days in August). Some of the more favorable effects of these fasts include the lowering of body mass, total cholesterol, LDL-C, and the LDL-C/HDL-C ratio. The Biblical-based Daniel Fast prohibits the consumption of animal products, refined carbohydrates, food additives, preservatives, sweeteners, flavorings, caffeine, and alcohol. It is most commonly partaken for 21 days, although fasts of 10 and 40 days have been observed. Our initial investigation of the Daniel Fast noted favorable effects on several health-related outcomes, including: blood pressure, blood lipids, insulin sensitivity, and biomarkers of oxidative stress. This review summarizes the health-specific effects of these fasts and provides suggestions for future research.

14. ‘The Effects of Caloric Restriction on Health and Longevity.’ Green JL, Sawaya FJ, Dollar AL. Emory University, 49 Jesse Hill Jr Drive SE, Atlanta, GA, 30303, USA 2011 Abstract: OPINION STATEMENT: There is increasing evidence that restricting caloric intake may have considerable health benefits in humans. Significant evidence in non-primate animals demonstrates that caloric restriction increases average and maximal life span. However, historically, caloric intake reduction in humans has been involuntary and accompanied by poverty, malnutrition, poor sanitation, and a lack of modern health care. As a result, caloric restriction in people typically has been accompanied by a reduction of both average and maximal life span. Conversely, improvements in standards of living usually are accompanied by an increased food supply and resultant improved health and longevity. The majority of the world is now in a new era where an abundance of caloric intake and its associated obesity are causing widespread chronic illness and premature death. What would happen if one were to institute caloric restriction with high-quality nutrition within an environment of modern sanitation and health care? This review argues that improved health and improved average life span would quite likely result. A lengthening of maximal human life span with this combination is perhaps possible but by no means certain.

15. A.J.Carlson and F. Hoelzel, “Nutrition, Senescence and Rejuvenescence”. Public Health Reports Vol.67 No.2. February 1952 Chicago.

16. H.L.Taylor, “American Journal of Physiology”. pp143-148 1945.

17. A.J.Carlson and F. Hoelzel, “Apparent Prolongation of Lifespan of Rats by Intermittent Fasting”. Journal of Nutrition, 31:363 1946.

18. Sergius Morgulis, “Fasting and Undernutrition”. University of Nebraska, E.P. Dutton, New York 1923.

19. A.J.Carlson, “The Control of Hunger in Health and Disease”. University of Chicago 1916.

20. Margaret M. Kunde, “The After Effects of Prolonged Fasting on the Basal Metabolic Rate”. Journal of Metabolic Research 1923, 3, 399 – 449.

21. R.H. Weindruch, J.A.Kristie, K.Cheney and R.L.Walford, “The Influence of Controlled Dietary Restriction on Immunologic Function and Ageing”. Federation Proceedings U.C.L.A. 389:2007 (1979)

22. ‘Caloric restriction in C57BL/6J mice mimics therapeutic fasting in humans.’ - Mahoney LB, Denny CA, Seyfried TN. Biology Department, Boston College, Chestnut Hill, MA, USA. 2006

23. ‘Clinical Aspects of the Ketogenic Diet’ - Adam L. Hartman, Eileen P. G. Vining, The John M. Freeman Pediatric Epilepsy Center, Johns Hopkins Medical Institutions, Baltimore, Maryland U.S.A. http://onlinelibrary.wiley.com/doi/10.1111/j.1528-1167.2007.00914.x/full

24. ‘Fasting increases the in vivo gene delivery of AAV vectors.’ - Moulay G, Scherman D, Kichler A., Genethon, Evry, France. http://www.ncbi.nlm.nih.gov/pubmed/21207763

25. ‘Greek Orthodox fasting rituals: a hidden characteristic of the Mediterranean diet of Crete.’ Sarri KO, Linardakis MK, Bervanaki FN, Tzanakis NE, Kafatos AG. Department of Social Medicine, University of Crete, School of Medicine, PO Box 2208, Iraklion 71003, Greece. 2004 http://www.ncbi.nlm.nih.gov/pubmed/15333159

26. ‘Incorporation of fasting therapy in an integrative medicine ward: evaluation of outcome, safety, and effects on lifestyle adherence in a large prospective cohort study.’ - Michalsen A, Hoffmann B, Moebus S, Bäcker M, Langhorst J, Dobos GJ. Department of Integrative and Internal Medicine V, Kliniken Essen-Mitte, and Complementary and Integrative Medicine of the Alfred Krupp von Bohlen und Halbach Foundation, University Duisburg-Essen, Essen, Germany. 2005 http://www.ncbi.nlm.nih.gov/pubmed/16131283

27. Short-term dietary restriction and fasting precondition against ischemia reperfusion injury in mice.’ Mitchell JR, Verweij M, Brand K, van de Ven M, Goemaere N, van den Engel S, Chu T, Forrer F, Müller C, de Jong M, van IJcken W, IJzermans JN, Hoeijmakers JH, de Bruin RW. Department of Genetics, Erasmus Medical Center, Cancer Genomics Center, Dr. Molewaterplein 50, 3015 GE, Rotterdam, The Netherlands. 2010 http://www.ncbi.nlm.nih.gov/pubmed/19878145

28. ‘A trial of fasting cure for PCB-poisoned patients in Taiwan.’ 1984 Imamura M, Tung TC. http://www.ncbi.nlm.nih.gov/pubmed/6422746

29. ‘Brain Metabolism during Fasting’ O. E. Owen, A. P. Morgan, H. G. Kemp, J. M. Sullivan, M. G. Herrera, and G. F. Cahill, Jr., Elliott P. Joslin Research Laboratory, Department of Medicine, Harvard Medical School, the Cardiovascular Unit, the Peter Bent Brigham Hospital, and the Diabetes Foundation, Inc., Boston, Massachusetts 1967 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC292907/?page=6

30. ‘Brief case reports of medically supervised, water-only fasting associated with remission of autoimmune disease.’ Fuhrman J, Sarter B, Calabro DJ. Hunterdon Medical Center, Flemington, NJ, USA. 2002 http://www.ncbi.nlm.nih.gov/pubmed/12126162

31. There is also a highly dubious case in India of a man called Prahlad Jani whom claims to have lived without not just food but also water for years. Observation studies of Jani have been conducted, one in 2003 and one in 2010, both involving Sudhir Shah, a neurologist at the Sterling Hospitals in Ahmedabad, India. http://en.wikipedia.org/wiki/Prahlad_Jani SpringSummerAutumn (talk) 14:56, 20 November 2012 (UTC)

What is BUD CR?

Under "Possible contraindications", the author states: "Both animal and human research suggest BUD CR..." but nowhere else in the article is BUD CR defined, and I can't even find any reference to that term with a quick Google on "BUD CR calorie restriction". Bhami (talk) 19:29, 18 December 2012 (UTC)

You are quite right. I went back in History to find if it was explained previously, but I gave up at 1 december 2008. Anyway, I just remove the incomprehensible BUD. Lova Falk talk 08:40, 26 December 2012 (UTC)

Using WikiBlame, I found out that it was indeed vandalism/graffiti. --Florian Blaschke (talk) 22:57, 16 January 2016 (UTC)

What's with all the vague "Results are being periodically published."??

When the intro and the article body talk about the University of Wisconsin study, they just say "Results are being periodically published".

Why so secretive??

There's very little research on CR, and only two primates, so why not say something about the results that have been published so far?

I haven't read the results, so I can't add anything. I can just note that as a reader, this seems strange. Gronky (talk) 07:28, 29 January 2013 (UTC)

recent edits by Lufontana

In the past few days User:Lufontana added a bunch of content based on studies done on Washington University, citing a primary source in which data were published on a study of 18 CR patients and 18 controls. At Wikipedia we base content on secondary sources, not primary ones as per WP:PSTS and for health-related information, this is even more important, as per WP:MEDRS. What we need is a review article that discusses this study and puts it in context. I was tempted to completely delete the content, and perhaps we should, but for now I reduced the amount of content to give it appropriate WP:WEIGHT - it based only a primary source and we should not rely on it very much. Jytdog (talk) 13:22, 4 December 2013 (UTC)

Primary sources

This article is basically all primary sources. These need removing. We should be using secondary sources per WP:RS. Doc James (talk · contribs · email) (if I write on your page reply on mine) 23:13, 4 July 2014 (UTC)

nicely done! thanks. Jytdog (talk) 23:28, 4 July 2014 (UTC)

There are lots of secondary sources such as this one https://www.ncbi.nlm.nih.gov/pubmed/24883306 Still a lot of work to do. Doc James (talk · contribs · email) (if I write on your page reply on mine) 00:07, 5 July 2014 (UTC)

"Effects on Humans"

As User:Jytdog has highlighted, there is the beginning of an edit war in the "effects on humans" that should be preempted. The metabolic effects and effects on biomarkers of CR in humans are ipso facto effects of on humans, and were located there for a very long time before they were puzzlingly moved, and then (in what I would characterize as overly-strict adherence to the "primary source" exclusion) deleted altogether; I've provided proper secondary sources, and they are in line with the full statement from Spindler's review that "we certainly know that restricting calories can improve human health and reduce many risk factors for life-limiting diseases in people" even if "about the true quantitative benefits of CR for life extension in humans are simply unknown, but " (which has also, puzzlingly, been cut when it actually contextualizes the summary in the article and should help resolve any ambiguity about the "effects." These sections therefore belong in the section on "effects in humans."

I have no problem with moving all of the "effects on humans," including the potential negative effects, into the "research" section, but separating them seems to me to be fairly clearly arbitrary. --Mikalra (talk) 19:21, 28 August 2014 (UTC)

thanks for talking. are you familiar with WP:MEDRS? Thanks Jytdog (talk) 19:25, 28 August 2014 (UTC)

Yes:

"Ideal sources for such content includes literature reviews or systematic reviews published in reputable medical journals, academic and professional books written by experts in the relevant field and from a respected publisher, and medical guidelines or position statements from nationally or internationally recognised expert bodies. Primary sources should generally not be used for medical content."

My sources conform to that guideline, and that the sections are therefore suitably placed as 'effects on humans.' I am genuinely puzzled as to why they were moved in the first place, and why you are moving them now that suitable sourcing has been provided.

--Mikalra (talk) 19:54, 28 August 2014 (UTC)

(exhale). What we have are some small clinical studies that are suggestive-- research; not knowledge of a clinical intervention that has been proven to be safe and effective. Considering calorie restriction as an intervention - like ibuprofen or knee replacement... We know that giving someone with a headache an ibuprofen, or replacing a degraded knee with an implant, is relatively safe and effective, and to what extent, for each. You have no MEDRS-compliant source that says our state of knowledge about calorie restriction is there - what we have is research that is still underway. Jytdog (talk) 20:22, 28 August 2014 (UTC)

Er ... but I didn't claim that CR has been proven to be safe and effective, and neither do the sources I cite, nor the original or revised text of the article. As indicated, these are short- and medium-term effects on disease risk factors and metabolism, and long-term health and lifespan effects in humans are yet unknown. It is simply discussing the "Effects in Humans," and these are accurately portrayed.--Mikalra (talk) 21:59, 28 August 2014 (UTC)

Changes in surrogate markers are not health effects. Doc James (talk · contribs · email) (if I write on your page reply on mine) 22:19, 28 August 2014 (UTC)

Again, I didn't say they were health effects. The section is called "effects on humans." Reductions in BMI aren't health effects either, nor are most of the other things in the "effects on humans" section (and many of those are hypothetical). The BMI-mortality association isn't even from clinical trials, but from epidemiology, but has been put in the "effects on humans" section; the Minnesota starvation experiment was clearly research. Again, there is no evident reason why some of the best-studied "effects on humans" are separated from others, or particularly why the "effects on humans" should be almost entirely deleterious ones (or ones hypothesized to be deleterious).--Mikalra (talk) 22:32, 28 August 2014 (UTC)

sorry i was being a obtuse. in health related articles, for interventions, we put what is known (like we know ibupfrofen and knee replacements) in sections like "health effects" or the like. Things we are still trying to understand, we put in sections called "research." that is why doc james shifted the content you added to the Research section. With health interventions, the gold standard for knowing is one or more sufficiently powered double blinded randomized clinical trials, not epidemiological studies and not small clinical trials. does that make sense? Jytdog (talk) 22:52, 28 August 2014 (UTC)

Would we all agree, then, to also put the other materials that we are still trying to understand — which include all, or nearly all, of the effects discussed in the current "Effects on humans" section — into "Research"? --Mikalra (talk) 23:45, 28 August 2014 (UTC)

I reckon! there may be some more tweaking but generally yes thank you for talking! it is rare. Jytdog (talk) 00:31, 29 August 2014 (UTC)

All right. In the process, I'd like to suggest rearranging the overall structure of the article, which seems strange now and would seem even stranger after moving (most of) that one section. May I suggest instead:

History

Research

.1 Rodents

.2 Primates

.3 Yeast

.4 Caenorhabditis elegans

.5 Humans

.5.1 Biomarkers for cardiovascular risk

.5.2 Biomarkers for cancer risk

.5.3 Negative effects

.6 Activity level

.7 Stereotyped behavior

.8 Aggression

Mechanisms

.1 Hormesis

.2 Evolution

.3 Chromatin and PHA-4

.4 Free radicals and glycation

.5 Reduced DNA damage

Calorie restriction mimetics

.1 Sirtuins

Objections

.1 No benefit to houseflies, overfed model organisms

.2 Hypothesized Confounding by Activity Levels

.3 Insufficient calories and amino acids for exercise

.4 Does calorie restriction only benefit the young?

.5 Negligible effect on larger organisms

--Mikalra (talk) 03:49, 29 August 2014 (UTC)

That seems to be a valid structure. You may want to have a look at WP:MEDMOS for interventions, if you are not aware of it. I am also pinging Doc James who has edited this article as well, before you invest the work to make that happen... Jytdog (talk) 03:55, 29 August 2014 (UTC)

The current structure follow WP:MEDMOS much better than this proposal does so I would appose the change. Doc James (talk · contribs · email) (if I write on your page reply on mine) 03:57, 29 August 2014 (UTC)

I have just made some edits that group all of the research in specific animal (including human) species together at the bottom, putting the other material on concerns and confounders that was interspersed amongst it in a separate secion; I believe that this still retains the structure per WP:MEDMOS as Jytdog and Doc James prefer. Idon't foresee an objection, but thought a heads-up would be in order.Mikalra (talk) 19:31, 14 September 2014 (UTC)

As Doc James said, changes in surrogate health markers are not health effects. Still, a reader without a medical background would find the phrase in the article, "long-term effects [of Calorie Restriction] are unknown," confusing when we do know so much about how Calorie Restriction effects surrogate markers, and this information has been summarized adjacent to the statement that we know nothing of the effects of Calorie Restriction on humans. Simply changing, "effects," to, "disease outcomes," or the like would help the understanding of the general reader. makeswell (talk) 21:02, 24 October 2014 (UTC)

Molecular mechanism behind health benefits of dietary restriction identified

Perhaps you should add this somewhere on the page: http://www.hsph.harvard.edu/news/press-releases/molecular-mechanism-behind-health-benefits-of-dietary-restriction-identified/

--ThalèsWasHere (talk) 18:12, 13 January 2015 (UTC)

That would be PMID 25542313 which is primary research and so not really in line with our medical sourcing guidelines. Alexbrn ^{talk|contribs|COI} 18:23, 13 January 2015 (UTC)

Additionally, this is only one of many, many putative "key molecular mechanisms behind the health benefits of dietary restriction," identified in one new study from one lab: the number of such are legion. Also, the actual effect on lifespan (rather than protection from liver injury) has only been shown in yeast, worms, and flies so far; to make it genuinely noteworthy, we'd want to see it replicated in mammals.

Mikalra (talk) 20:26, 13 January 2015 (UTC)

Reversion of 2016-09-16

Alexbrn reverted my edit on the basis of "material based on non-WP:MEDRS. I would like to undo this reversion. With the exception of the "Austad and Kristan, 2003" paper, which is primary source, the other citations all meet MEDRS criteria.

Additionally, the reversion also reversed edits to material that clarified findings without changing sources from status quo ante. User:Mikalra 14:11, 15 September 2016 (UTC)

I don't think there were MEDRS. For example, take the first paper you cite[3] - a piece of primary research. In general, that article is in really bad shape. I think most of the existing "Research" section can be deleted as it's a collection of primary material. Would be happy to discuss on the article's Talk page. Alexbrn (talk) 13:16, 15 September 2016 (UTC)

That's an example of my second point. I didn't add the JAP citation, and your reversion therefore didn't remove it from the page: I edited the text of that section without changing the sources. My new sources wre in the section I retitled "Obese controls" which you reverted to "Critique."Mikalra (talk) 14:15, 15 September 2016 (UTC)

It a unreliable source (rat experiment) and should be removed. You added text implying a human health effect which compounded things. Really, there's not much point discussing wording when - at a basic level - the article is full of junky sourcing and need a huge prune. Alexbrn (talk) 14:21, 15 September 2016 (UTC)

Research sources

Hi Zefr. I have trouble with the section on Humans under Research. Three sentences with three references that have been cited a sum total of 148 times. Can we agree to throw out Everitt and Le Couter? Their paper seems to be written as an introduction and reads much like a high school report. My objection is that they belittle years of life, "it is estimated that long-term CR to prevent excessive weight gain could add only 3–13 years to life expectancy." A drug that could add that much to a cancer patient's life would be a bestseller. And according to them the Okinawans used to live "only" 4 years longer. A small empire was founded on those same 4 years. I think that last sentence is repetitive. Why not just omit the whole thing? We ought to build up the sources for these statements instead of diluting the message. -SusanLesch (talk) 17:50, 9 November 2017 (UTC)

The 3 sentences seem reasonably accurate and worthwhile to state, but in a search for better sources, it becomes obvious that CR is difficult, if not impossible, to study and quantify for health or longevity benefits. Without absolute control of subjects, similarly frustrated as in feeding and nutrition clinical trials, CR must be a challenging condition to control, hence the absence of high-quality, large-scale clinical research and comprehensive systematic reviews on human results. The 3 references used are also > 7 years out of date, and therefore inadequate for the encyclopedia. --Zefr (talk) 18:12, 9 November 2017 (UTC)

May I suggest this reference? Calorie restriction in humans: An update (2017). May I ask why this article doesn't link to CALERIE? Why doesn't it mention Human Vitality and Efficiency Under Prolonged Restricted Diet (Benedict et al. 1919)? Internet archive has a free copy. The Gale Encyclopedia of Diets (editor is Kristen Key, 2nd edition, copyright 2013) has an article on calorie restriction. I'm still digging. -SusanLesch (talk) 22:48, 9 November 2017 (UTC)

Thanks, but I think all these sources would be categorized as "low-quality" and unusable under WP:MEDASSESS. --Zefr (talk) 23:03, 9 November 2017 (UTC)

There's a tertiary source and a systematic review (granted not reviewing randomized controlled trials). A link to CALERIE and a mention of the first major study are both intended to make this encyclopedia more complete (neither is a source). It is questionable why they aren't here already. But you choose not to answer that. -SusanLesch (talk) 23:45, 9 November 2017 (UTC)

Confilict of interest

I need to declare a possible conflict: the first author of this review is one of my teachers plus I enrolled in her class for next semester. Because she isn't teaching us this subject, while I knew she was among the authors of the 2015 study, I did not know she had written the review that is possibly a very good source. After looking into COI, evidently this might not be a problem. This is a first for me. Apologies for taking so long to declare. -SusanLesch (talk) 22:46, 9 November 2017 (UTC)

No worries. Thanks for being open about this. Doc James (talk · contribs · email) 07:41, 10 November 2017 (UTC)

Subject and objective

One problem with this article is that the subject of all these experiments switches from humans to animals and back and forth again. A second problem is that the objective of CR seems to sway in the wind. Some places, CR is intended to prolong life, and in others CR reduces risk factors for disease, and in others CR is a weight loss tactic. Do you think this is a fair assessment and do you think the article can be improved? -SusanLesch (talk) 19:09, 10 November 2017 (UTC)

1 Health effects humans
   1.1 Risks of malnutrition
2 Mechanisms mice, humans, rodents, yeast
   2.1 Temperature 
   2.2 Hormesis
   2.3 Evolution
   2.4 Chromatin and PHA-4
   2.5 Reduced DNA damage
   2.6 Sirtuin-mediated mechanism
3 Caloric restriction mimetics humans, yeast, worms, flies, fish, mice
   3.1 Sirtuins
4 History one human generalized to other species
5 Research humans, primates and humans, rodents, yeast (pretty good!)
   5.1 Humans
   5.2 Primates
   5.3 Rodents
   5.4 Yeast
6 Effects rodents, monkeys, monkeys, animals, animals
   6.1 Activity levels
   6.2 Stereotyped behavior
   6.3 Aggression
   6.4 Obese controls

To this I would add that two sentences are gibberish. Under Mechanisms, "the mechanism by which caloric restriction works is still not well understood". I don't believe anything can "work" unless we know its objective. Second, I changed the second sentence in the lead, ""Low" can be defined relative to the subject's previous intake before intentionally restricting calories, or relative to an average person of similar body type." to "Reduce" can be defined.... Either way, we would need to specify what [something] is "relative to an average person of similar body type." -SusanLesch (talk) 21:43, 10 November 2017 (UTC)

We generally keep headings short. I do not see this extension as an improvement. Yes the mechanisms are proposed ones. We do not even know if CR really has the benefits claimed. Doc James (talk · contribs · email) 05:45, 11 November 2017 (UTC)

@Doc James: I'm not sure you understand what the TOC above signifies. It is a summary, top to bottom, of the topics in this article as they switch from humans to other animals and then back and forth. It's not a proposed extension of the headings in the article. My questions for you are above the TOC. Now you've raised another question though. This article will need to admit more recent sources, some of which will state positive things about CR. I don't believe the selective quotation of Fontana 2007 speaks very well for Wikipedia. -SusanLesch (talk) 00:30, 12 November 2017 (UTC)

Unknown, unknown, unknown

Hi DocJames and Zefr. Can you please explain why this article needs to have three statements that the longterm effects of moderate CR on humans is unknown? DocJames writes in his edit summary that he is restoring "The most important part of the article." Perhaps we share a fear for life of a person with low BMI who might read something that might encourage them to restrict calories. Speaking as a new member of Wikiproject:Medicine, I am sorry but the net effect of three statements is that this article is biased against the idea of caloric restriction in humans. -SusanLesch (talk) 20:58, 7 November 2017 (UTC)

You said: "... three statements that the longterm effects of moderate CR on humans is unknown?" Could you specify those 3 statements? Edited the section on human research, and rearranged the content for a more logical order. See what you think. --Zefr (talk) 00:17, 8 November 2017 (UTC)

@Zefr: The 3 statements (before your edits):

• "In humans, the long-term health effects of moderate caloric restriction with sufficient nutrients are unknown." (in the lead)
• "In humans, the long-term health effects of moderate caloric restriction with sufficient nutrients are unknown." (the first sentence after the lead)
• "Studies have been conducted to examine the effects of calorie restriction with adequate intake of nutrients in humans; however, long-term effects are unknown." (under Research > Humans)

It will take me a day or so to read your sources. -SusanLesch (talk) 01:46, 8 November 2017 (UTC)

@DocJames: I am waiting for your reply. -SusanLesch (talk) 15:27, 8 November 2017 (UTC)

A space will be needed between "Doc" and "James" for the ping to work. The lead is supposed to repeat the body of the text. I do not see it as undue. Doc James (talk · contribs · email) 12:41, 9 November 2017 (UTC)

The third mention should probably be reworded atleast "however, long-term effects are unknown" should be more like "long-term studies have not been done" as it is in the research section, not the health effects section. Galobtter (talk) 13:59, 9 November 2017 (UTC)

Aha, thank you for the correction on spelling, Doc James. You haven't answered my question though. (I still owe Zefr my take on your sourcing for the section Research > Humans.) Why is this article biased against calorie restriction? You keep saying, over and over, that the effect of longterm moderate CR on humans is unknown. Yet you selectively cite sources that say CR can be beneficial to omit that fact. And you selectively admit primary material that supports your view and remove primary material to the contrary. I doubt this is intentional but this article needs work. -SusanLesch (talk) 16:45, 9 November 2017 (UTC)

It is normal to be skeptical. It is up to those proposing the claim to present the research not the other way around. And extra ordinary claims require extra ordinarily good sources. Doc James (talk · contribs · email) 07:42, 10 November 2017 (UTC)

@Doc James: You cite the Minnesota Starvation Experiment but you give page 1113 for every instance (the citation is reused for a total of four citations). What are the correct citations and why for the love of Pete don't you use them? I tried to follow one in particular, under "Biomarkers for cardiovascular risk," where you say, "Similar effects were also seen during a "natural experiment" in Biosphere 2,[81] and in subjects in the “Minnesota Starvation Experiment” during World War II." I was disappointed to find the actual Appendix cited is about Methods. Also, this is a primary source. Thus my criticism above that you remove and include primary material selectively. May I suggest They Starved So That Others Be Better Fed: Remembering Ancel Keys and the Minnesota Experiment or some other secondary source? -SusanLesch (talk) 22:01, 10 November 2017 (UTC)

Under Health effects, you say, "The authors of a 2007 review of the caloric restriction literature warned that "[i]t is possible that even moderate calorie restriction may be harmful in specific patient populations, such as lean persons who have minimal amounts of body fat."

In their paper, Fontana and Klien say under conclusions, "Calorie restriction in adult men and women causes beneficial meta- bolic, hormonal, and functional changes, but the precise amount of calorie intake or body fat mass associated with optimal health and maximum longevity in humans is not known. In addition, it is possible that even moderate calorie restriction may be harmful in specific patient populations, such as lean persons who have minimal amounts of body fat."

This is the instance where I find you guys selectively quoting somebody who thinks CR is a good thing but omitting that fact. My problem now is that Zefr will not accept a more recent updated review by Fontana, "Calorie restriction in humans: An update" (2017) (he thinks it is "low quality"). So please at least rewrite this to reflect the man's real words. -SusanLesch (talk) 22:22, 10 November 2017 (UTC)

When one editor doubts the interpretation of WP:MEDRS by another, that first editor can 1) make a revision and cite the source, Most et al. to see if it stands, or 2) take the issue to a discussion board, either WT:MED or WT:MEDRS, where other editors will chime in. My response here was only my interpretation that the quality for human evidence in the Most review was inadequate to include. --Zefr (talk) 23:49, 10 November 2017 (UTC)

Hi @Zefr: Maybe you would do me a favor. The following list comes from Das et al. 2017 ("Nutrition modulation of human aging: The calorie restriction paradigm") which I am careful not to add to the article. Can you say if each one of the five is a true statement or is false?

SusanLesch: responses below following each point, although I don't have access to the full Das article, so will be brief. --Zefr (talk) 16:32, 12 November 2017 (UTC)

• CR's primary aim is: "attenuating or delaying the onset of physiological and metabolic effects of aging and associated disabilities." (p. 148)

False. Keeping it simple, the initial goal and effect of CR are on weight loss, the numerous mechanisms of which I sense are the more interesting and scientifically challenging events to define, before anti-aging mechanisms are addressed.

• "Additionally, it is unknown whether different CR regimes, such as alternate day fasting (ADF), intermittent fasting (IF) or time restricted feeding (TRF) have differing effects on healthspan or lifespan (Patterson et al., 2015)." (p. 150)

True. There is insufficient human research to discern such effects.

• CALERIE-2 (2015) found no reduction in core body temp or in resting metabolic rate

True and false, respectively. In the CALERIE study published here, Table 1 and 5th paragraph of the Discussion, the authors report no effect on body temperature, and a significant decrease in resting metabolic rate only in the first year.

• T3 levels determine basal metabolic rate (p. 154)

Partly true. T3 has numerous physiological roles (explained in its WP article), including an effect on metabolic rate.

• CR reduces T3 and IGF1 activity, and increases cortisol and adiponectin levels (p. 154, and other markers that page; I stopped at the word "controversial.")

True for T3. According to the CALERIE article, CR reduced T3 by 16% in the first year and 22% in the 2nd year. I saw no results there for the other biomarkers.

Thank you. I don't have the necessary credentials to know one way or the other but these seemed like solid pieces of information. -SusanLesch (talk) 00:20, 12 November 2017 (UTC)

The measurements you've highlighted with these questions are biomarkers for changes resulting from CR, but there is insufficient knowledge about their precise roles, alone or integrated, for reducing body weight and extending life. The Das study and CALERIE (concluded in 2013) were works in progress, so would be defined as inconclusive primary research, and likely not usable in the article. As indicated by Doc James below, the article is rated as a C class and needs more and better sources, which are not available currently. As I feel we have discussed this enough, I am moving on to other editing and don't wish to be involved in further details here. --Zefr (talk) 16:32, 12 November 2017 (UTC)

Where do I cite the "Minnesota Starvation Experiment"? Doc James (talk · contribs · email) 06:00, 11 November 2017 (UTC)

@Doc James: Sorry my use of you refers to the group of people who answer questions here and who edit the article. One might say you are stewards (WP:STEWARDSHIP). In the English language the word is both singular and plural so I should have rephrased. I use you apart from "we" because I can't endorse this article as written. The search function in your browser is a good way to find the citations. -SusanLesch (talk) 16:12, 11 November 2017 (UTC)

Who says I endorse it as written either? It is less bad than it once was, but it is a C class for a reason. Doc James (talk · contribs · email) 09:21, 12 November 2017 (UTC)

Thank you, disapproval noted, Doc James. Let's address the four or five things given here that would help. I'm going to work on the History section which currently stretches a Fontana paper out of recognition. -SusanLesch (talk) 14:54, 12 November 2017 (UTC)

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critique

You have an excellent references page listed. I verified a few of the citations and they all seem to go to legitimate sources. I don't feel like there is any plagarism, everything appears to be re phrased in own words. The only negative or take a way is that I don't feel like everything is cited per say in the article that should be.Mss200424 (talk) 02:40, 21 June 2018 (UTC)

Outdated article with primary or animal references

I was surprised to read this entry, as it does not reflect at all the current knowledge nor institutional recommendations (such as US dietary guidelines 2015-2020 or AHA or NICE). It mostly includes either adverse effects, or primary/animal studies. I would recommend updating the article starting from the institutional guidelines. I also find it very confusing the distinction that was made between this entry and the "calorie restriction for dieting" redirecting to Dieting, as currently this entry is exactly written to cover calorie restriction for dieting.

Furthermore, dieting is not just calorie restriction: there are several diets that do not involve calorie restriction but nutrients balance modification (eg, Mediterranean diet), and others that involve only a different timing (meals timing, such as Intermittent fasting or strategically timing meals and snacks), which does not necessarily involve losing weight!. Dieting can indeed be done for different purposes: weight loss is the most common intervention indication, but it can be for CVD or other biomarker risk decrease (see Weight loss which nicely explain that different view).

Anyway, all of these points are also covered by the references above. About the adverse effects, sure it is necessary to describe them, but there are some major inaccuracies given the current state of knowledge. For example, it is now known that calorie restriction and weight loss are the best treatment for NAFLD, including lean NAFLD (individuals that are lean but have a fatty liver), thus opposing what is written in the entry. Same for obesity and diabetes). That is not to say that everyone should do calorie restriction (even if the US dietary guidelines suggest to restrict calories intake to prevent CVD and obesity -- thus not in the sense of continuous dieting but in the sense of managing one's own calories intake -- but note that for obesity they advise to do continuous dieting), but there are now clearly accepted indications for some pathologies, mainly the metabolic syndrome ones. Furthermore, the AHA evaluated there is "high" evidence that there is a long-term beneficial effect (and weight loss sustainability) of caloric restriction dieting for the treatment of obesity. Even for pregnancy, there are now systematic reviews showing limiting weight gain (and thus doing calorie intake control or even mild calorie restriction) improves outcomes for both the mother and child (see Management of obesity and more specifically:[4][5]).

Thus, I would suggest to:

1. rewrite the article based on the good quality references above (and if possible update with systematic reviews - I saw but didn't retain lots of them when looking for intermittent fasting). Some additional pertinent references might be found in the quite closely related articles Management of obesity, Obesity, Dieting, NAFLD, Intermittent fasting.
2. make this entry focused on "voluntary calorie restriction" (thus the diet, since the involuntary one is covered in Eating disorder), and make the Dieting article an overview of the various goals and ways to do dieting (as it partially does currently, but is not focused enough).

Meanwhile, since I have nearly exhausted my spare time allowed for editing, I will add a Template:Update banner to try to raise attention and foster discussion. Thank you for reading and participating --Signimu (talk) 22:48, 5 October 2019 (UTC)

References

---

Update: I rewrote the lede, I hope this can provide a good start for the rest of the article. --Signimu (talk) 03:09, 6 October 2019 (UTC)

Thanks to Zefr for cleaning up and removing the banner --Signimu (talk) 17:58, 22 October 2019 (UTC)

Unexplained edits that defy logic

Either wikipedia and the editor who doesn't even read the existing content before deleting someone's addition start to act professionally, or I'm considering starting my own wikipedia type site that follows some logic.

Updating this complaint, Dec 21,2019, as Zefr once again reverted a significant addition to mice.

00:17, 22 December 2019‎ Zefr talk contribs‎ 25,454 bytes -498‎ Reverted 1 edit by 67.243.247.88 (talk): Speculative; unconstructive (TW) undo Tag: Undo

A major finding of the 2017 report on the CR monkey studies was that the previous assumption that the effect of early onset CR observed in mice was not the case for primates. It was so not speculative that it was currently in the Primate section. I only repeat it in the Mice section because the mouse study is still important in estimating potential human lifespan extension. But one aspect of that mouse study, the front loaded benefits of early onset CR is not only not supported by the monkey study, the monkey study finds no benefit for younger CR. And yet, you still need to know about the mice study, for the still valid estimates of life extension, and to understand the significance of the finding in the monkey report.

curprev 23:25, 21 December 2019‎ 67.243.247.88 talk‎ 25,952 bytes +498‎ Some cosmetic edits to make section clearer and easier to read, and updated information on mice with signifcant observations made about mice/rodent data from more recent study.

undo Tag: Visual edit "Mice: fringe content with a weak source;" What? Are you insane? Weak source? Rozalyn M. Anderson? Are you saying the article is made up and you think https://www.alzforum.org is involved in an elaborate hoax, and the author, Gwyneth Dickey Zakaib, can't be trusted, or perhaps didn't even write the article?

Here is the information I'm trying to get into the mice section:

“That’s not something we could have predicted based on rodent studies,” said Anderson. In mice, the earlier scientists restrict diet, the longer animals live (for a review, see Speakman and Hambly, 2007).

Anderson is Rozalyn M. Anderson, a lead author of "Caloric restriction improves health and survival of rhesus monkeys" in Nature Communications. Of course mice studies are central to any discussion of Calorie restriction. Previous to my edits, the information in Humans was incorrect and misleading, and very out of date. Spefically it discounted Calorie resstriction by hiding the fact a study was comparing it to 20th Century public health improvements like the development of antibiotics and a decrease in accidents. Either get with the program or be called out as a bunch of crazies who suppress knowledge. — Preceding unsigned comment added by 67.243.247.88 (talk) 03:18, 19 December 2019 (UTC)

Do I need to make a new section or table, differences between Human, Primate, Mice CR?

In advance of what would unquestionably be an unethical undo for umpteeth time of truth with untruth, I'm proposing creating a new section comparing Human vs Primate and Mice CR. The current goal of information provided in the Mice section for Calorie Restriction is to highlight how it aids and informs studies of human CR. Every reference to mice is only made in so far as it provides insight into human CR, human health, and human longevity. The same is true for primates. A counter example would be dog CR, where CR could provide either insight into human CR, or could provide a way to prolong health and lifespan of beloved pets. Perhaps a Dog entry is needed. — Preceding unsigned comment added by 2604:2000:1742:83ED:4C8:FE5F:EADD:2DB1 (talk) 20:11, 30 December 2019 (UTC)

Overview of this Talk

In order to save considerable time for anyone stumbling upon this page, here are the current issues being discussed. Please note that technically entries should appear in chronological order, so the last entry is on the bottom. Obviously an Overview (and the linked outline) would not. There are three viewpoints expressed here. One from October 2019, with suggestions for a general rewrite, another from December 2019 (from this editor), which aside from exposing a comparison of CR to 20th century introduction of antibiotics, reduction in accidents, and cvd, introduced a section on mice, and a third, from a very active editor, that keeps undoing mice information. If you are here, the current discussion is then, do we want mice study info in the CR article? There is what I would characterize as illogical, inconsistent, contraditory, and fabricated claims about sources, relevance, and what the term outdated means, used to justify the undos. The reader is invited to read the Talk, follow the sources, and decide for themselves. — Preceding unsigned comment added by 2604:2000:1742:83ED:B944:9FFE:9936:EC32 (talk) 23:40, 31 December 2019 (UTC)

Outdated research using mice

Hard to see the value of this section using sources 13-15 years old. The 2017 review PMID 28977341 discusses there are too many design differences in animal research, indicating the CR studies on rodents are too preliminary to include, and are not translatable to humans, WP:MEDANIMAL. Removed from the article as below for discussion, if warranted. --Zefr (talk) 00:11, 31 December 2019 (UTC)

Mice

Based on studies of mice in 2005, an objection to calorie restriction in humans was a claim that the physiological mechanisms determining longevity are complex, and that the effect would be small to negligible. A subsequent study refuted the supposed tradeoff between calorie restriction and reproduction (in mice) from which this objection was derived. Another objection was the less stable metabolism of mice and linked opportunistic ecological niche (population variability) would mean mice are more susceptible to CR effects than humans. A previous study, projecting the larger benefits from earlier CR in mice to human lifespan, has been contradicted by evidence from CR in primates.

References

In reply to the comments above: The 2017 PMID 28977341 study says no such thing about rodent studies. Thank you for linking to it since it says the exact opposite, rodent studies are highly relevant.

Here's a quote: "However, only by examining the unique study design features highlighted in the primate studies and further illustrated in rodent models, we can accurately interpret the outcome and ultimately identify the relevant biological mechanisms." Or from the abstract: "These factors, that may be influencing the effects of a calorie restriction intervention, are highlighted in the rodent model to draw parallels and elucidate findings reported in a higher species, nonhuman primates."

This discussion is pretty insane and creates cognitive dissonance since anyone even glancing at the source PMID 28977341 sees the importance and relevance it places in mice studies.

I shall be working on a revised mice section, and anticipate the addition of a dog section.

Obviously there is great value in using sources 13-15 years old, the age of a source has no consequence on it's importance. For example, the wikipedia article on evolution is chock full of sources from the previous century. There is also one listed from 1872.

It's hard not to question the motives of the repeated cuts to the article of mice study information, and also hard not to see them as a violation of wikipedia policy. (unsigned; presumably IP user 67.243.247.88)

Anyone wanting a clear interpretation of CR effects on body weight can see the authors of PMID 28977341 feel the research has too many variables and is too preliminary to interpret anything relevant to humans. Wikipedia is not an undergraduate term paper where early-stage inconclusive lab research might be fair to discuss. MEDANIMAL states that lab research "makes for weak evidence, and allows for cherry picking of data. Studies cited or mentioned in Wikipedia should be put in context by using high-quality secondary sources rather than by using the primary sources." There are no relevant mice or dog studies to use in the encyclopedia article. Sources being 13-15 years old says 2 things clearly about the absence of research over the last 2 decades: the topic using animals is a near dead end, probably because 1) there are insufficient new directions from using lab animals to obtain grant financing, and 2) it must be a difficult topic to convince peers to accept grant applications or publications when research designs are so variable, leading to inconclusive outcomes. --Zefr (talk) 23:20, 31 December 2019 (UTC)

The editor above states "There are no relevant mice or dog studies to use in the encyclopedia article."

An editor claiming there are no relevant mice studies that can be used as sources for an encyclopedia article on calorie restriction has no business being allowed to participate in any editing at all. It's a pretty absurd statement, as is the denigration of sources 13-15 years old, per my example of evolution. This however seems to sum up the wierdness and bias of the editor. Denying the importance of lab mice studies on calorie restriction makes no sense and runs counter to the precepts of wikipedia and responsible editing.

Having followed guidelines for "Talk", obviously this has reached the next stage for Dispute Resolution. Please, somebody take the ball and run with it. I've provided all the necessary arguments and sources, and most importantly, so has the opposing editor with their "no relevant mice" position. What are we going to do tonight? Same thing we do every night. — Preceding unsigned comment added by 2604:2000:1742:83ED:2872:6060:9CE9:859F (talk) 16:35, 1 January 2020 (UTC)

Increase in the life span by CR

I remember I read an article by Dr. Ashok D B Vaidya which says that lifespan is prolonged if calorie restriction is done. I will find the reference soon and will add in the article soon after discussing here. -- Dr. Abhijeet Safai (talk) 09:27, 9 January 2020 (UTC)

It would need to be an excellent WP:MEDRS for such an extraordinary claim. Alexbrn (talk) 16:18, 9 January 2020 (UTC)

Review article on human aging and caloric restriction

Hi. It looks like calorie restriction delays aging: https://www.sciencedirect.com/science/article/pii/S2352396417302505 Would this source be suitable for inclusion in the wikipedia article? It is a review article. Thanks. ˜˜˜˜ — Preceding unsigned comment added by Lopkiol (talk • contribs) 22:43, 13 December 2021 (UTC)

It is not a meta-analysis or systematic review of studies, it's more of an opinion piece. Most of the trials on this topic are limited and only done for a few weeks or months there is no long-term data. For example this review [6] was recently published on caloric restriction on blood pressure and cardiovascular function but we do not know long-term effects about aging, as they have not been done yet. The data is currently limited and we need more long-term research. We need about 20 years more data on this topic if we are going to make claims about aging. Based on what I have seen because of the limited studies on this topic any long-term effects are not currently known. Psychologist Guy (talk) 02:42, 16 December 2021 (UTC)

Wiki Education Foundation-supported course assignment

This article was the subject of a Wiki Education Foundation-supported course assignment, between 12 August 2020 and 25 November 2020. Further details are available on the course page. Student editor(s): MasonBoxberger.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 16:35, 16 January 2022 (UTC)

Wiki Education Foundation-supported course assignment

This article was the subject of a Wiki Education Foundation-supported course assignment, between 25 October 2020 and 12 December 2020. Further details are available on the course page. Student editor(s): MeganWilliams33. Peer reviewers: AdamTski, Cpichany.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 18:33, 17 January 2022 (UTC)

Why have any information on Primates and Mice?

Either one is allowed to point out the differences between mice and primates CR or there is no reason to include any information on mice, or primates for that matter. Humans are only studying CR in primates and mice to advance the study of CR in humans. It would be stupid to only include the similarities and applicability of primate and mice studies, and omit the differences observed. The differences are important to know, and give insight into Calrorie Restriction, and must be included in any wikipedia article that purports to cover the subject.

I have earnestly endeavored to respond to any critism of recent edits. The only valid quibble might be some necessary repetition, since part of the information already appears in the Primates section: "Specifically, reduced food intake was beneficial in adult and older primates, but not in younger monkeys." This is not really a fault, articles nearly always repeat some information in various sections. Please note, I'm tired of trying to get these facts into the article. Please follow the wikipedia guidelines and respond to 'Talk' if there are questions regarding edits. — Preceding unsigned comment added by 67.243.247.88 (talk) 23:50, 28 December 2019 (UTC)

Non-history discussion

This revert was justified because the examples given are not from randomized controlled trials on calorie restriction, but rather are just isolated outdated observations. The 2016 review by Most et al. was updated in 2020 and is already included in the article. Under 'See also', there is an article on the Okinawa diet, but this is an outdated practice by some 70 years with little relevance to 21st century issues on calorie restriction.

The added section also contained grammatical and style errors - see WP:MOS. Zefr (talk) 18:08, 6 April 2023 (UTC)