106 replies to this topic

[Shannon Vyff]

I try to stay at 1200, but invariably end up at 1400--I'll rarely go higher, only say after extreme physical effort (and then I up my ratio of protein).


Might want to put in the title, the if you are on (or practice) CR then--how many calories do you take? (to make it more clear, many will vote then read the thread)

[EmbraceUnity]

Might want to put in the title, the if you are on (or practice) CR then--how many calories do you take? (to make it more clear, many will vote then read the thread)

Yes, I probably should've done that. Can't edit it anymore though.

I probably eat 2000-3000 calories on normal days, but I fast once or twice per week. I also try to eat less meals per day, though lately that hasn't been the case. Intermittent Fasting isn't CR, I know... but it is a similar principle.

Edited by progressive, 01 March 2008 - 09:02 AM.

[Johan]

I eat 1600 calories per day on zoned CR (30% protein, 40% carbs, and 30% fat). I've been doing "real" CR for about two months now, and before that I ate a healthy diet that was low in calories, so it was kind of CR but not really. 1600 kcal/day keeps my BMI at about 17.5 (5'10" and 120 lbs), and I'm happy with that. The Swedish Institute of Health recommends an intake of 2500-2800 kcal/day for adult men, so that's roughly 40% restriction. I eat four meals per day, of about 400 kcal each.

Edited by Johan, 02 March 2008 - 10:25 AM.

[Matt]

1700k/cal at the moment. Was at 1550k/cal earlier on but had to raise calories. Both levels of CR are easy to do.

Edited by Matt, 01 March 2008 - 10:28 PM.

[NickC11]

Not on regulated CR, but don't eat much. I find I usually end up drinking meal-replacement drinks and if I must eat, sticking to high protein stuff and avoiding starchy foods (e.g. bread). On an average day I'd estimate around 1800 calories.

[Johan]

I recently increased my calorie intake to 1700 kcal/day because my BMI was close to 17.0 - I'd like it more along the lines of 17.5.

[forever freedom]

I don't count, but it's probably more than 2000.

[vyntager]

Strange thing to see a lot of people as low as 1000-1200 Calories per day, with maybe the implication that anything near the 2000 Cal range isn't CR anymore.

What I'm thinking about is, just how tall are you ?

CR works by cutting the amount of calories you'd eat ad libitum, to anywhere between 35 to, say, 80-90%, with more benefits the lower you goes, until the 30% range. Below that the restriction seems to be too high, and the benefits of CR disappear, probably because you can't sustain your own basal metabolism. Basal metabolism is linked to one's size.

So someone with a bigger stature will certainly not be able to go as low as those with a lighter frame / shorter.

Practically, the part of the definition that refers to "ad libitum" bothers me. How do I know my ad libitum regime isn't already lower than that of another individual my size; or higher for that matter ?

I'm 187 cm (6 feet 2 inches) high, if I were weighting 61 kg (134 pounds), I'd have a BMI of about 17.5, which seems about right for CR. At this weight and size, my estimated basal metabolism would be 1670 Cal.
Even if I were totally sedentary, my resting metabolism would be about 2000 Cal, more with even a little physical activity, and physical activity such as sports is a near certainty for me.

If I were to eat anything less than that, I'd necessarily loose more weight, resulting in a lower BMI, and from what I've seen on this forum, people with a BMI lower than about 17 usually choose to eat more because they didn't feel comfortable for whatever reason (social, physical, etc.). Even if I were to go as low as 50 kg (BMI of *14.3*), I'd still need at the very least 1850 Cal, probably more due to physical activity. Just a point, thus, and I'm still curious about your sizes compared to the amount of calories you get per day of course.

Edited by vyntager, 06 April 2008 - 11:45 PM.

[Matt]

vyntager I know what you mean about judging your own calorie intake and reducing calories from it. I have probably been doing some form of CR for most of my life, almost certainly my teenage years. About 40% of my life so far I've been drifting between underweight and very low normal. My normal calorie intake was pretty low even before CR, as most of my teenage years I was just eating foods such as whole grain cereals with fruit... we couldn't afford all those luxuries. Not the best diet... but it was CR compared to the large majority of people. I'm 23 1/2 years old now, I can get away with being about 16 years old, I just wonder whether it has anything to do with me looking quite young for my age. I'm also about 2 1/2 inches less than the average male height in the UK and have small body frame.

Edited by Matt, 07 April 2008 - 09:37 AM.

[Zans Mihejevs]

Below that the restriction seems to be too high, and the benefits of CR disappear, probably because you can't sustain your own basal metabolism. Basal metabolism is linked to one's size.

I hear that a lot, but are there any actual studies suggesting that this is true? Mice benefited from restrictions as high as 65%, so I'm not sure where you're coming up with your data.

[VictorBjoerk]

Strange thing to see a lot of people as low as 1000-1200 Calories per day, with maybe the implication that anything near the 2000 Cal range isn't CR anymore.

What I'm thinking about is, just how tall are you ?

CR works by cutting the amount of calories you'd eat ad libitum, to anywhere between 35 to, say, 80-90%, with more benefits the lower you goes, until the 30% range. Below that the restriction seems to be too high, and the benefits of CR disappear, probably because you can't sustain your own basal metabolism. Basal metabolism is linked to one's size.

So someone with a bigger stature will certainly not be able to go as low as those with a lighter frame / shorter.

Practically, the part of the definition that refers to "ad libitum" bothers me. How do I know my ad libitum regime isn't already lower than that of another individual my size; or higher for that matter ?

I'm 187 cm (6 feet 2 inches) high, if I were weighting 61 kg (134 pounds), I'd have a BMI of about 17.5, which seems about right for CR. At this weight and size, my estimated basal metabolism would be 1670 Cal.
Even if I were totally sedentary, my resting metabolism would be about 2000 Cal, more with even a little physical activity, and physical activity such as sports is a near certainty for me.

If I were to eat anything less than that, I'd necessarily loose more weight, resulting in a lower BMI, and from what I've seen on this forum, people with a BMI lower than about 17 usually choose to eat more because they didn't feel comfortable for whatever reason (social, physical, etc.). Even if I were to go as low as 50 kg (BMI of *14.3*), I'd still need at the very least 1850 Cal, probably more due to physical activity. Just a point, thus, and I'm still curious about your sizes compared to the amount of calories you get per day of course.

http://www.dallasnew...orie.5373e.html

As you can see a 6'2 man can easily live on as little as 1100 calories a day.

I have a medical book that says humans can easily live on a daily intake of as little as 20 kcal per kilogram.
I am surprised that so many here doing cr eat so much.

BTW what is the actual average calorie intake for the average slightly overweight american.Is it in the range of 3500 or something?

[pseudo-princess]

About 1300-1400 for me; I've been doing this for the past 4-5 years (even before I knew what CR really was.) I'm 5'4", female, with a pretty small frame, and a BMI of 23. The very average BMI suggests that I probably should reduce my calorie intake even further I suppose.
I find it interesting that someone said that he looks much more childlike, possibly due to CR. I didn't grow since I started it, though that was around age 15-16 and apparently many girls don't grow very much after that age. I've also been mistaken for 15, though others think I'm 25 (I'm 20) so I think it has more to do with my hairstyle and clothes than anything else haha.

[VictorBjoerk]

About 1300-1400 for me; I've been doing this for the past 4-5 years (even before I knew what CR really was.) I'm 5'4", female, with a pretty small frame, and a BMI of 23. The very average BMI suggests that I probably should reduce my calorie intake even further I suppose.
I find it interesting that someone said that he looks much more childlike, possibly due to CR. I didn't grow since I started it, though that was around age 15-16 and apparently many girls don't grow very much after that age. I've also been mistaken for 15, though others think I'm 25 (I'm 20) so I think it has more to do with my hairstyle and clothes than anything else haha.

Are you really doing cr with a bmi of 23?You maybe only eat healthy and estimate calories?

Edited by Shonghow, 09 May 2008 - 12:34 PM.

[Matt]

Real anti aging CR is about reducing your calories from a NORMAL BMI. Which most of the time means you end up being very low normal or underweight. I think if you want to be cautious then something like BMI of 20 is probably a nice goal.

[VictorBjoerk]

Is slow metabolism something good when doing CR?The scientists seem to differ on the question...Wouldn't the ancient monks have experienced the CR effect when fasting long periods and then starting eating normally.They often ended up quite chubby however because their body turned more efficient in using energy.But I suspect they would have had experienced at least a weak effect because their calorie intake measured during a year may have been lower than normal although their weight was normal to slightly overweight.

[vyntager]

Note : Cal (with capital C) is kcal, they mean the same thing.

http://www.dallasnew...orie.5373e.html

As you can see a 6'2 man can easily live on as little as 1100 calories a day.

If you use the Harris-Benedict equation, or the Mifflin-St. Jeor one, and put 1100 Calories a day as the intake, then you have a male human of 187 cm weighting respectively 19 kg (Harris-Benedict) and 4.5 kg (Mifflin-St. Jeor); that's with no activity whatsoever, btw, just basal metabolism rate.

Obviously it musn't fit the data very well in those ranges, yet I don't think that even with double that weight you'd be healthy (38 kg = BMI of 10.8 for a 187 cm man). Even considering that this is the weight of the more metabolically active, and essential tissues, and that bone and other such stuff has negligible needs, and that your metabolism gets more efficient as you are under CR, you can't. That's just too low.

As a guide to minimum calorie intake, the American College of Sports Medicine (ACSM) recommends that calorie levels never drop below 1200 calories (sic) per day for women or 1800 calories (sic) per day for men. Even these calorie levels are quite low.

http://www.acsm.org/...ontentFileID=31

And that's for weight loss dieting. Maybe that is what you meant. If you can tap into your body fat reserves, then sure you can go as low as 1100 Calories per day. It's just that it is not sustainable in the long term. You'll loose weight (that is, fat and muscle mainly) until the mass of metabolically active tissue in your body consumes about 1100 Calories per day, at which point you'll be in equilibrium, or else you may also simply die before reaching that point due to inadequate supply starving your essential organs.

I hear that a lot, but are there any actual studies suggesting that this is true? Mice benefited from restrictions as high as 65%, so I'm not sure where you're coming up with your data.

http://physrev.physi...stract/77/3/731
http://cancerres.aac...Part_2/2336.pdf
http://www.pubmedcen...i?artid=1221750

Those three links are all we should need. From that you can calculate that some of the most essential functions of your body (ion pumps, protein synthesis ... the works) is 3 g of protein per kg of body per day for a male human adult.

You need about 20 kilojoules per gram of protein formed (in pigs, admittedly, but their biochemistry isn't that different from ours, especially for something as conserved as protein biosynthesis)(but if you prefer, it was estimated to be 180 Cal for a 70 kg human, peptide bond only, and about 5 times that much for the whole biosynthesis, 900 Cal) and that quantity is estimated to be at most 30% of the resting metabolic rate (that one is in human beings).

So, say you have that skinny guy whose weight is an absurdly low 33 kg. That's a need of about 100 g of protein per day, which means 2000 Kilojoules expended on synthesis, amounting to 477.7 Calories (or if you want to use the much sloppier results in humans, you'd still get about (900/70) * 33 = 424 Cal).

And that, my friend, is but 30 % of the total RMR at most. In which case the resting metabolism rate of that guy is about 1592 Calories per day (1413 Calories with the 424 Cal per day of protein synthesis), which is a tad higher than the BMR results for the Harris-Benedict and Mifflin-St. Jeor, but that's his resting metabolism rate, which is supposed to be higher than his basal metabolic rate anyway.

For a 33 kg man

With a BMI of 9.43 if he were 1.87 m high

Who don't do anything aside from basic metabolic lving, no physical activity, not even moving, nothing more

I have a medical book that says humans can easily live on a daily intake of as little as 20 kcal per kilogram.

References ? Furthermore, check, under which conditions, maybe they are non standard; my guess is that you can do that as long as you have reserves, like fat, muscle tissue, etc., and even then, not for too long. I obtain about 42 Cal at the very least. You can make a case for the metabolism being more efficient, but not for a twofold difference. And under no conditions can I imagine that it would be easy to live with 20 Cal per kilogram.

[VictorBjoerk]

Why should there be such a underestimate in the article in Dallas News.The food shown in the picture seems to be closer to 1100 than 2000 Kcal.

http://www.aleph.se/.../cr-how-to.html

Read this written about calorie restriction by Steve Chambers

He states "it´s quite possible to get by indefinitely with less than 20 calories for every kg of body weight"

I'm not saying it's true however.....

[vyntager]

Why should there be such a underestimate in the article in Dallas News.The food shown in the picture seems to be closer to 1100 than 2000 Kcal.

It's a newspaper, so it's not as accurate as a scientifical publication, there may be an error; the picture too need not be scientifically accurate, its purpose is almost certainly only to emphasize what CR really means, so that readers get that you may have to eat mostly vegetables, and not a lot of food at all.

Besides, that guy's also older (56), and basal metabolism diminishes as you age (though not to such an extent as to make a 1100 Cal diet sustainable yet). His weight, he says, is now (circa 2004) under 130 pounds (starting from 165). But has he stopped thinning yet ? I've been trying to compute how much he's eating from what's shown and said in the article, but it doesn't give relevant results from lack of data. It seems, however, that he has to eat more than that, since as far as I can see it adds up to even less than 1100 Cal.

Also :

And when dining out with friends, he adapts. "They probably won't notice, but I'll eat less than they," he says. "I'm not going to stand out in a crowd. I'm not going to carry lettuce to a party."

Eating less, but is he on CR then ? How often does that happen ?

http://www.aleph.se/.../cr-how-to.html

Read this written about calorie restriction by Steve Chambers

He states "it´s quite possible to get by indefinitely with less than 20 calories for every kg of body weight"

I'm not saying it's true however.....

Everything I know tells me it isn't possible. I may have to dig deeper, since I'll need those results if I am to do CR. But meanwhile, on top of my head;

did those persons check their science before pulling those numbers, to see if it was even possible ?

if they have been under such a low level of CR for a significant amount of time, have they been consistently losing weight, has it never stabilized ?

how are they gauging their calorie intake ? Guesswork, or precisely, with scales and a program such as dwidp or cron-o-meter ? (btw, on the latter, if I put data for a man my size and the desired weight I'd wish for, say, 60 kg, sedentary, I'm told I need 2361 Calories per day, minimum.)

 20080513a.JPG   80.37KB   185 downloads

BTW what is the actual average calorie intake for the average slightly overweight american.Is it in the range of 3500 or something?

http://www.fao.org/s...-of-America.pdf

Actually, and for the years 2001-2003, the average american ate about 3770 Calories per day, and the trend seems to be for that quantity to be raising, at least it has been since 1973.
Then again the average american is overweight indeed.

Mice benefited from restrictions as high as 65%

65 % CR, right on. But 65% of what ? Just how well, how richly were those ad lib mouses fed anyway ? If it were for humans, you might decide to take 65% out of the 3770 Cal of the average american, and you'd end up with a 1319 Calories per day diet, for a 175.8 cm high average male american, that being the lowest he could go to see positive results from his diet.

[VictorBjoerk]

Yes 20 kcal per kilogram seems too low to sustain your life on.The same man was featured in scientific american many years ago,then weighing 110 but eating 1500 calories a day...It may be a newspaper error..

[pseudo-princess]

I estimate on a few things (like veggies) but still rarely go over 1400 or 1500. I have mild hypothyroidism though; when I was eating 2000 calories I was overweight.

About 1300-1400 for me; I've been doing this for the past 4-5 years (even before I knew what CR really was.) I'm 5'4", female, with a pretty small frame, and a BMI of 23. The very average BMI suggests that I probably should reduce my calorie intake even further I suppose.
I find it interesting that someone said that he looks much more childlike, possibly due to CR. I didn't grow since I started it, though that was around age 15-16 and apparently many girls don't grow very much after that age. I've also been mistaken for 15, though others think I'm 25 (I'm 20) so I think it has more to do with my hairstyle and clothes than anything else haha.

Are you really doing cr with a bmi of 23?You maybe only eat healthy and estimate calories?

[Mewtwo]

Here is what I had today:

Carrots, raw 2
Tomatoes, red, ripe 1
Wheat bran, crude 1 cup
Apples, raw, with skin 1
Bananas, raw 0.5
Cucumber, with peel, raw 1
Spinach, raw 0.5 package (10 oz)
Yogurt, Dannon Light n' Fit 1 Cup
Blueberries, raw 1 cup
Peppers, sweet, green, raw 1
Milk, nonfat, (fat free or skim) 1 cup
Grapes, red or green raw 10 grapes
Nuts, almonds ~10 almond
Orange juice, raw 1 cup
Cookies, fig bars 1 cookie

===========================================
Nutrition Summary for July 3, 2008
Report generated by CRON-o-Meter v0.9.3
===========================================

General (73%)
===========================================
Energy | 1000.9 kcal 100% (under my settings 1000 = 100%)
Protein | 42.2 g 75%
Carbs | 215.9 g 166%
Fiber | 50.8 g 169%
Fat | 13.5 g 21%
Water | 1640.7 g 44%

Vitamins (91%)
===========================================
Vitamin A | 41646.7 IU 1388%
Folate | 534.3 µg 134%
B1 (Thiamine) | 1.2 mg 103%
B2 (Riboflavin) | 2.1 mg 163%
B3 (Niacin) | 15.5 mg 97%
B5 (Pantothenic Acid)| 4.7 mg 95%
B6 (Pyridoxine) | 2.4 mg 142%
B12 (Cyanocobalamin) | 1.9 µg 78%
Vitamin C | 337.7 mg 375%
Vitamin D | 198.0 IU 50%
Vitamin E | 10.9 mg 73%
Vitamin K | 819.6 µg 683%

Minerals (90%)
===========================================
Calcium | 971.6 mg 81%
Copper | 1.7 mg 184%
Iron | 14.6 mg 183%
Magnesium | 692.7 mg 165%
Manganese | 9.9 mg 429%
Phosphorus | 1472.8 mg 210%
Potassium | 4997.0 mg 106%
Selenium | 54.7 µg 100%
Sodium | 544.7 mg 42%
Zinc | 8.4 mg 76%

Lipids (18%)
===========================================
Saturated | 2.0 g 10%
Omega-3 | 0.5 g 32%
Omega-6 | 3.9 g 28%
Cholesterol | 7.9 mg 3%




I do not see why people would be hungry on CR. It can be a lot of food!

[Forever21]

not officially on CR yet but today i think i had 600-700.

[JLL]

I've been pondering this ever since I tried CR for a week or so (I documented it on my blog if you're interested: http://inhumanexperi...... restriction).

I've always been quite skinny and have lately been wondering whether I've been practicing a mild CR since childhood. It's of course difficult to estimate, but thinking back it seems reasonable that I ate less than most people I was around, including those who were shorter than me.

What I don't really get is how one defines the baseline energy intake. Depending on the equation, a person of my height and weight would seem to need between 2,000 and 2,700 kcal per day to maintain current weight. But if we assume I have already been doing a mild CR for several years, would eating 2,000 per day (which is probably close to my ad libid intake these days) constitute as CR?

I mean, how do you define what the "normal" weight for each person is? I know a lot of people who are shorter than me and weigh much more; yet for them 2,000 would definitely be less than ad libid and hence, I guess, CR.

I assume some of my being skinny could be attributed to metabolism (sometimes I feel like I can eat a lot more than some people and still not gain weight), but when I was on a noodles & beer diet for a few years, I did gain 10 kilos, so clearly it is possible for me to be chubbier.

I'm 182 cm and weigh 61 kg, which gives a BMI of 18.4. I think that's pretty close to what it's always been. The only thing that's changed since my younger days is that I've replaced some fat with muscle.

Edited by JLL, 01 August 2008 - 01:06 PM.

[VictorBjoerk]

Well I don't understand that someone 6'2 tall and 130 pounds can live on 1100 calories a day when for example the famous Cr practitioner Michael Rae lives on around 1900...

[vyntager]

Well I don't understand that someone 6'2 tall and 130 pounds can live on 1100 calories a day when for example the famous Cr practitioner Michael Rae lives on around 1900...

Maybe some people feel like embellishing their own story; CR isn't about who's got the lowest Cal per day, it's not a race and there's no price when they'll get to the finish line. Or maybe it's just wishful thinking combined with guesswork / inaccurate daily calorie intake tracking.

Anyway;

I mean, how do you define what the "normal" weight for each person is? I know a lot of people who are shorter than me and weigh much more; yet for them 2,000 would definitely be less than ad libid and hence, I guess, CR.

Normally that normal weight is assumed to be the whatever your weight was around when you were in your early twenties, under normal conditions; that is, your set point, while you were eating just as much as you'd need to feel content.

As you said, some people are slimmer than others even if eating as much, then there are some who naturally eat less, etc.

That's just my opinion, but someone who'd want to do CR and whose set point didn't seem like a good way of assessing her normal weight, should maybe try to keep track of her BMI and her body fat ratio. A BMI under 16-17 mightn't be healthy, under 14 definitely would be dangerous, as would a body fat percentage below 2-5 % (for men) and 12 - 15 % (for women). Get below that for either of those, it's time to put on some weight or fat.

As to how much one should eat to stabilize around those figures, well we have such things as the harris benedict equation, but it's not bound to be accurate for everyone, it's just accurate as an averaged case.

[Michael]

After finding out that some people on CR go as high as 1900 kcal per day, I'd like to look have a look at some statistics.

Not just 'some': nearly all real CR practitioners (who actually weigh and measure their food) report numbers up there, with the exception of a few tiny, largely sedentary women:

The CR subjects designed their diets to consume a balance of foods that supply more than 100% of the Recommended Daily Intake (RDI) for all of the essential nutrients, while minimizing energy content (1,112-1,958 kcal/day). They eat a wide variety of vegetables, fruits, nuts, dairy products, egg whites, wheat and soy proteins, and meat (≈26% of calories from protein, ≈28% from fat, and ≈46% from complex carbohydrates). All of CR group strictly avoid processed foods containing trans fatty acids and high glycemic foods (e.g., refined carbohydrates, desserts, snacks, and soft drinks). (1)

But that range is very skewed by a single female subject with the 1100 Cal diet: she's one a' them tiny, older, almost inactive women -- AND that number is a bit low because it doesn't represent her most typical long-term pattern, which includes weekly unmeasured restaurant meals. When you look at the average and standard deviation, even including her as an outlier, you see:

The CR subjects ate a nutritionally balanced diet (4) (at least 100% of the Recommended daily intake for each nutrient) providing approximately 1,671 ± 294 kcal/day (p = 0.0001 vs. WD group), approximately 23% protein, (p = 0.0001 vs. WD group), approximately 49% complex carbohydrates, approximately 28% fat, approximately 6% saturated fat. (2)

These numbers seem low because most people have no damned idea how much food they're eating, and believe they're eating much less: studies on this have found most people underreport by about 30%, with overweight people being more prone to misremember, misunderstand, or misrepresent their intake (4-7).

If you're on CR, please answer the poll and explain why you've chosen this calorie range. Also note how long you've been doing CR so far.

1860; ten years. My Calorie intake has been as high as 2000 and as low as 1800. I don't let myself drop below 115 lbs, so I keep my Calories as low as possible while maintaingn my light cardio and resistance exercise without overshooting this; I have no really good scientific justification for this particular cutoff -- I'm just too damned skinny already .

Personally, I only started a few days ago on 1400 (30% of RDA seemed like a good starting point) and am planning to adjust it accordingly depending on how I feel.

If your CR diet is good, you can feel full, initially, on very low Calories -- especially if you're at all overweight. If you're losing more than a pound and a half of so of weight a week and are doing resistance training (and if you're NOT doing resistance training, get your ass in gear), you should slow down before you either hurt yourself (eg, (3)), nix your CR bennies, or drive yourself nuts with hunger when your fat loss starts to run out and your body starts screaming for food, leaving you to go off the program (as has, anecdotally, happened to many, many people who've started CR too fast).

-Michael

1. Fontana L, Meyer TE, Klein S, Holloszy JO.
Long-term calorie restriction is highly effective in reducing the risk for atherosclerosis in humans.
Proc Natl Acad Sci U S A. 2004 Apr 27;101(17):6659-63. Epub 2004 Apr 19.
PMID: 15096581 [PubMed - indexed for MEDLINE]

2. Meyer TE, Kovács SJ, Ehsani AA, Klein S, Holloszy JO, Fontana L.
Long-term caloric restriction ameliorates the decline in diastolic function in humans.
J Am Coll Cardiol. 2006 Jan 17;47(2):398-402.
PMID: 16412867 [PubMed - indexed for MEDLINE]

3. Arguin H, Bouchard DR, Labonté M, Carpentier A, Ardilouze JL, Dionne IJ, Brochu M.
Correlation between the rate of weight loss and changes in body composition in obese postmenopausal women after 5 weeks: a pilot study.
Appl Physiol Nutr Metab. 2008 Apr;33(2):347-55.
PMID: 18347690

4. : Schatzkin A, Kipnis V, Carroll RJ, Midthune D, Subar AF, Bingham S, Schoeller DA, Troiano RP, Freedman LS.
Free Full Text
A comparison of a food frequency questionnaire with a 24-hour recall for use in an epidemiological cohort study: results from the biomarker-based Observing Protein and Energy Nutrition (OPEN) study.
Int J Epidemiol. 2003 Dec;32(6):1054-62.
PMID: 14681273 [PubMed - indexed for MEDLINE]

5. Gnardellis C, Boulou C, Trichopoulou A.
Abstract
Magnitude, determinants and impact of under-reporting of energy intake in a cohort study in Greece.
Public Health Nutr. 1998 Jun;1(2):131-7.
PMID: 10933410 [PubMed - indexed for MEDLINE]

6. Lichtman SW, Pisarska K, Berman ER, Pestone M, Dowling H, Offenbacher E, Weisel H, Heshka S, Matthews DE, Heymsfield SB.
Abstract
Discrepancy between self-reported and actual caloric intake and exercise in obese subjects.
N Engl J Med. 1992 Dec 31;327(27):1893-8.
PMID: 1454084 [PubMed - indexed for MEDLINE]

7. Mahabir S, Baer DJ, Giffen C, Subar A, Campbell W, Hartman TJ, Clevidence B,
Albanes D, Taylor PR.
Calorie intake misreporting by diet record and food frequency questionnaire
compared to doubly labeled water among postmenopausal women.
Eur J Clin Nutr. 2005 Dec 14; [Epub ahead of print]
PMID: 16391574
-Michael

[JLL]

Normally that normal weight is assumed to be the whatever your weight was around when you were in your early twenties, under normal conditions; that is, your set point, while you were eating just as much as you'd need to feel content.

Do serious CR practitioners feel content or hungry? Obviously, if they just restricted calorie intake without paying attention to what it is they eat, they'd be hungry all the time, but from what I've seen, most of them choose foods with high nutritional values and low energy so they'd feel content.

If I use the "daily calorie requirements" equations as a set point I'm already doing CR; however, I'm not sure whether the benefits of CR work this way. On the other hand, if I used my current intake (about 2,000 kcal) as the set point, I'd have to cut down to at least 1,750 kcal, which would mean my BMI would soon be less than 17, and still it'd only be a 12.5% CR, which is not a lot.

Thus, it seems to me that if you really define the set point as the amount of calories you normally eat, then people who eat a lot and are fat are the only ones who can properly do CR and get any longevity benefits from it. If you're normally eating 4,000 kcal per day, it's a lot easier to do 50% CR than if you're eating 2,000 kcal per day.

If anyone has more info on the subject, I'm very interested. Thanks.