Okay so to me CRON is just eating sensibly, not sure we need studies to prove that's a good idea. I'm healthy. I eat a vegan well rounded diet and cut calories when I am in loss mode. According to the good doc and many blood tests I get nearly all my nutrion needs w/o supplements. The only one I do take is a weekly dose of vit D2. So I guess I'm not sure 1 - Why we need such a fancy name as Calor,,, oh whatever, CRON? 2 - Why people are rejecting this so much?

Eat less, move more, eat foods with ingredients that come from the earth and not a lab. Ta da!

If I'm not mistaken, Calorie Restrition regimens are when people reach their goal weights, determine their maintenance calories, then CUT 30% of those calories, so they live on a severly restricted calorie intake.

They have to take special care to make sure that their nutrient requirements are met, but on 30% fewer than their maintenance calories. Generally, what happens is their BMR slows significantly to conserve energy when their bodies are at rest. And weight tends to gradually creep downwards until a balance between calories in and out is maintained. If you check out the websites of these restrictors, they are generally quite slender. Here's a link that details the specifics of this way of life:
http://www.calorierestriction.org/Getting_started
and the accompanying risks of this lifestyle:
http://www.calorierestriction.org/Risks

Calorie Restriction is controversial -- some studies on monkeys show they live LONGER in a controlled lab situation and this is the theory behind the diet -- severely restricting calories makes you "healthier" and you will live longer. Hence the daily posts touting this regime. Other studies show that you have to start this regimen very early in life to reap any benefits, the benefits are marginal in any event, and that severe calorie restriction makes one less able to fight off infection.

The issue isn't if you should eat to get maximum nutrition or if you should be aware of the source of your food and the quality of what you choose to eat. The issue is, if you get to a maintenance level of calories, which is for example 1900 calories, do you believe that restricting your intake to 1300 calories a day has any benefit for you. For every "pro" study, there are two or three "con" studies, so I fear that the whole picture isn't being accurately portrayed...

IMHO, I think I will FEEL like I'm living a longer life if I severely restrict. But in terms of health and nutrition, I can manage just fine on a usual maintenance level of calories and a healthy balanced diet.

Kira

Nature and genetics may indeed play a much stronger role in longevity than diet. The ranks of 100-year olds are not exactly populated by marathon runners. Most have never exercised and some have smoked for 90 years. Many without a doubt, have a genetic quirk.

For the rest of us mortals, we all should do what we can to increase our chances. For yours truly, I've chosen the calorie restriction with optimal nutrition lifestyle.

Bo

Thanks for those links, Kira (kiramira) - they seemed balanced and rational. I've followed the CRON discussions since I do believe that the science with rats is real, and of course have no idea how well that translates to humans.

But I just gotta admire one line from the Risks page:
Thought that was an appropriate quote for all forms of healthy eating.

Thanks Kira. I was at work earlier and just basing what I thought it was off of the posts in here and then seeing Bo's calories for the day. To me (in a hurried read anyway!) those seemed not that drastic. I understand now.

My biggest issue is that what happens to one species will not necessarily happen to others. This is why animal testing is well, bogus. It's a starting point perhaps but rarely to the exact results happen to humans. I'll stop before I start ranting on this . Human studies would be far more accurate but I do agree that it's hard to isolate the exact cause for longer lives. Of course, there are fat inactive people that live to be 90. Does that mean I'm going to eat french fries everyday and not exercise? No.

Other then that, meh do what you feel. I personally think it would be difficult to stick to for me and wouldn't really consider it but power to you if you think it'll work and you can hang with it.

Amen brother, amen. The looks/questions/snickers I've gotten for not eating at social gatherings because the food wasn't vegan and/or healthy.....

Calorie Restriction should be implemented gradually. Reducing caloric intake quickly does not allow the metabolism to adjust to the caloric deficit. Sudden calorie restriction can create major health problems. In particular, persons who have a Body Mass Index (BMI) below 22 should be very cautious. Calories should be reduced by less than 5% (less than 100 calories) and maintained for at least four weeks before any additional reductions are made. You should not restrict calories further if your BMI is below 19. On the contrary, you may need to increase your caloric intake to maintain your BMI within the normal range (from 18.5 to 24.9). Do not exceed 16% CR since greater restriction can result in loss of structural tissue, including bones and muscles.

A more recent study based on 99,253 male physicians found that those with a BMI less than 20 had a 12% lower relative risk of death when compared to men with BMI from 22.5 to 24.9, and higher BMIs were associated with an increased relative risk of mortality. Another large prospective study of 894,576 participants found the optimum BMI for longevity to be from 22.5 to 25. Evaluation of studies published in peer-reviewed journals during the last 40 years has led Dr. Luigi Fontana to conclude that CR may be harmful for lean persons who have minimal amounts of body fat. The rate of suicide has been found to be greater for men with BMIs below 21 than for men with higher BMIs, and analyses of mental health-related quality of life also showed a positive relationship with increasing BMI.

You can check your BMI at: nutrition.about.com/library/bl_bmi_calculator.htm

Hope this helps.

Bo

Regardless of how many studies you refer to, I can find an equal number that counter them.
For example:

From the CMAJ re: Clinical guidelines:

People aged 65 years or older who are overweight may not be at increased risk of health problems, whereas those who have a BMI in the low end of the normal range (between 18.5 kg/m2 and the low 20s) may be at increased risk. Thus, the normal-weight or low-risk BMI range may be higher and wider (e.g., 22–29 kg/m2) for elderly people than the range for younger adults (18.5– 24.9 kg/m2). Weight loss in elderly people, especially loss of fat-free mass, regardless of the baseline BMI, is associated with an increased risk of death.http://www.cmaj.ca/cgi/content/full/172/8/995

or this:
http://junkfoodscience.blogspot.com/...or-longer.html
which noted:

If caloric restriction can delay aging, then there should have been significantly fewer deaths in the dieting group of monkeys than in the normally fed comparison group. But this is not the case. Though a smaller number of dieting monkeys have died, the difference is not statistically significant, the Wisconsin team reports.

No statistical difference. It was a null study that to date has failed to support the calorie restriction hypothesis.

I mean, we can play the "I quote, you quote" game until the cows come home (preferably as hamburgers). The bottom line is, IMHO, Calorie Restriction is an extreme form of lifestyle, hence the low numbers of people who adhere to it (less than 1000 world wide!).

It is a lifestyle whose risks IMHO outweigh the POTENTIAL UNPROVEN benefits.

And the significant risks are detailed in my post above, as found on the Calorie Restriction home site! Your home organization know this is dangerous! Hence the long term decrease in calories, so you don't die! The great care not to become malnourished! The great care taken to distinguish your views from those of an anorexic lifestyle!

I appreciate that you are on your own path, and wish you well. But all the "studies" you present just aren't convincing enough for me to choose this type of lifestyle. And no amount of propaganda will convince me otherwise.

-peace, OUT...

Kira

There's something a little bit disingenuous about a man lecturing women on severely restricting calories. Most of us can only DREAM of eating as much as you do!

Oh good grief, that is not what is happening here. CRON is a concept the OP did not invent. Agree with it or don't agree with it, but this is nothing to do with what you just said.

I saw the Oprah episode recently about calorie restricting extending life spans. As I recall no one they interviewed was restricting their calories to an unhealthy level. I believe the woman they interviewed was in the 1600 range and her husband in the 1800 range.

I don't think anyone was starving, they were just choosing foods that were very nutrient dense and lots of volume for the calories. The guy eating the apple peels also ate lots of berries with them. Then for lunch he had a huge salad that weighted 3 pounds. Then dinner looked to be fish or chicken with healthy sides like veggies.

At the end of the day we all need to practice some kind of calorie restriction to loose weight, it's just finding the right balance that works for you. Now rather restricting calories will help me life a healthier, longer life I don't think we can really know for certain anytime soon.

I wonder if you restricted calories, but ate junk food would it still be possible to live longer? It seems to me the real key is that you are eating low calorie foods, which of course happen to be fruits and veggies. Is it really the restriction of the calories, or the increased consumption of fruits and veggies that helps you inprove our health/life span?

Personally I could never give up the occasional yummy foods like pizza and cake, even if that means I die a few years early.

Actually, I agree with everything that you’ve noted above. There are many who practice extreme versions of the lifestyle and for them the risks cannot and should not be ignored.

Regarding calorie restriction, I’ve adopted a much more moderate version that simply limits calories to maintain a weight at the mid point of the healthy BMI range. Btw, it was not easy and took over a year to get there.

I’m not for a moment trying to convince anyone to adopt the lifestyle as promoted on the net. Just sharing what little I know with those who might be interested. I’m no cron salesman and only suggest if we eat healthily, exercise sensibly and sleep well, we will more than likely live a longer healthy life.

Achieving outstanding health is not complicated. The human body already knows how to be healthy. All we have to do is maintain a healthy weight and give our bodies outstanding nutrition so that it has the building materials it needs to heal disease and rebuild itself from the inside out.

Wishing you well, take good care of yourself.

Goodbye.

Bo

Well stated! I agree with all this, Bo (BoBoGuy), which seems a bit distanced from my reading of the CRON philosophy. Seems to me that you're on a path that would be admired by any of the folks around here attempting to maintain over the long run.

Hope it continues to work for you.