Monday, November 20, 2006

Calorie Restriction

(from The New York Times: two rhesus monkeys about the same age, one fed a CR diet,left, the other fed a normal diet)

A number of people have asked about my thoughts on calorie restriction, the movement that follows the notion that the less you eat, the more years you’ll live. The idea is that giving up those hearty meals, those decadent treats, those full-plate or even half-plate servings, you may up your chances at living a longer, healthier life. And, so on the almost-eve of America’s national overeating challenge, I offer some thoughts on calorie restriction. Please keep in mind that these observations/interpretations are from a psychological, not nutritional or biomedical perspective, and that the fact that a clipping on calorie restriction (CR) that I had saved for this post just caught fire on a candle I’m burning at my desk does in no way reflect on my thoughts about CR.

CR involves consuming about 30% fewer calories per day than is generally recommended for one’s height, weight, and body type. The key, though, is that amounts of vitamins, minerals, and other essential nutrients are kept constant (or even enhanced), resulting in a kitchen laboratory of sorts, where scales, measures, and computer monitoring ensure adequate levels of nutrients on a largely barren plate. From what I understand about nutrition, this may not be the easiest task.

Support for CR dates back to 1935, when Dr. Clive McKay, a researcher at Cornell University found that rats fed a CR diet lived approximately 40% longer than their normally-fed counterparts. Similar results have been found in primate populations, where like in mice, scientists are seeing reduced incidences of diabetes, heart disease, cancer, and other ailments with the introduction of CR.

Does CR work in humans? They’re not so sure. The truth is, the scientific community isn’t exactly sure how CR works at all. Still, several hundred thousand people have swapped their cookbooks for cooking scales, their large serving plates for the ceramic equivalent of “just a little bit.” A New York magazine article focuses on Michael, a bona fine calorie restrictor, who at 6’ feet tall and 115 pounds consumes 1,913 calories per day. Exactly 1,913. His dinner, his girlfriend (also a CR devotee) explains, is “‘always 639 calories.’” Other CR followers profiled in the article skip meals or consume a single meal per day.

A New York Times article reports that scientists at Washington University who have studied a group of calorie restrictors have found that “the dieters had better-functioning hearts and fewer signs of inflammation, which is a precursor to clogged arteries, than similar subjects on regular diets.” According to the Times, research published in JAMA has also suggested that those on CR diets have lower body temperatures, lower insulin levels, and fewer indices of chromosomal damage linked to the aging process.

On other hand, the Times reports that:
A mathematical model published last year by researchers at University of California, Los Angeles, and University of California, Irvine, predicted that the maximum life span gain from calorie restriction for humans would be just 7 percent. A more likely figure, the authors said, was 2 percent.
Is it really worth it, to give up (for a lifetime) the decadence, the luxury, the indulgence of food for an extra couple of years? One of the paper’s authors, Dr. Jay Phelan at UCLA says: “‘Calorie restriction is doomed to fail, and will make people miserable in the process of attempting it.’”

As with many enterprises (especially surrounding food and weight), the research may be confounded. People who subscribe to CR are likely to be those who don’t smoke, who don’t drink to excess, who exercise, and who generally engage in a host of other behaviors designed to promote their health. Their results on medical tests do not indicate that CR is ultimately responsible for their good health.

Regarding Phelan’s point above, it’s unclear what the long-term effects of CR in human populations may be. From a psychological perspective, CR does not look much different (at least superficially) from a weight-loss diet. For those who are approaching CR for weight-loss purposes, we may see similar failure rates to other organized approaches that focus on deprivation. CR also looks a lot like the restriction associated with anorexia. Those involved in the CR movement emphasize that the goal is not weight loss and that nutrition takes a paramount role, unlike in anorexia. The Calorie Restriction Society takes a special look at CR vs. anorexia here. Still, eating-disordered thoughts and behaviors may creep up on the unsuspecting CR follower, particularly someone who focuses primarily on the associated weight-loss benefits. We may also see, as Phelan indicates, difficulty adhering to CR and compensatory bingeing, as a result of hunger and a reaction to a constricting, depriving diet without an end in sight.

Your thoughts?


PalmTreeChick said...

6 ft 115 lbs!! That's just gross, especially for a male!!

I don't see how CR can possibly be good for anyone.

PalmTreeChick said...

So I've been giving this some thought...

I don't think CR is a good idea, though I don't know much about it. It's kind of funny that I object to it when I partake in it myself. However, I think CR, when you have an ED is quite different from just CR, which you pointed out. People with EDs are restricting their calories because they want to be healthy and live longer. It's very much the opposite. Not they they don't want to be healthy, but it's a competely differnent mindset, again which you pointed it out. I just think it's kind of ironic how I can differentiate the two and think that CR is a strange and unhealthy way of living, yet but what I'm doing is ok.

Don't know if that made any sense.

elissa said...

it's a pursuit of health and longevity versus a pursuit of a thin ideal, regardless of the health ramifications. Though, being overly restrictive in any arena, to any end, strikes me as dangerous...even a little pathological? It makes orthorexia, though not a DSM disorder, seem a little more plausible.

littlem said...

"We may also see, as Phelan indicates, difficulty adhering to CR and compensatory bingeing, as a result of hunger and a reaction to a constricting, depriving diet without an end in sight."

This is the first thing that jumped into my head, especially given some of the thoughtful things commenters have said here.

Then I'm wondering about whether the coat of the simian on the left doesn't look as healthy as that of the simian on the right.

Then I wondered - Dr. S., by "national overeating challenge", were you referring to Thanksgiving? 'Cause what I realized right after I thought you might mean that is how I "save" my calories for the holidays; I only have dessert on Thanksgiving, Christmas, and New Year's. I've been doing that for at least five years, probably longer.

So I'm guessing that, however informally and minimally, the CR mindset, if not the actual lifestyle, might have already permeated our culture far more deeply than we might consciously realize.

BWT, Happy Holidays, everybody.

flowerchild said...

I have just finished reading a whole bunch of blogs written by us, people with EDs. We are the most self-centered people on earth with our focus on how we look, what we eat, we are too fat, we used to look skinnier, fatter, that person is fat, that person is skinny, blah, blah blah. They should give us our own planet because when we are so into our addiction, we are no good to this one. What a waste of our humanity.
To quote a song, "this is your life, are you who you want to be?" No I am not. And I am tired of it.
This evolution has come about slowly and the voices are still there; they probably always will be. But, I am refusing to listen to them. They are full of crap and reacting to their insanity is a death sentence physically and spiritually.
I know too much to go back.

My disgust is aimed at the disorder, not at us. Somehow we got entrenched in this dysfunction against our will, and before we knew what was happening we were in the middle of something out of control. My heart has broken for myself, my friends and for people I don't even know. All I can say is question it, fight it, wrestle it to the ground. Don't disappear. Don't slowly fade into the wallpapaer.
Who you are is worth fighting for.

PalmTreeChick said...

I agree somewhat with that flowerchild has to say, however, I disagree with the "self-centered" part to some extent. I understand partially what she's saying in that we do rule our lives with these thoughts, but it's not really us. I think if you were to look at the people with EDs, there some of the most caring people around, willing to do anything for anyone, which could work against them sometimes. It's not the person who is being self-centered, but the disease that is making them seem self-centered b/c the disease takes control.

drstaceyny said...

ptc--it is a v. low weight! See Elissa's comment below for a concise take on the difference.

elissa--you're right--there may be some overlap, too.

lm--"So I'm guessing that, however informally and minimally, the CR mindset, if not the actual lifestyle, might have already permeated our culture far more deeply than we might consciously realize."


Yep, I meant Thanksgiving. Hope you had a nice one.

fc/ptc--interesting discussion on the potential self-centeredness associated with EDs.

Anonymous said...

Interesting blog, but the title leaves me cold. Your contention that every woman has an eating disorder or some strange or strained relationship with food/body self-image/ appearance falls into the fallacy of extremes, words like all, none, every over describe a situation. I eat when I am hungry, avoid over eating and overly fatty or salty foods because I don't feel good when I give my body improper fuel, exercise (distance swimming, running, rowing, dog walking) often because it feeds my competitive nature and makes me sleep better/live better. I am a full time PhD student and work an additional 15 hours a week in a stressful job, yet i find time to cook, eat well and exercise. The emphasis in all things should be on becoming more in tune with ourselves, what drives us, what makes us content and satisfied. We strive to achieve success and competency in everything in life except in understanding our own selves- that is what i find missing in this dialogue. Appearances and fixation on them- that is a symptom not the root cause...

Anonymous said...

My grandmother lived to be 94, she didn't start slowing down until her last few years. I don't think she dieted a day in her life or knew the calorie content of anything. To me that's a better way to go. Unfortunately it's already too late for me not have done those things but I don't intend to live a more miserable life (even if longer) in which I can't enjoy the things I love.