Low-Calorie Diet Doesn’t Prolong Life, Study of Monkeys Finds

http://www.nytimes.com/2012/08/30/science/low-calorie-diet-doesnt-prolong-life-study-of-monkeys-finds.html

by tocomment • 14 years ago

57 65 14 years ago

Other article: http://news.ycombinator.com/item?id=4450307

There was a Univ of Wisconsin study, and an "Barshop Institute for Longevity and Aging Studies at the University of Texas Health Science Center in San Antonio" study, and their results contradict.

crpatino• 14 years ago

This is mentioned in the article, as well of some possible explanations why replication was not possible. My personal favorite is:

"The University of Wisconsin’s control monkeys were allowed to eat as much as they wanted and were fatter than those in the aging institute’s study, which were fed in amounts that were considered enough to maintain a healthy weight but were not unlimited."

rcthompson• 14 years ago

This would seen to suggest that although caloric restriction may not prolong life, an all-you-can-eat diet may shorten it.

rfugger• 14 years ago

I don't understand the problem with eating what you feel like when you're hungry, and stopping when you're full. You'd think a billion years of evolution would enable us to find a decent equilibrium by listening to our bodies. Obviously, it's the stopping when you're full part that's hard...

crusso• 14 years ago

Modern food availability and composition differs wildly from what we evolved on for 99.999% of that billion years.

It's not a big surprise that finding an equilibrium in this relatively new food and mobility environment is difficult for our species.

stephengillie3• 14 years ago

That would work if food were equally calorie dense. My stomach can hold about 3 cups of food most days. I can eat 3 cups of mashed potatoes (640 calories) or 3 cups of sugar (2326 calories) to feel full.

We didn't have processed cane sugar and refined vegetable oils during all those years of evolution.

enraged_camel6• 14 years ago

The feeling of satiety is not just a function of how full your stomach is. It's also a function of blood sugar levels. If you were eating sugar, you would start feeling full a lot sooner than if you were eating mashed potatoes. As a result, you would eat less of it in volume. (This is why sweet things are almost always served as desert, so they have a "topping off the satiety" effect as opposed to "killing the appetite before the real meal" effect.)

The danger here is calorie-dense fatty foods. Things like almonds and cashews are ridiculously easy to overeat, because they take up relatively little space and have a very tiny effect on blood sugar levels.

edit: wow, why the downvotes?

chc• 14 years ago

The trouble with this viewpoint is it seems to assume that evolution is optimizing for longevity. That fact is very much lacking from the evidence. Many creatures are literally programmed to die as soon as they finish reproducing. This is obviously not the case for humans, but it does show that evolution does not necessarily have our individual best interests at heart.

When we talk about longevity these days, we're not talking about living long enough to raise children — we're talking about living way past the point where we serve any clear evolutionary purpose. Thus, evolution might not be the best guide.

bunderbunder• 14 years ago

I find your dismissiveness to be disheartening. This isn't the usual fad diet nonsense. This is actually a finding that could be extremely interesting to researchers who work on longevity.

This study fits in with a large array of similar research on other species of mammals. Many of them have found that calorie restriction is associated with a significant extension of lifespan in the model species being used.

There's also some theoretical underpinnings that render the idea plausible. Free radicals are the cause of a number of processes that we collectively refer to as 'aging'. Since free radicals are a product of metabolizing, the reasoning goes that if you eat less you might produce less free radical in the first place, which in turn might lead to less aging.

If this study is accurate, then it suggests that the aging process in primates may not work quite the same way it does in rodents. And who knows where further research into something like that might go; at the very least learning more about primate biochemistry is a good way to figure out potential new treatments for human diseases.

billswift2• 14 years ago

In fact, calorie restriction doesn't even work well in rodents. One of the articles points out that whether calorie restriction "works" in mice depends on the lineage, some breeds it works and some it doesn't.

enraged_camel6• 14 years ago

Put simply, a billion years of evolution did not prepare us with thousands of calories of readily available, calorie dense (fast-)foods.

travisp• 14 years ago

Calorie-restricted diets that are being studied for life extension involve stopping before you're full. Other animal models had suggested that calorie-restriction would extend maximum lifespan beyond normal, anywhere from 20-50%. This is very different from just eating a normal healthy diet and stopping when you're full.

c0ff• 14 years ago

On the contrary, we overeat precisely because we listen to our bodies.

Evolution tuned us to survive in a world where food is scarce and periods of starvation are frequent. In the rare occasion that you have excess food, you eat it and build up fat reserves. The saved up fat will help you survive the period of starvation that undoubtedly follows.

rogerbinns• 14 years ago

So why isn't there a decline in appetite as the fat reserves grow? It won't matter while there are no side effects of adding more fat, but there seems to be a widespread belief that fat causes all sorts of health problems. At the least there is decreased mobility (more likely to be eaten by lions), earlier mortality (eg heart attacks) etc.

I wonder if there are any studies correlating obesity levels with reproductive success, and success of the offspring produced. That is what should end up controlling the genes and behaviour behind all this.

drumdance• 14 years ago

The problem is that a lot of people (myself included) are not very good at knowing when we're full.

philwelch4• 14 years ago

Supposedly, when you're full, you feel vaguely satisfied. When you actually feel full, you're actually overfull. When you feel stuffed, you're over-overfull.

herval3• 14 years ago

If you take the diet people used "a billion years" ago, it is definitely easier to control your hunger/cravings. But that would mean giving up on sugar (yup, juices and most fruit included), all sorts of bread and grains, potato, chocolate, beer, etc - all foods that alter your body levels and make self-control a struggle in the likes of an ex-smoker entering a room full of people smoking their lungs off.

TL;DR version: eating the right things can help you stopping when you're full...

josephlord• 14 years ago

A recent Horizon (BBC) documentary described some evidence that not everybody gets the 'full' signal in the same way or with the same strength.

If this is right then your advice will work for a significant proportion of the population (maybe even a majority) but that it won't work for everybody.

dfxm12• 14 years ago

I would argue that the point of a low-calorie diet isn't to live longer, but to look "better" (this, I guess depends on just how low the calorie count is).

A lot of the things we do "look healthy" doesn't make us live longer.

dclowd9901• 14 years ago

Looking better is a quality-of-life issue. Who wants to live forever if they are a gelatinous, amorphous blob.

jfoutz• 14 years ago

In the 90's free radicals were thought to do bad things, like cause cancer. One popular argument about calorie restriction was, fewer calories means fewer free radicals added to a body over decades. Since the damaging effects were stochastic, lowering the overall count by 10% should have lowered the overall frequency of "bad stuff" happening.

I know very little about nutrition, this is just how i recall the arguments.

endtime• 14 years ago

You're just talking about a totally different thing. Some people might restrict their caloric intake with the intent of losing weight, but independent of that, some people think that caloric restriction is good for longevity.

herval3• 14 years ago

"looking better" also includes being able to walk without a segway, fitting on the airplane seat, not breaking the plastic chairs at the barbecue party, not dying with clogged arteries when you're 30, not dying with a liver full of fat when you're 20...

I'm curious: what things that "look healthy" don't make us live longer?

tdfx2• 14 years ago

While I do agree that most attempts to "look better" will lead to better overall health, there's some ugly sides to that, as well: bulimia, anorexia, stimulant appetite suppressants, etc.

aezell7• 14 years ago

As someone who recently embarked on a restricted-calorie diet, I can say that I'm not inclined to live longer in the sense of past the average life-span. I'm more inclined to have a higher quality of life and live long enough to see my child into his adulthood.

That said, outside of weightloss and increased energy and stamina, I have noticed a few things about a reduced-calorie diet (and I'm talking 1000 calories or less most days):

1) I don't think about food as anything but fuel. I no longer think of it as a way to be social, to pass the time, or to be happy.

2) While it's possible to eat 1000 calories of calorie dense food with almost no other nutrition (sugar), I find that hunger demands I eat things that have more mass with less calories (vegetables and some proteins).

3) My day no longer revolves around eating. Pretty simple, but previously, I would be very concerned with what I had eaten the day before and might eat tomorrow. Outside of the measurements I'm keeping about caloric intake, I seldom think about food.

4) I'm saving money. I used to eat out a lot. Eating out, except for maybe a salad, makes it hard to reduce caloric intake. Now, I eat at home on the pound-for-pound cheaper food we can get at the farmer's market or grocery store.

enraged_camel6• 14 years ago

Can you elaborate on how a calorie-restricted diet can result in "increased energy and stamina"? Specifically, if your energy intake is minimal, how do you end up with more energy than you had in your previous diet?

ktizo• 14 years ago

Presumably, there is a peak efficiency of the digestive system where it is using the least energy in metabolism compared to the intake, which when combined with weighing less, so needing less energy to move, could mean that people eating relatively little in general could feel more energetic than someone eating far more. This becomes really obvious if you look at the upper end of the spectrum.

Evbn2• 14 years ago

Overeating causes hibernation like effects. like a bear, sleeping after eating.

manfredz2• 14 years ago

Your body is probably spending less time and energy digesting the food.

gwern4• 14 years ago

More calories doesn't translate straight into more energy or stamina, or athletes would just consume big blocks of lard.

mistercow• 14 years ago

"Energy" in the sense of "I have a lot of energy today" is only tangentially related to "energy" in the sense of "the energy content of this candy bar is 250 calories".

aezell7• 14 years ago

Most of the other replies here got the gist of what I wrote, but for me, it's about apparent energy levels. That is, because I don't feel weighed down and sluggish because of a huge, greasy meal, I'm more apt to get outside and play basketball with my son or go for a walk, etc.

amanvir• 14 years ago

I've been doing something similar, I eat 5 days a week and diet on two (less than 200 calories) in order to decrease body fat and it has been working out great, I can defiantly say that physically I'm more aesthetically pleasing and able to control my weight pretty well.

aezell7• 14 years ago

This is more of a fasting-type routine. I think there are some interesting studies being done on religious communities where this type of fasting is relatively common. I'd love to know what it feels like that first day after your diet days. Are you hungry? Can you eat much without feeling overfull? Do you feel sluggish or have trouble concentrating?

philwelch4• 14 years ago

> ...I'm more inclined to have a higher quality of life...

> ...I don't think about food as anything but fuel. I no longer think of it as a way to be social, to pass the time, or to be happy...

The problem for me is that what you're describing is not a higher quality of life at all. On the contrary, it sounds very impoverished.

aezell7• 14 years ago

Well, nobody said I don't eat foods I love on occasion and in moderation. For me, that moderation component is only achievable when I'm following a disciplined program the rest of the time. As to the notion of being impoverished by not having all the delicious foods in the world, that strikes me as a very aloof and distant connection with how the rest of the world lives.

I recently went to a county fair. While I tried to be mindful of what I was eating, I didn't deprive myself of the treats a fair has to offer. This is not about self-flagellation but about better self-awareness and in the end, hopefully about better health.

lukifer• 14 years ago

I made a different radical change in my diet: I doubled down on my love of food. Instead of getting jazzed by Taco Bell and Mountain Dew, now I savor for sautéed spinach and salmon. A major portion of my life now does resolve around food, including cooking, shopping and learning; that mindfulness and focus on quality allowed me to drop fifty-ish pounds in 4 months. (The cost difference of eating out and buying high-quality groceries is a wash, though.)

I say this not to vilify calorie-counting, just to illustrate that there are many valid approaches to health awareness. The most important things, I think, are to be mindful, to experiment, and to choose a lifestyle that is enjoyable and sustainable, rather than one of puritannical self-flagellation and inevitable binging.

aezell7• 14 years ago

I think there's a component of this to what I'm doing. My wife and I are often making very healthy, high-quality meals instead of fast food as you suggest. I don't think that has to equal more calories or any less enjoyment of food.

ihsw• 14 years ago

It's difficult to evaluate your calorie restricted diet without knowing macronutrient ratios (ie: ratio of fat/protein/carbohydrates), could you be elaborate on that?

aezell7• 14 years ago

Roughly speaking, it's about 25% fat, 40% carbs, 35% protein measured over the course of a week. I've recently added some light weight training to the exercise regimen and I'd like to increase that protein percentage to give my muscles the protein they need to build/repair. I have found that a lower percentage of fat doesn't really work well as it seems to throw my lipids out of balance (body overcompensation, perhaps?).

aezell7• 14 years ago

Given the replies, I thought I'd add in some details for context. On June 20, I weighed 338 pounds. I'm 6'2" tall and had a BMI of around 43. I was well past morbidly obese and had been for nearly a decade.

However, I had a vast number of tests and blood work run and the only apparent issue with any of those tests were some slightly elevated liver enzymes (fatty liver, as they say) likely because of the large amount of belly fat causing fat intrusions into the liver. Every other test was in the normal to better than normal range. Pretty incredible given my lifestyle.

I am a programmer and therefore sit in a chair a large amount of the day so my resting calorie consumption was pretty low. I did no exercise of any kind.

As I sit here this morning, I weigh 289 pounds and have a BMI of around 37. I still have a long way to go, but a calorie-restricted diet combined with moderate exercise (The first day I did 12 minutes on an elliptical at around 50 watts equaling something about half a mile. This morning I did 45 min. at around 75 watts equaling about 4.25 miles) has helped me made the progress I've made.

As for the diet, I started out at around 1600 calories a day. As I've progressed, that quota has decreased to around 1300 a day, though I typically eat less than 1000. While I track it on a daily/meal basis, I typically only analyze it at the week-by-week level.

I primarily use loseit.com to track and analyze all the data I capture.

delinka• 14 years ago

I didn't know anyone claimed longevity as a benefit of a low-calorie diet. I'd always heard "low-calorie" used to combat obesity. And less obesity == more longevity. But never "love longer on fewer calories." Whether this is scientific demonstrable is another matter entirely.

My personal theory is that avoiding gluttonous behavior will do you just fine. Stop when you're full. If you can do that, then you probably have the sensibilities to eat a well-rounded variety of foods. And you're done. That's it. Self-control & variety, Live Forever®

Evbn2• 14 years ago

A bunch of famous studies on mice found that caloric restriction added years to life. It was related to the oxidant/anti-oxident craze of the past decade or two.

herval3• 14 years ago

If it were really that simple, we'd have no fat people (me included). Compulsions are a hard thing to control, and if you add it to the fact that a lot of addicting substances are the basis of everyone's diets (sugar, salt, loads of carbs), then you see a compounding issue: personal/psychological issues + chemical stimulation from the food you eat = hopeless obesity...

fghh45sdfhr3• 14 years ago

I didn't know anyone claimed longevity as a benefit of a low-calorie diet.

I've heard that on both TV (PBS documentary) and all over the Internet. Not that I ever belied any of it, but I've heard it a lot.

mturmon• 14 years ago

Lots of people are now using CR in an attempt to prolong life.

Take a look at: http://www.crsociety.org/

gwern4• 14 years ago

Fulltext: http://dl.dropbox.com/u/85192141/2012-mattison.pdf

manfredz2• 14 years ago

Check out the recent BBC Horizon documentary on this very subject http://youtu.be/Pfna7nV7WaM

goggles99• 14 years ago

They should have fed these monkeys Highly processed, sugary foods and fast foods. Foods containing pesticides, low fiber and containing preservatives, antibiotics and growth hormones(a typical poor American diet). Then see which group loves longer.

This would have had far more value since it is truer to life at least for Westerners.

The less food you eat, the less wear on your organs right? the less toxins your body accumulates.

gwern4• 14 years ago

Why? That is of no scientific interest. Testing the specific phenomenon of caloric restriction - substantial lifespan increases from cuts in high quality diets - is of interest.

snogglethorpe• 14 years ago

"... if you're a monkey."

Low-Calorie Diet Doesn’t Prolong Life, Study of Monkeys Finds

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