
The Calorie-Restriction Experiment - ars
http://www.nytimes.com/2009/10/11/magazine/11Calories-t.html
======
latortuga
"By slowing aging and increasing resistance to disease during periods of food
scarcity, the adaptive responses to fewer calories increased the odds that
animals and humans that lived short lives might survive until they could
reproduce."

This statement seems somewhat dangerous to me. If the body slows down because
of lack of resources, I'm willing to bet that, like has been observed in
animals, fertility will also drop off - you don't reproduce when resources are
scarce.

The article seems kind of contradictory to me. They say that it isn't a study
about weight loss but then go on to say that this diet has an effect on
lifespan in part because of the effect of aging diseases (cancer,
cardiovascular disease, diabetes) which are all highly correlated with being
overweight. Weight loss therefore has to be one of the primary goals of the
study - if it didn't help you lose weight then it wouldn't (by definition) be
reducing your risk factors for those diseases.

~~~
camccann
_This statement seems somewhat dangerous to me. If the body slows down because
of lack of resources, I'm willing to bet that, like has been observed in
animals, fertility will also drop off - you don't reproduce when resources are
scarce._

I think the idea is that the animals would have a better chance of surviving
until food became plentiful again, at which point their intake would return to
normal along with fertility and aging.

~~~
latortuga
Oh I don't disagree but I mean to point out that engaging in a calorie
restricting diet at a young age may be detrimental to fertility, based on the
effects that they suggest and the observational evidence from other animals.
This may or may not be a big deal to certain people depending on goals - if
you want to have children in your 20s versus 30s for example.

------
abhay
There are some review articles that are very readable for non-scientists
written by an old boss of mine (Dr. Mark Mattson at the National Institute on
Aging) on dietary intake.

Here are some:

Dietary factors, hormesis and health
[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2253665?tool=pub...](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2253665?tool=pubmed)

Impact of energy intake and expenditure on neuronal plasticity.
[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2635925/?tool=pu...](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2635925/?tool=pubmed)

Mattson is an interesting (albeit, a bit harebrained) dude. He completely
believes in this caloric restriction stuff so much that he lives the lifestyle
and follows a really strict diet.

~~~
joe_the_user
Hmm,

Do you know if there have been any studies which made an effort to distinguish
average-weight and average calorie intake? Hight calorie intake is associate
with obesity and obesity is associated with many health problems. But what is
the cause and what is the effect?

Do, say, long distance athletes, who consume and use massive calorie levels,
suffer the same health problems as overweight sedentary people? Seriously, I'm
curious if people have looked this.

------
zeynel1
If the subject is losing weight then he/she is getting low calories and the
body is burning excess fat. The diet then can be adjusted by trial and error
and the subject can find the right diet and the right amount. The golden rule
is to eat as much non-processed food as possible. I believe that these
professional doctors hyper-complicated the process. Dieters usually hate to
count calories.

~~~
zck
Natrius is right. The independent variable in this experiment is calories
ingested, not weight loss. They're specifically testing for what happens when
you eat fewer calories. On page six, they compare rats that are lean because
of exercise with rats that are lean because of calorie restriction. "...only
calorie restriction was able to slow down aging and increase maximal life
span." Simply having the participants lose weight would not allow as much to
be learned about what they are studying. Complex controls are paramount for
these human studies.

