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"By slowing aging and increasing resistance to disease during periods of food scarcity, the adaptive responses to fewer calories increased the odds that animals

"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 17y ago
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 17y ago
  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.
joe_the_user 17y ago
Yeah, After a reading this article, http://hplusmagazine.com/articles/forever-young/eldorado-desperadoes-ii http://hplusmagazine.com/articles/forever-young/eldorado-des... I could see calorie restriction really had little basis and moreover, little logic, to it. But also, I'm 40+, 6', 135 pounds and I eat as much as I possibly can. I'm probably on the high of high metabolism. Losing 15% of body weight for me would, uh, really bad. And that's the thing, there's lot of genetic variation concerning gain weight propensity and a lot environmental variation concerning diet and level of activity. NONE of this is apparent in lab-animal studies. Lab animals are genetically uniform creatures who just sit around and eat dull food, even for a mouse (or monkey or whatever). If you've lived like a lab animal so-far, time to get out a bit but otherwise, the conclusions might not be warranted.
zeynel1 17y ago
I agree. All subjects interviewed in the article view this as a change in their diet. And calories and diet are not independent. The topic is very interesting. I searched for the original research paper but could not find it.
reasonattlm 17y ago
The benefits of calorie restriction are only partially caused by carrying less fat (specifically visceral fat that triggers higher levels of chronic inflammation). Here is a demonstration of what happens when you remove visceral fat from mice, for example. You get life extension, but not as much as calorie restriction: http://www.fightaging.org/archives/2008/03/lose-the-visceral-fat.php http://www.fightaging.org/archives/2008/03/lose-the-visceral... Calorie restriction is doing other things to metabolism as well. For example, autophagy is upregulated by calorie restriction. Upregulating autophagy by other means enhances life span. See: http://www.fightaging.org/archives/2009/10/attention-paid-to-autophagy.php http://www.fightaging.org/archives/2009/10/attention-paid-to... http://www.fightaging.org/archives/2007/10/calorie-restriction-and-autophagy.php http://www.fightaging.org/archives/2007/10/calorie-restricti... There are probably other line items as well, but given that calorie restriction doesn't work in animals with disabled autophagy mechanisms, it's the place to be looking. The plausible theory would be that increased autophagy cleans up damaged mitochondria, and mitochondrial function and damage are clearly very important determinants of longevity. See: http://www.fightaging.org/archives/2006/10/how-age-damaged-mitochondria-cause-your-cells-to-damage-you.php http://www.fightaging.org/archives/2006/10/how-age-damaged-m... http://www.fightaging.org/archives/2008/01/revisiting-skulachevs-laboratory.php http://www.fightaging.org/archives/2008/01/revisiting-skulac...

camccann 17y ago

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 17y ago
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.

joe_the_user 17y ago

Yeah, After a reading this article, http://hplusmagazine.com/articles/forever-young/eldorado-desperadoes-ii http://hplusmagazine.com/articles/forever-young/eldorado-des... I could see calorie restriction really had little basis and moreover, little logic, to it. But also, I'm 40+, 6', 135 pounds and I eat as much as I possibly can. I'm probably on the high of high metabolism. Losing 15% of body weight for me would, uh, really bad. And that's the thing, there's lot of genetic variation concerning gain weight propensity and a lot environmental variation concerning diet and level of activity. NONE of this is apparent in lab-animal studies. Lab animals are genetically uniform creatures who just sit around and eat dull food, even for a mouse (or monkey or whatever). If you've lived like a lab animal so-far, time to get out a bit but otherwise, the conclusions might not be warranted.

zeynel1 17y ago

I agree. All subjects interviewed in the article view this as a change in their diet. And calories and diet are not independent. The topic is very interesting. I searched for the original research paper but could not find it.

reasonattlm 17y ago

The benefits of calorie restriction are only partially caused by carrying less fat (specifically visceral fat that triggers higher levels of chronic inflammation). Here is a demonstration of what happens when you remove visceral fat from mice, for example. You get life extension, but not as much as calorie restriction: http://www.fightaging.org/archives/2008/03/lose-the-visceral-fat.php http://www.fightaging.org/archives/2008/03/lose-the-visceral... Calorie restriction is doing other things to metabolism as well. For example, autophagy is upregulated by calorie restriction. Upregulating autophagy by other means enhances life span. See: http://www.fightaging.org/archives/2009/10/attention-paid-to-autophagy.php http://www.fightaging.org/archives/2009/10/attention-paid-to... http://www.fightaging.org/archives/2007/10/calorie-restriction-and-autophagy.php http://www.fightaging.org/archives/2007/10/calorie-restricti... There are probably other line items as well, but given that calorie restriction doesn't work in animals with disabled autophagy mechanisms, it's the place to be looking. The plausible theory would be that increased autophagy cleans up damaged mitochondria, and mitochondrial function and damage are clearly very important determinants of longevity. See: http://www.fightaging.org/archives/2006/10/how-age-damaged-mitochondria-cause-your-cells-to-damage-you.php http://www.fightaging.org/archives/2006/10/how-age-damaged-m... http://www.fightaging.org/archives/2008/01/revisiting-skulachevs-laboratory.php http://www.fightaging.org/archives/2008/01/revisiting-skulac...