There is a similar confound for intermittent fasting: if the IF animals lose weight, then that strongly implies that they were not doubling up on their feeding or whatever they needed to do to eat a normal amount of calories. Hence, weight loss + longevity increase ceases to be evidence for IF, and becomes evidence for CR.
There is a similar confound for intermittent fasting: if the IF animals lose weight, then that strongly implies that they were not doubling up on their feeding or whatever they needed to do to eat a normal amount of calories.
Some intermittent fasting studies have controlled for calorie intake, though. For example, this one:
It doesn’t entirely rule out the possibility of reduced calorie intake being responsible - since consumed calories may not result is absorbed calories so reliably on intermittent fasting regimes. However, most explanations seem to focus on the more persistently lowered blood glucose levels and/or the increased stress.
Could you clarify this just a bit? I practice IF for health reasons, so I’m quite interested in learning if it’s bunk. I was under the impression that the whole point was that in induces essentially the same effects as CR but without needing to worry about calorie-counting, etc. It’s just automatic. Is that what you meant to say? Or are you pointing toward evidence against IF such that people like me who are interested in longevity should consider stopping?
My personal experience with IF suggests that there are pretty major benefits from doing it regularly. I lost 30 pounds (and I had no idea I needed to lose them—but I definitely look and feel much better!), my general levels of inflammation dropped, my energy stabilized, and my various biomarkers went from good to excellent. And I’m no longer trapped by a regular need for food; if it takes an extra three hours or so to get to a meal, it doesn’t really affect me.
But I’ve seen this warning about sudden adult-onset CR shortening lifespan, and I see in this article you link to that it’s apparently an issue with IF too. That concerns me. I switched to IF over the course of about a week. Does anyone know what the mechanism for shortening lifespan with too quick an adaptation to CR is? If there’s some way of checking for that kind of damage or ongoing effect in myself, I’d like to do so.
And is it a matter of “once done, you’ve done the damage and it’s too late,” or is it more that ongoing CR that started too suddenly keeps affecting the organism in negative ways, kind of like getting continually exposed to cold air actually inhibits circulation rather than strengthening it if the initial burst of cold was too strong? That difference would matter a lot to me because if IF isn’t really having any negative longevity effects, I’d still want to keep doing it because the other benefits I’m getting from it are so pragmatically awesome. But if I’m continually cutting months off my life, I’ll stop right away!
I’m afraid I don’t really know. Intermittent fasting, like masturbation, is something I’m still collecting citations and quotes on because no clear picture has emerged for me.
There is a similar confound for intermittent fasting: if the IF animals lose weight, then that strongly implies that they were not doubling up on their feeding or whatever they needed to do to eat a normal amount of calories. Hence, weight loss + longevity increase ceases to be evidence for IF, and becomes evidence for CR.
Some intermittent fasting studies have controlled for calorie intake, though. For example, this one:
Intermittent fasting dissociates beneficial effects of dietary restriction on glucose metabolism and neuronal resistance to injury from calorie intake.
It doesn’t entirely rule out the possibility of reduced calorie intake being responsible - since consumed calories may not result is absorbed calories so reliably on intermittent fasting regimes. However, most explanations seem to focus on the more persistently lowered blood glucose levels and/or the increased stress.
Could you clarify this just a bit? I practice IF for health reasons, so I’m quite interested in learning if it’s bunk. I was under the impression that the whole point was that in induces essentially the same effects as CR but without needing to worry about calorie-counting, etc. It’s just automatic. Is that what you meant to say? Or are you pointing toward evidence against IF such that people like me who are interested in longevity should consider stopping?
http://www.longecity.org/forum/topic/27757-alternate-day-fasting-only-works-with-calorie-restriction/
Ah! Thank you. So the short version is:
IF is a riskier method of doing CR
You still have to have the net effect of CR
My personal experience with IF suggests that there are pretty major benefits from doing it regularly. I lost 30 pounds (and I had no idea I needed to lose them—but I definitely look and feel much better!), my general levels of inflammation dropped, my energy stabilized, and my various biomarkers went from good to excellent. And I’m no longer trapped by a regular need for food; if it takes an extra three hours or so to get to a meal, it doesn’t really affect me.
But I’ve seen this warning about sudden adult-onset CR shortening lifespan, and I see in this article you link to that it’s apparently an issue with IF too. That concerns me. I switched to IF over the course of about a week. Does anyone know what the mechanism for shortening lifespan with too quick an adaptation to CR is? If there’s some way of checking for that kind of damage or ongoing effect in myself, I’d like to do so.
And is it a matter of “once done, you’ve done the damage and it’s too late,” or is it more that ongoing CR that started too suddenly keeps affecting the organism in negative ways, kind of like getting continually exposed to cold air actually inhibits circulation rather than strengthening it if the initial burst of cold was too strong? That difference would matter a lot to me because if IF isn’t really having any negative longevity effects, I’d still want to keep doing it because the other benefits I’m getting from it are so pragmatically awesome. But if I’m continually cutting months off my life, I’ll stop right away!
I’m afraid I don’t really know. Intermittent fasting, like masturbation, is something I’m still collecting citations and quotes on because no clear picture has emerged for me.
Drat. Well, do keep me posted, and I’ll keep an eye out for similar info.