6 ms·

Caloric restriction in humans reveals immunometabolic regulators of health span

159 points by WaitWaitWha 5y ago

nradov 5y ago
I can't read the full article, but the abstract didn't mention anything about the effects of the caloric restriction protocol on the muscle mass of human subjects. This is why I'm very skeptical that it will actually work to extend human lifespans. We know that sarcopenia increases the risk of serious falls for elderly people. And any physician can tell you how a bad fall frequently causes loss of mobility, and sets off a chain of physical declines leading to death in a couple years. So personally I'm going to contine eating a lot of calories, and doing a lot of hard exercise. Maybe I'll age faster but at least I won't be frail.
- gloryjulio 5y ago
  I think you will be fine unless you are over trained. As long as your cico is balanced, I don't think there is anything wrong with that.
  - inter_netuser 5y ago
    cico?
    - ilija139 5y ago
      calories in, calories out
    - lvturner 5y ago
      calories in, calories out
    - puchatek 5y ago
      Counting calories in, calories out.
- xwdv 5y ago
  You won’t age faster. The exercise will train your body to become more resistant to oxidation and you will delay morbidity right up until the day you actually die. Cartilage wear and tear is the only thing that will really slow you down and put you on a spiral of being unable to exercise effectively and thus getting frailer. But maybe we will discover ways to regrow cartilage. I’d say the fasting method is just another alternative for people to combat aging if they don’t feel like working out, but you can’t mix the two methods. Choose one path or the other.
- ilija139 5y ago
  It says caloric restriction without malnutrition. Eating 15% less carb and fat calories won't make you loose any more muscle mass than you would have otherwise. But I am wondering my self too, what's the effect when you combine CR with exercise. 15% out of 2000 calories is 300 cal or about 30 mins jogging. So instead of eating less, will the effect be similar if I spend 300 cal more everyday through exercise?
  - nradov 5y ago
    Malnutrition is a vague term that can mean many different things. You can lose significant muscle mass even if you aren't technically malnourished. You absolutely can lose muscle mass if you cut carb and fat calories below a certain threshold. Whether that threshold is above or below 15% depends on many factors. The Real Science of Sport podcast has a good explanation of how this works. https://play.acast.com/s/f3fb5c75-b943-4f5d-bd87-27c91611dd24/620bd160e1582b0013263859 https://play.acast.com/s/f3fb5c75-b943-4f5d-bd87-27c91611dd2...
  - stevenwoo 5y ago
    There was a thread last week https://news.ycombinator.com/item?id=30381000 https://news.ycombinator.com/item?id=30381000 that discussed scientist(s) doing studies that debunk the theory that burning more calories during exercise leads to weight loss - your body compensates by burning fewer calories at rest so the daily calorie budget your body needs stays more or less constant for vast majority (possibly all) of people and exercise/diet combinations.
- thefz 5y ago
  > effects of the caloric restriction protocol on the muscle mass of human subjects Some think it's a myth. It makes sense if you think about it, the body uses a lot of energy and resources to build muscle (and tendons, and to mineralize bones) only to destroy it right away at the first intake dip, not even considering the primary source for energy storage, which is fat? Caloric restriction burns A LOT of fat. It's why it's there in the first place. https://www.dietdoctor.com/does-fasting-burn-muscle https://www.dietdoctor.com/does-fasting-burn-muscle
- mdorazio 5y ago
  Here's a meta-analysis with some actual data from researchers: https://www.jscimedcentral.com/SportsMedicine/sportsmedicine-8-1180.pdf https://www.jscimedcentral.com/SportsMedicine/sportsmedicine... The research seems to show that if you're trying to be muscular, CR is probably not going to help you. However, CR actually has some positive effects on exercise performance and outcomes for activities that don't revolve around raw strength. Unfortunately, there's very little research on CR vs. strength training in people who are not elderly and not overweight. I share your frustration there - so much of the hype around CR comes from it being an easy solution for people who are not already physically fit.
- ericmcer 5y ago
  I don't think calorie restriction will lead to you breaking your hip because you are so emaciated. I think the current status of fitness (going to the gym and lifting weights then eating a bunch of protein) is a totally backward approach to health and exercise. If you want to be muscular for aesthetic reasons that is totally valid, but it is misleading to pretend it is healthy. This is coming from someone who did tons of hard exercise from 16-26 then completely reworked my approach from intensity to volume, started restricting calories and reduced protein intake. That said fitness is a journey and you should always be willing to completely reverse everything you think you know.
ciconia 5y ago
IANAE, can only talk from personal experience and observing the people around me. Having started practicing intermittent fasting recently, one of the most interesting aspects of the experience is to see how my body's needs change according to my level of physical activity. On days when I'm not physically active, it's quite astonishing how little fuel my body needs. We're all (in developed countries at least) raised on having three meals a day, day in day out, without much consideration for whether our body needs it. In fact, we're conditioned to feel hungry three times a day, regardless of whether we really need to eat. I've also noticed how many people (myself included) would eat compulsively, or out of sheer boredom.
- ramraj07 5y ago
  Intermittent fasting is not caloric restriction though.
  - awb 5y ago
    It doesn’t have to be, but in practice it helps restrict calories by eliminating late night snacking. Or if you fast for an entire day and don’t overeat during your other feeding windows to compensate you can also find yourself in a caloric deficit.
  - thefz 5y ago
    It is. IF should be combined with a diet richer in protein and fat, and poorer in carbs. In the case of OMAD it's also harder to reach the full caloric budget of a day in a single setting.
- deleted 5y ago
  [deleted]
- PragmaticPulp 5y ago
  Normal daily physical activity (not hours of cardio at the gym) isn’t responsible for a huge part of your typical caloric expenditure. If you’re noticing a large difference, it’s likely due to appetite related changes or even simply perception differences, not actual energy expenditure changes.
ck2 5y ago
Well yes, if you "starve" cells, you also starve things like cancerous cells. Good luck getting modern society to "calorie restrict" beyond single digit percentage of population. But there are even lower hanging fruit on the "health and longevity" tree. Go read about protein glycosylation (where sugar attached to proteins) vs aging and chronic inflammation. Most animal proteins do not have (enough) glycine in them. Dunno which source to link on this as there are thousands but maybe start here as a more layperson explainer and check google scholar for more if interested https://www.sciencedaily.com/releases/2015/05/150526085138.htm https://www.sciencedaily.com/releases/2015/05/150526085138.h...
mgh2 5y ago
HN: https://hn.algolia.com/?q=%09Intermittent+fasting https://hn.algolia.com/?q=%09Intermittent+fasting Google: https://www.google.com/search?q=intermittent+fasting+hacker+news&oq=intermittent+fasting+hacker+news&aqs=edge.0.0i512j69i57j69i64.5892j0j1&sourceid=chrome&ie=UTF-8 https://www.google.com/search?q=intermittent+fasting+hacker+...
- gernb 5y ago
  If you just want hacker news results then https://www.google.com/search?q=site%3Anews.ycombinator.com+intermittent+fasting https://www.google.com/search?q=site%3Anews.ycombinator.com+...
lifeisstillgood 5y ago
So do I understand this right? There is a gene (PLA2G7) that when turned off in mice, mimiced the immune / other improvements that they saw in humans who were dieting - in other words turn off this gene and get some of the (life extension) benefits of dieting? Begs two questions - 1. why is the gene there? 2. turn off the gene, do people lose weight?
- karrot-kake 5y ago
  Why the gene is there is a complex question. It may be part of some other metabolic pathways, or it may be just a way evolution found to fulfill a function of the cell. About turning it off, this approach is again, complex. We need to perform knock-out experiments in model organisms first, to understand the overall function of the gene.
unfocussed_mike 5y ago
I am not sure if it is middle age or grammar school upbringing that makes the term "health span" so uncomfortable to read.
- Johnny555 5y ago
  health span and life span are different, and arguably, the health span is more important. https://www.juvlabs.com/your-health/healthy-aging-lifestyle/article/healthspan-vs-lifespan https://www.juvlabs.com/your-health/healthy-aging-lifestyle/...
NorSoulx 5y ago
I've been practicing intermittent fasting for close to 2 years, with a 2-6 hour eating window each day. Most of the time the fasting period has been around 20 hours a day. For a month now I've switched to one meal a day (OMAD), only eating dinner with the family. I only eat home made low carb meals. Being 50+ I've been able to keep the weight in check, BMI now 22.3. Hunger or lack of energy is not a problem, it's more the I sometimes out of "boredom" want to eat to pass time. But since I do not want to break the routine, it keeps me from snacking. I always feel a state of "serenity" during the fasting periods.
morekozhambu 5y ago

159 points by WaitWaitWha 5y ago

I can't read the full article, but the abstract didn't mention anything about the effects of the caloric restriction protocol on the muscle mass of human subjects. This is why I'm very skeptical that it will actually work to extend human lifespans. We know that sarcopenia increases the risk of serious falls for elderly people. And any physician can tell you how a bad fall frequently causes loss of mobility, and sets off a chain of physical declines leading to death in a couple years. So personally I'm going to contine eating a lot of calories, and doing a lot of hard exercise. Maybe I'll age faster but at least I won't be frail.

gloryjulio 5y ago
I think you will be fine unless you are over trained. As long as your cico is balanced, I don't think there is anything wrong with that.
- inter_netuser 5y ago
  cico?
  - ilija139 5y ago
    calories in, calories out
  - lvturner 5y ago
    calories in, calories out
  - puchatek 5y ago
    Counting calories in, calories out.
xwdv 5y ago
You won’t age faster. The exercise will train your body to become more resistant to oxidation and you will delay morbidity right up until the day you actually die. Cartilage wear and tear is the only thing that will really slow you down and put you on a spiral of being unable to exercise effectively and thus getting frailer. But maybe we will discover ways to regrow cartilage. I’d say the fasting method is just another alternative for people to combat aging if they don’t feel like working out, but you can’t mix the two methods. Choose one path or the other.
ilija139 5y ago
It says caloric restriction without malnutrition. Eating 15% less carb and fat calories won't make you loose any more muscle mass than you would have otherwise. But I am wondering my self too, what's the effect when you combine CR with exercise. 15% out of 2000 calories is 300 cal or about 30 mins jogging. So instead of eating less, will the effect be similar if I spend 300 cal more everyday through exercise?
- nradov 5y ago
  Malnutrition is a vague term that can mean many different things. You can lose significant muscle mass even if you aren't technically malnourished. You absolutely can lose muscle mass if you cut carb and fat calories below a certain threshold. Whether that threshold is above or below 15% depends on many factors. The Real Science of Sport podcast has a good explanation of how this works. https://play.acast.com/s/f3fb5c75-b943-4f5d-bd87-27c91611dd24/620bd160e1582b0013263859 https://play.acast.com/s/f3fb5c75-b943-4f5d-bd87-27c91611dd2...
- stevenwoo 5y ago
  There was a thread last week https://news.ycombinator.com/item?id=30381000 https://news.ycombinator.com/item?id=30381000 that discussed scientist(s) doing studies that debunk the theory that burning more calories during exercise leads to weight loss - your body compensates by burning fewer calories at rest so the daily calorie budget your body needs stays more or less constant for vast majority (possibly all) of people and exercise/diet combinations.
thefz 5y ago
> effects of the caloric restriction protocol on the muscle mass of human subjects Some think it's a myth. It makes sense if you think about it, the body uses a lot of energy and resources to build muscle (and tendons, and to mineralize bones) only to destroy it right away at the first intake dip, not even considering the primary source for energy storage, which is fat? Caloric restriction burns A LOT of fat. It's why it's there in the first place. https://www.dietdoctor.com/does-fasting-burn-muscle https://www.dietdoctor.com/does-fasting-burn-muscle
mdorazio 5y ago
Here's a meta-analysis with some actual data from researchers: https://www.jscimedcentral.com/SportsMedicine/sportsmedicine-8-1180.pdf https://www.jscimedcentral.com/SportsMedicine/sportsmedicine... The research seems to show that if you're trying to be muscular, CR is probably not going to help you. However, CR actually has some positive effects on exercise performance and outcomes for activities that don't revolve around raw strength. Unfortunately, there's very little research on CR vs. strength training in people who are not elderly and not overweight. I share your frustration there - so much of the hype around CR comes from it being an easy solution for people who are not already physically fit.
ericmcer 5y ago
I don't think calorie restriction will lead to you breaking your hip because you are so emaciated. I think the current status of fitness (going to the gym and lifting weights then eating a bunch of protein) is a totally backward approach to health and exercise. If you want to be muscular for aesthetic reasons that is totally valid, but it is misleading to pretend it is healthy. This is coming from someone who did tons of hard exercise from 16-26 then completely reworked my approach from intensity to volume, started restricting calories and reduced protein intake. That said fitness is a journey and you should always be willing to completely reverse everything you think you know.

ciconia 5y ago

IANAE, can only talk from personal experience and observing the people around me. Having started practicing intermittent fasting recently, one of the most interesting aspects of the experience is to see how my body's needs change according to my level of physical activity. On days when I'm not physically active, it's quite astonishing how little fuel my body needs. We're all (in developed countries at least) raised on having three meals a day, day in day out, without much consideration for whether our body needs it. In fact, we're conditioned to feel hungry three times a day, regardless of whether we really need to eat. I've also noticed how many people (myself included) would eat compulsively, or out of sheer boredom.

ramraj07 5y ago
Intermittent fasting is not caloric restriction though.
- awb 5y ago
  It doesn’t have to be, but in practice it helps restrict calories by eliminating late night snacking. Or if you fast for an entire day and don’t overeat during your other feeding windows to compensate you can also find yourself in a caloric deficit.
- thefz 5y ago
  It is. IF should be combined with a diet richer in protein and fat, and poorer in carbs. In the case of OMAD it's also harder to reach the full caloric budget of a day in a single setting.
deleted 5y ago
[deleted]
PragmaticPulp 5y ago
Normal daily physical activity (not hours of cardio at the gym) isn’t responsible for a huge part of your typical caloric expenditure. If you’re noticing a large difference, it’s likely due to appetite related changes or even simply perception differences, not actual energy expenditure changes.

ck2 5y ago

Well yes, if you "starve" cells, you also starve things like cancerous cells. Good luck getting modern society to "calorie restrict" beyond single digit percentage of population. But there are even lower hanging fruit on the "health and longevity" tree. Go read about protein glycosylation (where sugar attached to proteins) vs aging and chronic inflammation. Most animal proteins do not have (enough) glycine in them. Dunno which source to link on this as there are thousands but maybe start here as a more layperson explainer and check google scholar for more if interested https://www.sciencedaily.com/releases/2015/05/150526085138.htm https://www.sciencedaily.com/releases/2015/05/150526085138.h...

mgh2 5y ago

HN: https://hn.algolia.com/?q=%09Intermittent+fasting https://hn.algolia.com/?q=%09Intermittent+fasting Google: https://www.google.com/search?q=intermittent+fasting+hacker+news&oq=intermittent+fasting+hacker+news&aqs=edge.0.0i512j69i57j69i64.5892j0j1&sourceid=chrome&ie=UTF-8 https://www.google.com/search?q=intermittent+fasting+hacker+...

gernb 5y ago
If you just want hacker news results then https://www.google.com/search?q=site%3Anews.ycombinator.com+intermittent+fasting https://www.google.com/search?q=site%3Anews.ycombinator.com+...

lifeisstillgood 5y ago

So do I understand this right? There is a gene (PLA2G7) that when turned off in mice, mimiced the immune / other improvements that they saw in humans who were dieting - in other words turn off this gene and get some of the (life extension) benefits of dieting? Begs two questions - 1. why is the gene there? 2. turn off the gene, do people lose weight?

karrot-kake 5y ago
Why the gene is there is a complex question. It may be part of some other metabolic pathways, or it may be just a way evolution found to fulfill a function of the cell. About turning it off, this approach is again, complex. We need to perform knock-out experiments in model organisms first, to understand the overall function of the gene.

unfocussed_mike 5y ago

I am not sure if it is middle age or grammar school upbringing that makes the term "health span" so uncomfortable to read.

Johnny555 5y ago
health span and life span are different, and arguably, the health span is more important. https://www.juvlabs.com/your-health/healthy-aging-lifestyle/article/healthspan-vs-lifespan https://www.juvlabs.com/your-health/healthy-aging-lifestyle/...

NorSoulx 5y ago

I've been practicing intermittent fasting for close to 2 years, with a 2-6 hour eating window each day. Most of the time the fasting period has been around 20 hours a day. For a month now I've switched to one meal a day (OMAD), only eating dinner with the family. I only eat home made low carb meals. Being 50+ I've been able to keep the weight in check, BMI now 22.3. Hunger or lack of energy is not a problem, it's more the I sometimes out of "boredom" want to eat to pass time. But since I do not want to break the routine, it keeps me from snacking. I always feel a state of "serenity" during the fasting periods.

morekozhambu 5y ago