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.
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.
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?
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.
There was a thread last week 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.
> 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.
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.
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.
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.
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.
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.
"Normal" varies a lot. Via my Oura ring, at 5'10" and 160lbs, I know I typically burn perhaps 250 cal on a lazy day off work. Against that background, working in retail management, ordinary numbers are 700 cal on an undemanding shift, and upwards of 1000 when it gets busy.
Correct. Apologies, as a sibling comment surmised, those numbers are for activity burn, in addition to BMR, for a total range that stretches from roughly 2000-3000 cal daily.
Yes, The basal metabolic rate of an average thirty years old man is probably between 2000kcal and 2500kcal. You most likely burn 350kcal a day due to your activity in addition to that. That’s still around 15%. Based on that I expect fluctuations of around 5% of your calories consumption between an active and a non active typical day (without exercising). That’s not massive but probably still noticeable.
So your body's immune system attacks some of the food you eat, starch is one of the only sugars you immune system doesnt attack, but not all foods are attacked.
Secondly some foods increase inflammation, some reduce it, when inflammation occurs, you could compliment it with chemicals/supps that are needed for cell regeneration, things like choline will help here, which is a chemical found in the cell wall, or if you reduce inflammation with things like painkillers, then look at what the painkillers are doing ie P450 enzymes.
There's loads of chemical & biological pathways in the body and you need to map out what they all do. Studies like this are just a snapshot of part of process and ideally you would sometimes need two or three studies using chemicals at different amounts to get a better idea. Chemistry will also help give insights into the chemical pathways, like how fast a reaction might take, things like that.
> we're conditioned to feel hungry three times a day,
Ghrelin is like an alarm clock, to break that eat at random times of the day.
> compulsively, or out of sheer boredom.
Stress, look at antioxidants, maybe a fruit juice and some stomp/jog/run around the block or down the street and back.
Probably the easiest way to get fit is little regular blasts of exercise, but you'll look like a fool to your neighbours. Little and often until fitness levels get up to something substantial. Some banks/city firms provided a gym at work for traders to go and have a quick 5-10min blast/exercise until exhaustion before returning to the desk to carry on, it could be weights, rowing machines and running machines, but its enough to release the pent up energy. This is why working from home or a small business could be harmful to your health. A good company with desk based work would lay on gym equipment, you need a minimum amount of exercise.
Starting from a high fitness level, a week dedicated to all waking hours doing a variety of exercises, saw my fitness levels substantially increased, like better than military PT instructor level.
I found, but YMMV, intense exercise until exhaustion is probably best, for example when doing some regular gym work, I'd do a sort of HIIT on weights, and only after about 6 months did I then start getting the urge to run and then I would run miles and miles on the treadmill. Just dont do anything which causes pain though which shows up straight away or after some sort of exercise.
Personally I'd knock back some vitamin K1 & K2-MK4 to protect your bones especially if older.
Even with no exercise if I don't eat enough I feel a little light headed, kind of floaty, and really tired and just overall in a bad mood. Not sure how people skip meals
The first time I even heard about caloric restriction I thought it was out there. I did eventually try intermittent fasting and after skipping breakfast and lunch I was rewarded with a pounding headache from the lack of my daily morning muffin and coffee.
Like a lot of difficult things it takes time and practise. I got better at doing it, but it's still really difficult, especially if the rest of your household don't practise it and you're seeing everyone else around you enjoying their usual meals and food treats.
Honestly I just think different humans are different. My wife gets light headed and can faint if she doesn't eat every 3-4 hours. I've fasted for multiple days without issue.
Agree. When I started skipping breakfast I got lightheaded after noon, but it went away after 1-2 week. Then there loss of hair which lasted 2-3 months. Now I can do 4-5 day fast without any major side effects.
When I’m at the lower end of my weight range, about 155lbs at 6’2” tall, I’m definitely like this.
When I’m at the upper end, about 170, it’s a lot better.
I think I’m basically just, close to that line by default, so not eating can really have adverse impacts on how I feel because I don’t have a lot of fat or muscle reserves.
I'm definitely what you would call "skinny fat" and unfortunately it's the worse it's ever been for me (that's why I'm overwright for the first time). I get anxiety when I feel even slightly hungry and then when I get my hands on food it makes me eat it too fast then I eat more than I should. Just started tracking my calories a few days ago and that's been huge
No idea why my body seems to go into panic mode when it gets hungry though with the extra 20ish pounds I've got
It's kinda natural to me, I have been doing what they today call intermittent fasting since I was a child. I guess everybody is different because I can't stand eating breakfast.
You can train your body to incredible lengths. I became much more sporty some 12-13 years ago. In the beginning, if I did some longer hike or skitour (3+hours with 1000+ altitude difference), I got pounding headache no matter how much water I drank. I was used to eating 3x per days too.
Rewind few years, doing many more (mostly mountain-related) sports/activities but cca 6x/week, I can wake up on rest day and go on without eating easily till evening without even noticing much difference, water/tea is enough. No headaches after sports unless I do something too intense or its too hot and I completely dehydrate myself. I still eat before some proper effort, didn't ever try doing them on empty stomach.
A friend of mine did interesting effort on his own - he is into half marathons and marathons, and learned his body to not rely on carbs but purely fat. So unlike many others in the races, he isn't replenishing quick sugars but just fat. He enjoys no glycemic swings but rather flat levels of energy
That feeling goes away with "practice". Starting IF it can feel like that for a while. I think it's your body getting more efficient at switching away from glucose and to ketones for energy production.
I sometimes wonder how much our language influences our behavior.
There are clearly somewhat distinct sensations that in my English-riddled mind all resolve to ‘hunger’. Then in my head i think ‘hmm, I’m hungry’ and so i do what i do when I’m ‘hungry’. I think this is what leads to me those curious moments where I’m standing in front of the refrigerator trying to remember how I got there.
I’ve recently started using ’snacky’ when i have that desire to crunch on something salty. As dumb as it sounds it has helped me ride it out vs mindlessly grabbing something from the pantry.
I became much more able to fast when I started supplementing with salt and magnesium and potassium in roughly the same quantities as my non-fasting diet (which includes a rather lot of salt, 5g+ per day).
In German, you say "Ich habe hunger", which literally means I have hunger. In my experience Germans are much more thin. I'm also inclined to think that it's (to some extent) because hunger is something they have, versus something they are.
In Danish (probably other norse languages too) there is "sulten" which means hungry and "lækkersulten" which translates to delicious-hungry, for when I feel a craving for something in particular.
It's a good point that explicitly distinguishing them might help. If I feel hungry, I might consciously stop and assess whether I'm legitimately hungry or only delicious-hungry.
Your body gets acclimated and expects three meals a day (+snacks if that how you were raised), anyone who has a pet and feed him at regular interval knows how it works. At that point it doesn't matter if you're hungry or not, your body will signal that you _need_ food. Most people follow what their body tells them without any after thought and that's how we get 70%+ of overweight people in the west.
Once people see food as fuel they usually have a whole different view on the topic.
Which wouldn't be an issue if you understand how your body works and get out of the ghrelin cycle, it's virtually impossible to overeat on IF and processed sugar is the last thing you'll crave once you're out of the addiction
Terrible food gets marketed to you all the time every day. TV, internet ads, highway billboards, subway panel ads, sides of buses, etc. Every time, you have to fight the added pressure of wanting to eat addictive crap and there's only so much strength the average person has been all the other daily pressures and concerns.
I'd bet that if all food ads were pushing leafy greens, the obesity rates would drop. It might take a generation or two.
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
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?
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.
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.
61 comments
[ 2.7 ms ] story [ 126 ms ] threadSo 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.
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.
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?
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-bd87-27c91611dd2...
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
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.
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.
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.
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.
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.
Secondly some foods increase inflammation, some reduce it, when inflammation occurs, you could compliment it with chemicals/supps that are needed for cell regeneration, things like choline will help here, which is a chemical found in the cell wall, or if you reduce inflammation with things like painkillers, then look at what the painkillers are doing ie P450 enzymes.
There's loads of chemical & biological pathways in the body and you need to map out what they all do. Studies like this are just a snapshot of part of process and ideally you would sometimes need two or three studies using chemicals at different amounts to get a better idea. Chemistry will also help give insights into the chemical pathways, like how fast a reaction might take, things like that.
> we're conditioned to feel hungry three times a day,
Ghrelin is like an alarm clock, to break that eat at random times of the day.
> compulsively, or out of sheer boredom. Stress, look at antioxidants, maybe a fruit juice and some stomp/jog/run around the block or down the street and back.
Probably the easiest way to get fit is little regular blasts of exercise, but you'll look like a fool to your neighbours. Little and often until fitness levels get up to something substantial. Some banks/city firms provided a gym at work for traders to go and have a quick 5-10min blast/exercise until exhaustion before returning to the desk to carry on, it could be weights, rowing machines and running machines, but its enough to release the pent up energy. This is why working from home or a small business could be harmful to your health. A good company with desk based work would lay on gym equipment, you need a minimum amount of exercise.
Starting from a high fitness level, a week dedicated to all waking hours doing a variety of exercises, saw my fitness levels substantially increased, like better than military PT instructor level.
Caveat. I'm not qualified in anything. JMO.
What does this mean? A blast of energy every hour? How many minutes?
Personally I'd knock back some vitamin K1 & K2-MK4 to protect your bones especially if older.
I literally had to go home from work to recover. I didn't try again until I saw this programme here in the UK: https://www.bbc.co.uk/programmes/b01lxyzc
Like a lot of difficult things it takes time and practise. I got better at doing it, but it's still really difficult, especially if the rest of your household don't practise it and you're seeing everyone else around you enjoying their usual meals and food treats.
When I’m at the upper end, about 170, it’s a lot better.
I think I’m basically just, close to that line by default, so not eating can really have adverse impacts on how I feel because I don’t have a lot of fat or muscle reserves.
No idea why my body seems to go into panic mode when it gets hungry though with the extra 20ish pounds I've got
Rewind few years, doing many more (mostly mountain-related) sports/activities but cca 6x/week, I can wake up on rest day and go on without eating easily till evening without even noticing much difference, water/tea is enough. No headaches after sports unless I do something too intense or its too hot and I completely dehydrate myself. I still eat before some proper effort, didn't ever try doing them on empty stomach.
A friend of mine did interesting effort on his own - he is into half marathons and marathons, and learned his body to not rely on carbs but purely fat. So unlike many others in the races, he isn't replenishing quick sugars but just fat. He enjoys no glycemic swings but rather flat levels of energy
There are clearly somewhat distinct sensations that in my English-riddled mind all resolve to ‘hunger’. Then in my head i think ‘hmm, I’m hungry’ and so i do what i do when I’m ‘hungry’. I think this is what leads to me those curious moments where I’m standing in front of the refrigerator trying to remember how I got there.
I’ve recently started using ’snacky’ when i have that desire to crunch on something salty. As dumb as it sounds it has helped me ride it out vs mindlessly grabbing something from the pantry.
It was an astounding revelation to me.
It's a good point that explicitly distinguishing them might help. If I feel hungry, I might consciously stop and assess whether I'm legitimately hungry or only delicious-hungry.
It's a vicious hormonal circle: https://en.wikipedia.org/wiki/Ghrelin
Your body gets acclimated and expects three meals a day (+snacks if that how you were raised), anyone who has a pet and feed him at regular interval knows how it works. At that point it doesn't matter if you're hungry or not, your body will signal that you _need_ food. Most people follow what their body tells them without any after thought and that's how we get 70%+ of overweight people in the west.
Once people see food as fuel they usually have a whole different view on the topic.
I'd bet that if all food ads were pushing leafy greens, the obesity rates would drop. It might take a generation or two.
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.h...
Google: https://www.google.com/search?q=intermittent+fasting+hacker+...
https://www.google.com/search?q=site%3Anews.ycombinator.com+...
Begs two questions - 1. why is the gene there? 2. turn off the gene, do people lose weight?
https://www.juvlabs.com/your-health/healthy-aging-lifestyle/...
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.