#1

Feel free to delete this if it’s been covered already.
I understand how CR would increase longevity and I personally am not interested in doing CR, but I’d like to understand how you do it long term?

The goal is obviously to be in negative caloric balance.
If you overdo that you lose too much lean tissue and become unhealthy.
Anything less than too much, you lose weight, but your body will do everything it can to adapt, become more efficient and need fewer calories. So - you would have to steadily keep reducing your calorie intake to stay in negative balance. Where does this stop? Do you get too thin? Do you get down to zero calories in? Who has done this for years?

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#2

They don’t keep reducing calorie intake in the animal studies I don’t think, as obviously that would be starvation.
They just remove 20% of what the animals typically eat ad libitum, or whatever number it is.
Your best bet would be to look at what they do in those studies.

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#3

I’ve done pretty aggressive CR for some 8 years or so, then gradually backed off, but I still don’t overeat.

I got to about 1450 calories a day and stabilized at that level, BMI of about 18. That’s all. Then you just cruise along at that level. Weight loss stabilizes, and you just keep going. I never pushed my calories too low, just never felt there was a reason. I pushed to the point where I still felt excellent, but not lower, and that happened to fall somewhere around 1400-1500 calories a day for me.

Yes, the body adapts, you tend to be cold as your body temp drops - think sweater anywhere below 80 F or so (at the doctor’s they’d always think they must have made a mistake with the thermometer, my core temp was so low, lol), but become quite heat tolerant, which is useful in SoCal :slight_smile: - people turn on the AC, but you are quite fine at 95F. Your BP drops dramatically, to the point of occasional orthostatic hypotension. There’s a wide array of reaction to CR, a lot of people are hungry all the time. I happen not to get hungry. But you do tend to develop an obsession with food, and if you allow yourself an occassional “CR holiday”, f.ex. while travelling on vacation, you can easily go overboard and really scarf it down (that was my problem - it felt like being let off the chain!).

My biomarkers were pretty stellar… except LDL and TC, always high genetically.

I eventually eased off CR, because it became just too much of a hassle - never being able to socialize around food (picture Thanksgiving, having to beg off with a salad - you just become a weird freak), always having to carefully weigh all your food items, very restrictive diet, never spontaneous around food (hey, let’s try that new restaurant… not!). I felt like I was in a kind of permanent prison. It just wears you down. Others seem to be fine indefinitely, but I had enough after about 8 years or so.

While on CR, I didn’t exercise, except for some hiking in the hills on weekends, and I was pretty thin, but oddly never felt “weak” - quite the opposite, felt very strong and capable, and all the senses were razor sharp. I felt strong, very fast and sharp. Today I exercise regularly, fairly solidly, and don’t feel a fraction as strong, fast and sharp. I remember a study where they showed that the bones on CR had a lower density score, yet were stronger, and it was speculated that it was because the CR bones had a superior quality, as if all the subpar cells that were bulking up the density got discarded and only the best retained and augmented. Same with muscle size - the relationship of size to strength and power is not 1:1:1. Many much slimmer (less hypertrophic muscles) are stronger than the mass monsters gram for gram - muscle quality matters.

In any case, somehow on CR, muscle size, conditioning, strength, never were an issue. I never had an issue with activities of daily living - need to lift a 150lb suitcase, sure, no problem! This btw. was borne out by CR studies, where the longest lived highly restricted animal were not exercising at all, but were never frail, and looked good right until the end. CR beats out exercise for health and longevity all day long.

If you can hack it, CR is great. The problem is partially psychological, but mostly social - our society is just not built to be CR lifestyle friendly. Lot of downsides, you can become isolated, even shunned; appearance not good - the opposite sex is not allured by a gaunt looking person. Very hard lifestyle to pull off - unless you have millions and millions perhaps.

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#4

All true, and the same from my experience. I wouldn’t assume bones are stronger even though BMD is lower though.

What might be the solution for the bone mass density is to have a lot more muscle mass, strength training and eating adequate protein from lean proteins. That way you have mass to keep bones stronger (with adequate calcium intake). BMI is highly related to bone mass density, if your BMI is low that increases fracture risk over time. So a high BMI on CR is probably very important as you don’t want your hip to snap in half leading to a 50% risk of death in 1 year from sepsis and other infections, etc. A too low CR is probably not a good idea unless someone wants to supplement or use hormones, but that can be monitored.

The CR being might be a different breed, if optimized to prevent the downsides.

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#5

Like I said, there was a study showing CR bones with lower BMD, but stronger and more elastic, so they wouldn’t snap like bones that get low BMD, because they’re osteoporotic. They are different structurally under the microscope. But, of course you don’t want to take risks, so your points about protection etc., are valid.

Same with muscle. Old muscles have a lot of fat infiltration on both cellular and tissue levels. They look reasonable size, i.e. no sarcopenia, but “fatty” - which functionally and metabolically is suboptimal. Meawhile a CR’d muscle is just strong lean tissue stripped out of all infiltrating fat - healthier and stronger gram for gram. The muscle may look slimmer, but is much stronger.

If one were to go by CR studies in mice and rats, exercise is totally optional if you are on CR, and in fact negative at the very bleeding edge (not really feasible in humans, lol!). For humans, some moderate exercise on CR is quite OK, but in my subjective opinion, not essential as long as you got your CR really dialled in. YMMV.

#6

Generally I think the CR does reduce caloric output by regulating willingness to move, so the idea might be to find a balance for physical inactivity at an appropriate BMI and markers showing CR is going on (like lower body temp, lower body fat), then add in physical activity for improving mitochondrial function in for example the legs (zone 2), with better and more mitochondria that might be transported elsewhere, and add calories on top of it for what is burned… That way the CR doesn’t become too high? (some thought to VO2 max can be made too… but zone 2 is good for it at least some I believe).

Or do you think that for example CR at 1600 kcal without exercise is superior to CR with 1600 kcal + 200 kcal exercise and additional food?

#7

In studies on rats they ran through that exact scenario. Mid level CR 25-30%, you could exercise the animal and add back in those calories lost (but not more!), and the life/healthspan would be equal - but only for light-moderate levels of exercise (so, not Michael Phelps like 10,000 calories and extreme exercise). But at the bleeding edge CR 65-75%, adding ANY exercise plus compensated calories resulted in much inferior outcomes.

There is however one intriguing exception. In a series of experiments Holloszy et al conducted, rats were put in cold water at the bottom of the cage all day (“rats with cold feet”), and those rats were on CR, but could consume more calories to keep warm, and that excess never hurt them even at extreme CR, UNLIKE ecercise. So, if at the bleeding edge of extreme CR, you can not eat more and exercise it off, but you can freeze, and eat more to compensate. The only exception to CALORIES ABOVE ALL.

But getting back to moderate CR, yes, exercise and compensatory calories are fine (like in the example you gave), and might improve appearance if nothing else!

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#8

I never saw a difference with CR and just maintaining a low BF %

Is there a difference?

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#9

Absolutely, totally different. The best way to immediately see these differences, is to look at the extremes. Bodybuilder 4% fat, dies at 26. CR’d rat starving at 4% body fat outlives the entire cohort of 10% body fat rats.

How you get to low body fat makes ALL the difference. With exercise and high calories - FAIL. By consuming fewer calories, poor diet - FAIL. By consuming fewer calories, excellent diet - SUCCESS.

Fundamental differences.

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#11

This doesn’t sound like a problem with exercise but with insufficient calories creating a frail, non robust creature that cannot tolerate normal activity.

I think there is something to CR but it’s hard to find the sweetspot. Our physiology allows for and maybe even operates best on the least necessary calories and protein and other nutrients. I believe that consistently consuming more than the minimum calories and protein (plus a little reserve) creates problems eventually. But consistently too little also creates problems. So, how to balance? Don’t hang out on the edge either way. And watch for visceral (and other ectopic) fat. And be sure to exercise and engage in physical play: strength, endurance, high intensity, power /‘acceleration, hand-eye, anticipation and reaction.

That’s my plan. I hope it’s a good one.

#12

Bryan Johnson is doing it wrong then. He’s really skinny, but does too much exercise?

The idea of putting an inch of cold water on the basement floor and walking around down there all day barefoot so that I can have another spoonful of hamburger? I choose death.

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#13

LOL! The “rats with cold feet”, was just a mode of cryotherapy. The health benefits of low temperature exposure are well established. On the dearly departed Crsociety.org website (RIP), there was a huge 1000+ post thread curated by one of the members, dedicated to exploring this modality of life extension. The case for it is very convincing, with extensive research behind it. The main mechanism is of action is through BAT (Brown Adipose Tissue), and WAT conversion to BAT. Massive observable and measurable benefits vs BS control, antidiabetic, lowering of systemic inflammation, lowering of BP, etc., in many ways mimmicing CR. There are also many studies showing cold exposure as life prolonging in multiple animal species.

The human intervention was ice baths and special ice vests (available on Amazon), keeping ambient temperature low, sleeping in low temp, under only a sheet, cold showers etc. Quite a few people did it on that list, but it seemed miserable to me, so I much prefer CR, but apparently folks claim that you can adapt to it and it becomes OK. I never tried it, brrr.

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#14

I have been doing a CR-light version since 25 years. I love food and a 4-hour food window lets me splurge, with ca 1.4 kilos in my main meal with a kilo of veggies. Later a treat that includes delicious berries, nuts etc. In the evening, for social reasons. Occasionally a big cheat at social events, which may contribute to my BMI being close to 21. I don’t know if this qualiifies as CR and I don’t count calories but I enjoy it greatly.

#15

CR-light is a good term, pretty much what I do. I just don’t eat very much. Two meals a day, TRF to about 6-8 hours, keeping the calories lowish, currently BMI 20-21, avoid overeating, but no longer weigh and measure my food, mostly because from years of experience measuring, I can eyeball ballpark calorie content reasonably well. Strict CR involves counting calories, so I don’t claim to be on CR anymore, though I likely am on like 10% or so, probably.

When I first stopped CR, I didn’t control my diet much, would go to restaurants if I felt like it, but gradually drifted back to low calories, just because it felt better. A strange effect was that over time I lost a lot of interest in food in general, and just don’t feel motivated to explore. I rarely go to restaurants, and only do so for strictly social reasons, and then don’t eat much, unlike back in the day right after quitting CR, where a restaurant meal would be an occasion to feast.

I’m much more focused on quality than quantity, but food occupies a much, much smaller space in my attention. I eat, but otherwise give food no further thought, though I still read diet related studies. Otherwise I have better things to do with my time - but that’s me, and I know food is a great source of joy and pleasure in life for a ton of people, which is fantastic; we’re all different, and that makes the world go around :slight_smile:

#16

I will consider CR later in life. Currently, I have exercise goals involving pull-ups and weights. At some point, perhaps when I’m 80, my goals will probably lessen to daily walks, stretching, and yoga. At that point, I think CR wouldn’t be a burden. My current BMI is 21. Based on my weight in high school, I don’t think I can go below a BMI of 20 and still maintain my current exercise goals. Old people seem to lose weight naturally, almost like their body is making them do what is needed. I think a BMI of 18 for me would get me into a decent CR zone without much effort and while maintaining an appropriate exercise regimen. Yes, it would be starting very late in life, but I think it would still decrease my risk of dying of CVD or cancer, especially if I start the protocol before I get any stents or any diagnoses of cancer.

#17

CR, as described in some of the above posts, is sort of a razor’s edge. Too little may cause problems in the immune system, intolerance to glucose, excessive tiredness, feeling of cold, and excessive emaciation.
Some people tolerate it better than others though. Lower muscle mass is an undesired effect for some, even if the muscles may be leaner. I tend not only to lose mass, but strength as well.
There is probably an optimum, a sweet spot, around a BMI of 20-21 kgm-2, but again that depends on individuals. Bryian Johnson apparently adjusted his CR percentage more and more upwards.

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#18

Getting on CR is really greatly dependent on personality and individual priorities. It’s kind of a Faustian bargain. You get to live longer/healthier, but at a cost, and for some that cost is unacceptable. If food is your great pleasure in life, then living longer with less of that pleasure kind of misses the point. It’s like being given a bag of money, except you’re not allowed to spend it. What’s the point? This is true of quite a few of these interventions. We know that for males in particular, castration is life prolonging. It’s true in animals as much as in people - there are studies showing eunuchs living longer, and anyone who has had pets dogs/cats knows this too, neutering prolongs life and health. Now, unless you’re some kind of monkish ascetic, who doesn’t care about food or sex, who would ever go for it?? Faustian bargain - you get to live longer at the cost of your sex life. Again, bag of money you’re not allowed to spend. For the vast majority it misses the very point of a longer life. Btw., a side effect of CR is lower sex drive - you’re just less interested.

That’s the appeal of substances like rapa - and further on the horizon, the real prize, genetic manipulation. You get to extend your life and health without compromising. CR and such interventions are primitive early attempts at human longevity, and the results are underwhelming giving the extortionate cost, just as early surgery back in the 1800’s was underwhelming. It works, some of the time, but very often at an unacceptable cost.

For now, we have rapa - maybe. We’re doing the best with what we have. CR is a bridge too far for most of us. I’ve done it, but ultimately, I’m throwing the dice with rapa. We’ll see. YMMV.

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#19

I’m not seeing any answers here that support long term use of CR. To be devil’s advocate, I think true long term CR isn’t really possible. You will eventually run out of weight to lose if you’re truly running a calorie deficit.

#20

This is a misunderstanding of how CR works. When you are at a certain weight, f.ex. 150lbs (my weight pre-CR), and drop your calories from, say, 2000/day to 1500/day (you do it gradually, over a period of months, otherwise CR can shorten your life rather than lengthen it - in animal studies, too drastic a sudden cut to calories rather than gradual decrease resulted in the CR animals living shorter, not longer), you will lose weight. You will continue losing weight UNTIL your weight stabilizes. You will no longer lose weight even though you still eat 1500 calories. That’s because your basal metabolic rate changes - so you are in caloric deficit to your OLD BMR, but are no longer in deficit to your ADAPTED BMR, which is lower. How that happens I mentioned before: your body switches from growth to maintenence and efficiency (cutting back on unnecessary tissue), drop in your core temperature (saves calories), drop in NEAT, i.e. unnecessary - non-exercise movement (such as fidgeting, bouncing legs etc.), which can account for as much as 20-30% of caloric expenditure:

Non-Exercise Activity Thermogenesis in Human Energy Homeostasis - Endotext - NCBI Bookshelf(NEAT,two%20individuals%20of%20similar%20size.

At that point you are no longer in caloric deficit to your new BMR and so you are not losing weight. Now, if you increase the severity of CR, you repeat the cycle, you initially lose weight until you stabilize at the new lower level of calories and new adapted BMR and stop losing weight - I think the top extreme is something like 75% CR in rodents, but obviously lower in humans.

So yes, true CR is possible, humans have done it and continue doing it. I myself have dropped weight from 150lbs to about 125lbs and kept it there for some 8 years. And of course we have endless cohorts of animals in studies of CR that maintain that for the entirety of their lives.

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#21

Cronos has already answered. Target of CR is usually about 15-20% less bodyweight than a lean age 20. So when you reach that target, you adjust your calories in such a way that you no more lose weight. Check and adjust, check and adjust. As Cronos says, you will reach a determined setpoint where you will lose no more weight, with a determined phenotype: very slim, slowed metabolism, and so on. You were on a calorie deficit, but only relative to the starting phenotype. Now, with the new CR phenotype, you are no more on a deficit. You reached a new balance or setpoint.