Advice needed for restarting CR after unsuccessful attempt.

[Ash]

Hello,

I practiced CR for approximately 2 years.  I am mid 50's, 6'2 height, and currently weigh 155lbs, moderately active (3 - 4 x week) both cardio and calisthenics.  I am also vegan for 9+ years. Initially, upon starting CRON, I went from 168 lbs to about 138 lbs eating 1900 Kcal/day (food measured w/scale, eating 633kCal x 3 meals/day). I used cronometer to ensure I was meeting nutrient numbers to avoid undernutrition. The first year was easy and where I lost the majority of weight, no adverse issues. Entering into the second quarter of the second year, I started having strange psychological food cravings and feeling the need to binge eat at odd times of the day, i.e., one example, probably a 3,000kCal meal of dates and pretzels (weird food combinations, I know).  I attempted different techniques to combat the sensations of my brain telling me to eat something ridiculous hand over fist and failed, i.e., eating a small meal of cruciferous veggies to feel 'full' about an hour prior to the last meal of the day.  I tried to maintain CR over the next two quarters of the second year and gradually couldn't maintain it.   I abandoned CR at the end of the second year but maintained veganism easily, but probably started freely eating ~2500 to 2900 kCal per day (estimate) and have gained about 15 lbs of bodyweight, but am still 'fit' and lean.  I finally felt 'happy', obviously eating to satiation with no amount or calorie constraints. I have researched CRON fairly extensively, and understand the (potential) benefits and would like to try to re-engage with it in earnest, but this time succeed.  Any suggestions?  Best regards to you, Ash.

[Dean Pomerleau]

Hi Ash and welcome to the CR Forum!

1900 kcal/day for someone who is 6'2" and moderately active is pretty serious CR. At 138lbs you were at a BMI of 17.7, which is getting into the territory where the body starts to object to a continuing deficit. Food cravings and binging are not unusual when someone gets to that point. 

Did you try backing off to an intermediate calorie level between 1900 and your current 2500-2900 kcal/day? Your weight might have stabilized around 140 on around 2200 kcal/day. 

Given some of doubt about the life extension efficacy of human CR triggered by the disappointing results of the primate CR experiments, some of us long-term CR practitioners have backed off our level of CR, targeting a BMI of 18-20, which isn't far from where you are now. If you are eating a health diet, exercising regularly and maintaining a BMI slightly under 20, I personally don't think you (or I) have much to gain in terms of healthspan or lifespan by dropping calories substantially further. As you've discovered, it makes life more pleasant too.

This is a bit off topic, but given my pessimism about better life extension methods becoming available anytime soon (i.e. the next couple decades), and my doubts about the viability of the human enterprise during the latter half of the 21st century given our current trajectory, my enthusiasm for maximum my chance of reaching longevity "escape velocity" via hardcore CR has been tempered substantially.

--Dean

[Ash]

Hi Dean, thanks for your response!

I have re-engaged CRON for a few days now and feel better overall than just eating ad.lib.  I think your suggestion may be a good way to proceed.  Perhaps not 1900 at the start, but 2000/2100 for a period of time, then slowly attempt to decrease.  

Question:  Is there an accurate way to estimate % of caloric restriction?  I recall Walford advocating for 1800 kCal/day for potentially highest level of theoretical longevity increase; however, that is too restrictive for me personally.  A few years ago I used a website (https://www.scientificpsychic.com/health/cron1.htm) to enter my body metrics, etc., and it output an estimated % caloric restriction; according to that source, 1900 was around 23%-25% CR.  I am not certain if the output was truly accurate.

Also, is calorie restriction linked to how many calories an individual uses; for example, if I jog four times a week, I'm burning more calories than someone who is more sedentary, but is the calorie restriction % irrespective of activity level?   If we possess similar body metrics, would the % CR be the same for both of us regardless of the fact that I am using more over a period of time?

On a different note, were there issues with the primate CR study or its design?  If I recall correctly, the health-span of the CR+ primates increased significantly as compared with controls.  I can't recall if they saw increased longevity...?

Best regards to you, 

-Ash

[Dean Pomerleau]

1 hour ago, Ash said:

Is there an accurate way to estimate % of caloric restriction? 

No.

1 hour ago, Ash said:

Also, is calorie restriction linked to how many calories an individual uses; for example, if I jog four times a week, I'm burning more calories than someone who is more sedentary, but is the calorie restriction % irrespective of activity level?   If we possess similar body metrics, would the % CR be the same for both of us regardless of the fact that I am using more over a period of time?

We've had endless discussion of this topic, and never reached a consensus. Some very respected people like Michael Rae believe it is the calories that count. He advocates doing just enough exercise to maintain cardiovascular and bone health, and otherwise cut calories to the bone. I'm personally of the opinion that it is the net calorie deficit (i.e. calories in vs calories out) that counts. That is, humans can probably get the same maximum lifespan benefits of CR (maybe = 1-4 years) by either cuttings calories to the bone and performing minimal exercise or alternatively, eating more than the bare minimum and exercising to maintain the same net calorie deficit. But it is pretty clear that exercise alone won't extend your "max lifespan" - see this post from @TomBAvoider for a good discussion of this point:

 

1 hour ago, Ash said:

On a different note, were there issues with the primate CR study or its design?  If I recall correctly, the health-span of the CR+ primates increased significantly as compared with controls.  I can't recall if they saw increased longevity...?

Yes, there were plenty of issues with the design. See this thread and it's links for discussions of the primate CR studies and other evidence for and against the efficacy of CR in humans:

 

The bottom line seemed to be that by eating less of the crappy diet used in the Wisconsin study, the CR monkeys saw some lifespan benefits relative to the obese, ad lib-fed control monkeys. But compared with control monkeys fed a good diet and restricted enough to avoid obesity in the NIH study, the CR monkeys didn't live any longer.

[Dean Pomerleau]

1 hour ago, Ash said:

Is there an accurate way to estimate % of caloric restriction? 

No.

1 hour ago, Ash said:

Also, is calorie restriction linked to how many calories an individual uses; for example, if I jog four times a week, I'm burning more calories than someone who is more sedentary, but is the calorie restriction % irrespective of activity level?   If we possess similar body metrics, would the % CR be the same for both of us regardless of the fact that I am using more over a period of time?

We've had endless discussion of this topic, and never reached a consensus. Some very respected people like Michael Rae believe it is the calories that count. He advocates doing just enough exercise to maintain cardiovascular and bone health, and otherwise cut calories to the bone. I'm personally of the opinion that it is the net calorie deficit (i.e. calories in vs calories out) that counts. That is, humans can probably get the same maximum lifespan benefits of CR (maybe = 1-4 years) by either cuttings calories to the bone and performing minimal exercise or alternatively, eating more than the bare minimum and exercising to maintain the same net calorie deficit. But it is pretty clear that exercise alone won't extend your "max lifespan" - see this post from @TomBAvoider for a good discussion of this point:

 

1 hour ago, Ash said:

On a different note, were there issues with the primate CR study or its design?  If I recall correctly, the health-span of the CR+ primates increased significantly as compared with controls.  I can't recall if they saw increased longevity...?

Yes, there were plenty of issues with the design. See this thread and it's links for discussions of the primate CR studies and other evidence for and against the efficacy of CR in humans:

 

The bottom line seemed to be that by eating less of the crappy diet used in the Wisconsin study, the CR monkeys saw some lifespan benefits relative to the obese, ad lib-fed control monkeys. But compared with control monkeys fed a good diet and restricted enough to avoid obesity in the NIH study, the CR monkeys didn't live any longer.

[Ash]

Wow Dean thanks for having the patience to point me in the right direction!  I have a lot of studying to do for sure.

Best regards, 

-Ash

[Saul]

Hi Ash!

Dean's opinions about the monkey studies are just that:  Dean's opinions.  I wouldn't necessarily take them seriously.  (Anyway, Dean's opinions work for Dean).

  --  Saul