Would you decrease your calorie intake and weight further?

[Matt]

As some of you probably know, I've been on a *CRON* diet since around 2005, but prior to that for 2 years I was removing sugar, sweets, fizzy drinks from my diet, and I was adding more nutritious cereals and fruit to my diet. This resulted in significant weight loss even before I adopted CRON and more carefully tracked my weight and everything else. 

In 2005, my weight dropped to around 104 lbs or a BMI of 16. I was eating approximately 1550 k/cal per day and measured my food intake and calories every day.

I did increase my weight after 6 years of very strict CR, and then a few years later my BMI decreased again to around 17.5 and remained there for some years.

And now in 2019, my BMI is around 18.5 and my calorie intake is between 1500-1600 k/cal per day. BMI has stayed the same for years.

I eat pretty much the same thing every day. I've measured my calorie intake multiple times very carefully to make sure I'm not eating more than than I think I am, and it consistently comes in around 1500-1600 Calories. And there were some days it was much less! 

Has this happened to anyone else? I'm more curious about people who have been on CR for years.

I now seem to be much more resistant to losing weight than when I first started.

On the one hand, I'm aware of research saying that mice on CR that are able to hold onto weight tend to do better. On the other, I'm wondering if I could push CR a bit harder. But with my calorie intake already quite low, that also concerns me. 

 

 

Edited August 20, 2019 by Matt

[Dean Pomerleau]

Matt,

28 minutes ago, Matt said:

Has this happened to anyone else?

What you mean by "this"? Being resistant to (further) weight loss?

I eat many more calories than you (over 3000 kcal/day) but am presumably much more active. My weight has been stable for a long time around 127-129 lbs (BMI of ~19). I too eat the same thing every day. But unlike you, I don't weigh my food anymore, relying on my body weight and the fact that I exercise nearly the exact same amount every day to maintain my degree of (pseudo-)CR.

I'm not interested in going any lower in calories or body weight, given my skepticism about the magnitude of CR longevity benefits in humans and the risks associated with severe CR (i.e. increased fragility). But like you it does seem I'm eating somewhat fewer calories than I used to in order to maintain my weight at the same level of physical activity. I'm not sure whether this apparent increase in efficiency is an effect of CR or a typical result of getting older.

--Dean

[Saul]

On 8/20/2019 at 8:59 AM, Matt said:

I now seem to be much more resistant to losing weight than when I first started.

Hi Matt!

That's definitely true for me.  I began CR in April, 1996.

  --  Saul

[Matt]

@Dean Pomerleau

I meant that there have been times when I've been on a tight budget and I've eaten as little as 1300 k/cal per day (some days) for a week or two but my weight barely changes. 

This is significantly less than the number of calories that would be predicted for me based on calculations of my BMR and activity level.

And as I said, when I first started CR, eating 1550 k/cal per day caused my BMI to drop to 16. But now I'm maintaining a BMI of about 18.5, but I'm eating just over 1500 k/cal per day.

I'm wondering if it's just an age thing or my body composition has changed.

But the question is: Should one try to maintain their BMI and reduce calorie intake over time to prevent any increase in body weight or let the weight creep up with age and not further decrease calories. 

Of course, I still believe CR still works really well, which is why it's tempting to decrease calories further. I wouldn't let myself go below a BMI of 17.5 anyway, so it's not that far from where I am right now. 

That being said, I'm also mindful of the risks of having a low body weight and given that I'm still quite young (35 in Oct), I might be young enough benefit from treatments that are superior to CR and actually reverse damage and effects from aging.

Calorie restriction has become so normal and easy for me to do, it doesn't feel like I'm even trying anymore. And that's not to just gloat to people who say they can't do it... I just wonder if I should be at least a bit uncomfortable or significantly more hungry than I am. In terms of hunger, I guess one way to do that would be to increase activity.   

@Saul Thank you for your feedback. 🙂

 

Edited August 26, 2019 by Matt

[Dean Pomerleau]

Matt,

I think you answered your own question. If you really believe in the "calories, calories, calories" mantra promulgated by hardcore CR folks (like Michael), then dropping calories further would be the way to go, assuming you can still maintain sufficient intake of important nutrients. 

I personally don't subscribe to that camp anymore on two accounts. First, personal experience based on my bloodwork suggests that rather than focusing on absolute calorie intake, running a net calorie deficit to keep oneself slim is sufficient to trigger the "maintenence and repair" mode that is the hallmark of CR, and presumably the source of its beneficial effects.

Second, my reading of the available evidence suggests hardcore CR won't substantially extend human lifespan relative to a healthy, obesity-avoiding diet and lifestyle. I also think the evidence suggests hardcore CR and the resulting very low BMI (less than ~20 but especially less than 18) makes one more fragile, and therefore more susceptible to health challenges that less restricted and therefore more robust individuals could weather successfully, although this would likely be more of a problem for people practicing CR who are much older than you are. For more discussion of the CR fragility hypothesis, see here and here.

So my perspective is that restricting your calories further would likely be counterproductive for your long-term health and longevity.

--Dean

 

[Ron Put]

Dean, I am assuming that you are not running a "net calorie deficit" consistently, since that would result in a continuing loss of mass. At least this is the case for me.

I have read (and believe that I have posted on this forum) studies which support exercise plus caloric restriction. Which makes sense, as exercise builds muscle mass, increases cardio fitness, increases BAT, increases autophagy, etc..

The problem I find trying to balance it is higher protein intake, at about 160% according to Cronometer. My last IGF-1 is just over 180, although the more I read about it, the less I am worried about it (perhaps confirmation bias kicking in).

[Dean Pomerleau]

13 minutes ago, Ron Put said:

Dean, I am assuming that you are not running a "net calorie deficit" consistently, since that would result in a continuing loss of mass. At least this is the case for me.

You are right Ron. What I mean is eating sufficiently few net calories (food - (baseline metabolism + exercise expenditure)) to maintain a relatively low BMI and (hopefully) trigger the health/longevity-promoting CR response.

--Dean

[Matt]

Some numbers to possibly explain why I've been able to maintain a higher body body weight at a lower calorie intake in recent years?

I've read that T4 is usually stable up until older ages, but I've seen trend downwards over several years. When I last got it measured, it was close to the CR group in WUSTL study, but they they were close to 60 years old.

Serum fT4: Reference: 9.8 - 23.1

22.9 (2005) - start of strict CRON

20.2 (2005)

20.8 (2007)

19.2 (2007)

18 (2013)

13.9 (2016) - TSH 1.6

I saw a steady decrease in fT3 from 5.5 to 4.6 but never got it tested in 2016.

I've been keeping a closer track to my calorie intake by measuring everything I eat. Some days are really low, but that's just because I forgot to input the data. I eat the same foods every day  anyway, so it's probably similar to fully tracked days. 

A few days missing as I was unable to forgot to track but some are just due to adjusting sleeping pattern . 

I've not seen any weight loss at all... but I expected as much as I buy the same amount of food every week and I eat the same thing almost every day.

So it seems to be true that I can now maintain a much higher weight at the same calorie intake as I was at when I first started CRON.