13 replies to this topic

[Alizee]

Does anyone know what happens to someone who excercises a lot (burns off 500 calories a day at least) and does CRON at around 1200 calories?

[DR01D]

It's simple math. That person will starve to death.

My base calories are 1800 per day. However on days that I lift weights I add an additional 500 calories. 400 calories to cover an hour of exercise and 100 calories to build muscle. This plan works. I build muscle and gain strength at a steady, reliable pace.

Natural bodybuilders can only build 5 pounds +/- of muscle per year. It only takes a small, daily surplus to accomplish that. It doesn't take that much protein either. Roughly .5 grams per pound of bodyweight per day works fine. Any more is a waste.

The Truth on How Much Protein You Really Need Per Day to Build Muscle

[Alizee]

thanks,

oh I don't want to make a new thread, but what does people think the STAPLE food item for cron. like something i could use a lot and not go wrong.

is it kale?

[sthira]

Fruits, vegetables, legumes, nuts, olive oil, green tea.

[DR01D]

I eat piles of raw vegetables to stay full. Without that I don't think I could make it. Otherwise fruits, nuts and a small amount of protein with each meal.

Cut out processed carbs and you'll reduce your hunger.

But you have to eat enough calories to support a physically active life. No more, no less.

[xEva]

It's simple math. That person will starve to death.

My base calories are 1800 per day. However on days that I lift weights I add an additional 500 calories.

I beg to differ. Of course what you say 'makes sense' and appears logical and all, but..

Recently, within a past month or two, I remember seeing here a paper about 30-40% CR'd mice or rats, and in it, for the first time, their physical activity was measured by an implanted electronic device. It turned out that CR'd rodents were ~50% more physically active than the ad lib group. I even remember the numbers, it was 19 'units of activity' for CR group and 13 for the control.

I found that paper fascinating. Why would a CR'd animal be more physically active --and by such a large margin-- than a well-fed one?

The study was the first to measure physical activity in this way. I'd like to read this paper again, if I can find it. If anyone remembers this paper --it's here somewhere-- please post

It contains an important clue to the old question of what is a calorie. Experienced fasters report that they feel more energized and their fasts proceed easier when they continue their exercise routines during a fast. Some run and some pump iron and some do both (even though most cut their usual intensity by 30-50%) . These are real fasts I'm talking about, 2-3 and more weeks, not days.

The underlying theory is that physical activity activates the Cori cycle (lactic acid produced in muscles is changed to glucose in the liver to feed the brain). And subjectively, a good workout makes you feel as if you've eaten; i.e. it rises your energy level, mood, concentration, etc. (all this during a complete water-only fast).

The other theory is that physical activity upregulates mitochondrial metabolism, which allows one to make a better use of a calorie. In theory, the number of ATP produced from one glucose molecule ranges from 1 to 38. This alone should put an end to 'a calorie is a calorie' idea, because, depending on how well your mitocondria function, you can produce a wide range of ATP from the same amount of substrate.

In summary, physical activity, instead of demanding more calories, can significantly lessen the caloric requirements, and the recent rodent study that measured their activity offers the first clue to this.

Edited by xEva, 03 January 2013 - 09:16 PM.

[xEva]

PS

I forgot to stress that, in the short run, introduction of a new physical activity will of course rise the demand for calories. It is after a period of adaptation --however long that takes-- that the demand for calories goes down as it is essentially matched by improvements in metabolic efficiency.

[DR01D]

It turned out that CR'd rodents were ~50% more physically active than the ad lib group. I even remember the numbers, it was 19 'units of activity' for CR group and 13 for the control.

The CR'd rodents have less mass and so they burned less energy per unit of activity. Maybe CR increases efficiency but it's hard for me to believe that a body under CR becomes 50% more efficient.

[xEva]

I googled ATP production and the latest is about 30 max per glucose and 42 max per fatty acid in mitochondria. As opposed to 2 ATPs per glucose via glycolysis. That's the theoretical max => The range of ATP production per the same amount of substrate (= 'calories in') is huge.

When we adapt to fasting, the first phase of which takes about a week, the metabolic efficiency goes up. This manifests in sudden drop in daily weight loss, on one hand, and development of a marked hunger for O2, on the other. IMO the O2 hunger is the sure sign of a switch to mitochondrial metabolism.

I don't know how much the efficiency actually goes up on a fast, only that it does go up. Which explains why some people manage on a much smaller amount of calories after a fast (discussed in a neighboring thread ~"my experience after a year of CR").

IMO the efficiency can exceed 50% improvement. How much exactly depends on the initial conditions, which, for people who never fasted and are adapted to a western type diet, is not much.

The question about CR'd mice: why were they 50% more active than control? Why would not they follow MR advice and conserve their energy instead? The answer is, they did not know that they were supposed to conserve their energy lol. They did what was natural to them, what made them feel better, which in CR'd conditions means: feeling less starved for energy. The mice showed that increased physical activity leads to improved metabolic efficiency. Instead of robbing them of energy, movement gave it to them.

[xEva]

I still did not find the article that peaked my interest in this -- I saw it linked from Lngecity sometime in the middle of Dec -- please, if you remember it, give us a link-- but I found this: SirT1 Regulates Energy Metabolism and Response to Caloric Restriction in Mice. Please take a look at this graph:

Please disregard the graph below (B), is of messed up SirT1-null mice. The graph above (A) shows activity of normal CR and ad-lib mice. The units of activity are different here from the other article I saw, but please note that at its height, after 25-29 weeks after start of CR, the activity is measured at ~45000 units for CR mice vs. ~20000 units for control ("animals were 5–7 months old at the beginning of CR").

Then there was an article as of summer of 2012, about fruit flies, who too showed markedly increased activity on CR (again implicating SirT).

Since no-one is compelling these animals to move while they are calorie-restricted, I believe they move in response to some 'inner need'. Personally, I too become far more active when I fast, because of what feels like a physiological need. The subjective feeling after a jog or shoveling snow (my favorite exercise in winter) is as if I had a meal. I.e. movement gives energy during a fast.

[mikeinnaples]

The inner need of an animal is easy to explain. Mice for example, will become more active with they are restricted because they will begin to attempt to forage. This is instinct, completely natural, and the result of evolution. I assume this would affect people as well on a base level.

Edited by mikeinnaples, 31 January 2013 - 02:24 PM.

[mikeinnaples]

Regarding the original poster, I have to agree that you would starve with those numbers. Personally, I have always had a problem reconciling calorie restriction with calorie deficit obtained via exercise. I will use my CRON from yesterday as an example (going to round a bit). Yesterday I consumed 2100 calories. It was a lift + distance run day for me at my workout and my activity estimated by CRON burnt 800 of those. This gives me only a 1300 calorie net and believe me when I say I could feel it this morning.

Logically, one would think that my 1300 calorie net yesterday is on par with a CR practitioner, but physiologically speaking, it apparently isn't.

[xEva]

The inner need of an animal is easy to explain. Mice for example, will become more active with they are restricted because they will begin to attempt to forage. This is instinct, completely natural, and the result of evolution. I assume this would affect people as well on a base level.

Yes, this is a very reasonable explanation and it has been obstructing the view of the underlying reality. We assume that the dumb little things forage in a futile hope of finding something to eat. This does not explain the very pronounced drive to move experienced by a faster like myself at the onset of fasting.

And maybe this does not apply to you after all. What I do is different from a form of sustained CR: I stop eating altogether. From the evolutionary point of view, increase in physical activity in a starving animal makes perfect sense: an active animal is more likely to eat in the future than the one lying around conserving its energy. On the other hand, if food is available, albeit in much smaller quantity, then it makes more sense to lie around and not move much -? ***

The underlying reality obscured by your reasonable explanation is that certain pathways evolved to work together, feeding off each other and requiring each other for their proper work. I do not pretend to know what those pathways are and how they interact. I can only share my experience and speculate that movement and cold somehow work together making fasting an easy experience. Much easier than when you lie around in a warm room. Which brings to question the whole calorie paradigm and underscores how little we still know about the metabolism.

***PS
it has been pretty much established that 40% restricted rodents actually fast in between feedings. And by this is meant that they go into the ketosis of starvation, a metabolic state similar to what a human achieves after a week-long fast. So, all these headlines about the benefits of CR in rodents, from life extension to longer telomeres, etc., are not applicable directly to humans (as the recently finished primate study confirmed).

The study above that shows increase in activity applies to 40% restricted (==fasting) rodents. CR, as it is practiced by an average person here, is metabolically very different. My guess is that in order to match what humans do, those mice would need to be fed every 3h, at least, bit by bit, to prevent them from going into ketosis and unleashing the epigenetic changes that come with it. I wonder if anyone saw such studies. i.e. when mice were fed every 3h yet still were calorically restricted.

Edited by xEva, 31 January 2013 - 09:02 PM.

[mikeinnaples]

From the evolutionary point of view, increase in physical activity in a starving animal makes perfect sense: an active animal is more likely to eat in the future than the one lying around conserving its energy. On the other hand, if food is available, albeit in much smaller quantity, then it makes more sense to lie around and not move much -? ***

It would make sense providing the subject is capable of 'reason' like a person. I am not so sure that applies to lab rats though.... well except for maybe The Brain (but definitely not Pinky).