Lex's Journal

[lex_rooker]

Hi Sully,
I’ve tried bison fat and it is very good.  It’s just that I’m in a comfortable routine where I don’t have to think much about diet and eating.  I call in my monthly order to Slankers and then can spend the rest of my time doing other things that interest me.  I seldom give a thought to food.  I have a lot going with pemmican & jerky demos, community volunteer projects, repairing and restoring antique clocks and a host of other things.  Seems like I’ve always got someone over working on one project or another – either mine or theirs.

Ioanna,
Hope you are doing well.   I’ve found that rendered fat works well for me – at least it has for the past year or so.  Much more convenient to store and use than raw fat which must be kept frozen.  I can render a year’s worth in an afternoon and store it in 5 gallon buckets which hold about 35 - 40 lbs.  At 100g per day a 5 gal bucket lasts about 5 months.  If I weren’t giving so much of it away, 100 lbs (after rendering) would easily cover my personal needs for a year.  What with pemmican demos and samples I use almost 3 times that much each year.

I’m happy with my lab results and see no need to change what I’m doing for the foreseeable future. I’ll continue to eat the way most people feed their pets.  It’s easy and I feel great.  I spend a total of 30 minutes or less a day preparing and eating my food.  Cost is also reasonable at less than $10 USD per day.

Lex

[alphagruis]

No problems with kidney stones since the last bout in January or early February.  I started with two stones and both are still lurking just waiting for a chance to bring great misery at the most inopportune time.  One stone has passed into the bladder and it is still there.  The other stone is still up in the kidney area.  Neither seem to have changed in size as best as can be told from the x-rays though we would need a CT scan to get an accurate picture and I’ve decided not to bother unless or until they start to move again.  Just not excited about exposing myself to unnecessary radiation.

When I had my kidney stones problem ordinary X-rays invariably showed a clear-cut increase in stone size over a period of 6 months. So your data are very encouraging and it seems unlikely that your diet has a responsibility or adverse effect in this respect. If I were in your shoes I wouldn't bother too and avoid as much as possible further X-rays of the stones. Ultrasound imaging might be an alternative harmless technique to keep an eye on them. Mine were eventually easily visible and followed in this way by a skilled radiologist. 

What is also very amazing is that your blood lipid profile is very similar to mine (HDL 65, LDL 110, Total cholesterol 180) although I eat markedly less fat of animal origin and a substantial part of plant foods.

Thanks for sharing so openly you experience.     

[Savage]

Good to have you back Lex.

[lex_rooker]

Alphagruis,
The stones in my x-rays are rather fuzzy (at least to my eyes) so it’s difficult to judge size.  My doctor isn’t overly excited about them but then he’s 75 years old and doesn’t get excited about much of anything.  The fact that the stones can be seen in an x-rays shows that there’s definitely calcium involved.  Other than that I don’t have much to report about them.

Savage,
Never left, just very busy with other things.  Since I retired I seem to be going full tilt from sun up to sun down.  I’ve been asked to come back to work at my old job and they’ve offered a very attractive wage, but I’m so busy and having so much fun that I’ve turned them down.

I do check into the forum once in a while but not everyday.  I do answer PM’s promptly as I’m notified by e-mail when I get one.

Lex

[PaleoPhil]

Great to hear that you're still doing well, Lex. Some of the more vocal carb proponents were starting to use your absence as an excuse to imply that you might not be, but my guess was it had more to do with your busy-ness and I could see by your profile that you were still sometimes reading the forum.

Have you managed to stay well hydrated? That's something that I think I still need a little work on, but I don't tend to get thirsty so I tend to forget to drink as much water as I would need to get my SG to good levels. I wonder if that would also help a bit with my continued constipation. How long did your constipation last after you went carnivore and are you thirst-deficient like I seem to be (and was before I went raw carnivore)? Raw carnivory at first appeared to exacerbate my thirst deficiency, but it seems like my thirst for and enjoyment of water is gradually increasing--especially when I haven't eaten much plant foods (I've been experimenting with greens, local berries and other plant foods recently) for a while.

....  I’ve found that rendered fat works well for me – at least it has for the past year or so.  Much more convenient to store and use than raw fat which must be kept frozen. ... I can render a year’s worth in an afternoon and store it in 5 gallon buckets which hold about 35 - 40 lbs.  At 100g per day a 5 gal bucket lasts about 5 months.

Actually, I've found that suet lasts more than 5 months just stuck in paper bags on a shelf. There is a concern about oxidation, however, so I usually buy in small enough quantities (at $1.70 - $1.90 /lb.) so that I don't have to store it for very long, but I stuck some on a higher shelf and didn't eat it to see how long it would last. It seems to last forever. Interestingly, suet tastes better to me when it has been aired out for more than a few days and it tastes worst if it's been in loose plastic that was not vacuum-packed, has some moisture in it, and is stored this way in the fridge for more than a day or two.

What do you think of KGH's and Alphagruis' argument to eat a small amount of carbs so the body doesn't have to convert protein into carbs in a less efficient manner?

[lex_rooker]

Hi Phil,
Yup, very busy with doing things I enjoy.  For me, eating the way I do is a means to having the energy and health to do what I want and not the end in itself.  My food intake is so simplified that there is very little that I can add to what I’ve already said.  I get my annual checkup and the numbers continue to support this simple lifestyle as well.

I do drink considerably more water now than in the past.  I try to keep my intake up in the 3 liter/day level.  I have the same problem as you in that I’m not thirsty most of the time, but the thought of kidney stones mucking about in my urinary tract is plenty of incentive to keep me at the water trough a bit longer.

The last suet I purchased was about $1.30/lb which I thought was a pretty good deal.  Rendering it just makes it very easy to store and there is nothing to cut or chop when I want some.  Just scoop, mix and eat.

I’ve pretty much come to the conclusion that our bodies will convert a good bit of all the protein we eat into glucose whether we eat carbs or not.  There are several entries in my journal showing my BG measurements and the associated calcs that seem to support this.  If others have actual experimental data that conflicts with the data I have, I’d be interested to see it.  I spent a good bit of effort in setting up experiments where I varied protein levels with and without added carbs while tracking BG every ½ hour.  I also ran each protocol for a full week and then compared the BG curves.  All seemed to indicate that between 55 and 60 percent of all protein eaten ultimately turned to glucose.  When carbs were added the BG peaks just went higher than with protein alone, and the rise was consistent with what would be expected for the amount of carbs eaten.  The rise in BG caused by added carbs was also much shorter duration and superimposed over the much longer broader rise in BG caused by protein.

To be honest, I’ve pretty much come not to care much about it anymore.  My body does whatever it does with what I eat, and as long as I continue to feel great, if it wants to create glucose out of protein (or not) it’s OK with me.  I trust that my body will do the right thing regardless of what nonsense I’ve chosen to believe or disbelieve.  From what I’ve been able to glean from my most careful observations is that my body really doesn’t care what I think.   It’s what I do (or don’t do) that causes it so much trouble….

Lex

[alphagruis]

I’ve pretty much come to the conclusion that our bodies will convert a good bit of all the protein we eat into glucose whether we eat carbs or not.  There are several entries in my journal showing my BG measurements and the associated calcs that seem to support this.  If others have actual experimental data that conflicts with the data I have, I’d be interested to see it.  

 According to well known standard biochemistry, amino acids cannot be stored or excreted. So any dietary excess that is not used to synthetize our own proteins and enzymes is actually converted into metabolic precursors (such as pyruvate, oxaloacetate or alpha-cetoglutarate) of glucose, fatty acids and cetonic bodies . If there is no carbs intake from diet, part of these precursors ends up in the form of glucose otherwise one might expect that the excess of amino acids rather ends up in the form of fatty acids. At any rate in all cases the amino acids must initially be deaminated and the nitrogen excreted in the form of urea. In terms of nitrogen waste excretion this means that only the total protein excess intake matters independent of carbs intake.

So the point re a minimal carbs intake is that it permits in principle to reduce the excess of protein intake and thus nitrogen waste excretion on the one hand and on the other hand has (again in principle) a better energetic efficiency because endogenic synthesis of glucose ( the path from pyruvate to glucose in gluconeogenesis) needs a priori extra energy in the form of ATP's and thus production of extra reactive oxygen species. Yet maybe glucose can be essentially obtained from glycerol in fats or merely from pyruvate end metabolite in glycolysis and close a cycle. Moreover some of us have trouble with carbs digestion and maybe carbs digestion needs more energy than protein digestion and this might well offset the above mentioned drawbacks.

So we can hardly conclude now and certainly have to rely on more experiments such as yours, Lex.        

[lex_rooker]

alphargruis,
I suppose that the key is in your wording like “one might expect” and “in principal”.  Truth be told I don’t know and I don’t know anyone who does know, and for all practical purposes it doesn’t matter much in my daily life.

I have no evidence that there is some health penalty paid when protein is converted to glucose.  Neither do I have any evidence that there is some health advantage gained (or penalty paid) by eating a few carbs.  The body has several metabolic paths that it uses depending on the conditions it is facing.  How do we know that one is better than another from a practical daily living standpoint?  And, why on earth would I make dietary decisions based on trying to control something that I admittedly know very little about (from the standpoint that I don’t know if one metabolic pathway is truly better than another), and I can’t measure anyway.

What I can measure is in my lab results and each year they seem to get better.  On top of that I feel great.  Whatever metabolic pathway my body is using seems to be working well for me in “reality”, so in “principal” I see no reason to change.

Lex

[Paleo Donk]

Hello Lex,

I must admit that I love your attitude towards diet and wish I had more simple non-convoluted thoughts you seem to possess and am most happy about your statement about spending your time doing things you love. This is no doubt I believe a key to your health and vitality.

Unfortunately for me, I am obsessed over smaller details and don't really feel settled at all with my decisions with regards to dieting. One of the more troubling issues I have come across while on this diet is at what level protein begins to become toxic (or at least sub-optimal) to the body. There is a great thread on the dirty carnivore forum about health problems found in the Inuit.

http://forum.dirtycarnivore.com/index.php/topic,304.0.html

Since the Inuit did appear to possibly suffer from some bone health issues, one connection can be made is regards to the protein level in their diet as higher levels of protein intake have, as even studied in some controlled trials have shown to decrease calcium balance.

Mean calcium balance decreased from 8mg to -62mg per day when the protein intake was increased; the difference was highly significant (P <0.001).

The diets differed in protein content from 48g to 142g per day. I have uncovered quite a few more studies like this one that show similar results. It is no doubt that protein becomes acutely toxic at some level - I believe beginning in the 250-300g per day as this is where nitrogen excretion capabilities of the body seem to be maximized.

There is no way to tell the protein intakes of these pre-contact eskimos but it does really make me wonder if some of them were consuming protein well in excess. For me, excess protein(as the case where significant carbohydrate is in the diet) is the level just above where nitrogen balance takes place, which from studies is remarkably low - perhaps in the 30-50g per day range. As Alphagruis likes to point out, humans do not have the enzyme uricase as do other mammals to help reuse nitrogen end products.

Clearly there is much to the story and I will be experimenting with low-protein diets or intermittent protein consumption in the future to test this. Perhaps humankind had to turn to more plant sources and higher protein once the megafauna died out and the earth warmed.

[alphagruis]

Lex

I agree with your comment.

Since Phil mentioned it I recalled my point in your journal but it was not initially (in an other thread) addressed to you nor was it  intended to dissuade any ZC from staying on his diet. It was initially a response to some outrageous claims of other ZCs.

I appreciate very much you approach and journal and my personal present guess is that there are probably very different (in terms of carbs intake or otherwise) "healthy" diets.

Paleo Donk

It would be of interest to find out whether or not the minimum protein requirement is indeed increased in ZC as compared to a diet that provides the minimum glucose required directly in diet.      

[PaleoPhil]

My food intake is so simplified that there is very little that I can add to what I’ve already said.  I get my annual checkup and the numbers continue to support this simple lifestyle as well.

Unfortunately, my improvements have still not been as comprehensive as yours. I still have daily constipation (it improved for a couple weeks on raw ZC and then gradually relapsed, though without the other IBS-type problems I used to get), mild dehydration, mild residual toe cramps that are held at bay with low daily doses of potassium, and what most people consider underweight (currently 133 lbs at 5’11”, a narrow frame and what people tell me is an “emaciated” appearance except for a small amount of belly flab—aka “skinny fat”—however, it is about the weight that I was at in my 20s and 30s). I suspect that increasing my intake of organs and water to levels closer to yours might help some.

I try to keep my intake up in the 3 liter/day level.

I find that my bladder gets painfully bloated before I reach that point and I have to interrupt work and home life frequently with urgent runs to the bathroom. Does the bladder eventually expand to handle this intake or did you have no problem with it from the start?

I’ve pretty much come to the conclusion that our bodies will convert a good bit of all the protein we eat into glucose whether we eat carbs or not. ....

Yes, KGH, Alphagruis and the others acknowledge that, but they claim that the conversion is inefficient and that this is somehow bad.

This question seems unresolved, so I searched KGH’s blog and here is my paraphrasing of his reasons I found for eating around 50g of carbs/day, if you or anyone else has time to look at them:

KGH’s reasons for including at least 5% calories as carbs in the diet that I’ve found:
1.   The body uses 50 g/day carbs (about 10% of total calories) regardless of what you eat
2.   Kwasneiwski’s Optimal Diet recommends a minimum of 5% carbs (and 10% protein) because “you need the glucose anyway so why not eat it straight away” to minimize the “metabolic work” your body needs to do (making your body convert protein to carbs is less efficient, and therefore apparently more metabolically taxing than eating carbs)?
3.   Even Dr. Bernstein recommends 30g carbs/day for diabetics (in a “6-12-12” plan representing the number of carbs eaten at each meal). [Note: However, according to a secondary source, Dr. Bernstein doesn’t claim that any carbs are needed, but just includes them to err on the side of caution.]
4.   Carbs are “the phylogenetically oldest fuel”
5.   “there is no reason to think there is any benefit to eating less than 10%” of total calories as carbs and “there is no advantage to purposely converting your extra protein to glucose”
6.   The excess protein you eat is either inefficiently converted to carbs or is converted into body fat, so eat carbs to provide a safety margin that avoids these two issues
7.   “all protein does not get converted to glucose” (so some apparently gets converted into fat and/or excreted)
8.   People whose BG “levels are still in the 100s after meals and between meals, and not just in the AM … may have some IR going on.” [Note: however, Lex’s BG levels dropped when he increased his % fat intake, if I understand correctly.]
9.   “Paleolithic man had a varied diet so modern man should be able to as well.“ [However, this sounds close to “food re-enactment.” As he has argued in the past, just because Paleo man ate something doesn’t make it optimally healthy.]
10.   Alphagruis adds: avoiding nitrogen waste excretion from converting protein into glucose, which he presumably believes has a potentially deleterious health effect

So it looks like KGH’s argument for eating 50 g/day of carbs boils down to that it reduces the metabolic work your body does so it can instead do more tissue repair and Alphagruis adds that nitrogen waste excretion is reduced. The question is, how do we know that either of these things have benefits in the real world? Based on KGH’s points, it sounds like we should expect that most people will have improved muscle development by including this level of carbs, with the exception being people with IR who may not respond well to carb intake. Based on Alphagruis’ point, it sounds like we should expect increased strain on the kidneys by not including some carbs in the diet and we should look for azotemia (abnormally high levels of nitrogen-containing compounds) and symptoms like:

> Decreased or absent urine output (oliguria or anuria).
> Fatigue
> Asterixis
> Decreased alertness
> Confusion
> Pale skin color
> Tachycardia (rapid pulse)
> Dry mouth (xerostomia)
> Thirst, swelling (edema, anasarca)
> Orthostatic blood pressure (rises or falls, significantly depending on position)
> Uremic frost

Source: http://en.wikipedia.org/wiki/Azotemia

Like Lex, I put more stock in real-world experience than in potential textbook problems from converting proteins into carbs, but my health is not yet as optimized as his, so I'm still somewhat interested in where this question might lead.

[Michael]

Yup, very busy with doing things I enjoy.  For me, eating the way I do is a means to having the energy and health to do what I want and not the end in itself.....To be honest, I’ve pretty much come not to care much about it anymore....I trust that my body will do the right thing regardless of what nonsense I’ve chosen to believe or disbelieve.

That's wonderful to hear Lex!  These are profound statements that many of us should perhaps take to heart - myself included.  I suspect it hasn't always been that way for you considering the long, meandering dietary journey you've taken to get where you are now (as have many of us here) and I wonder if this new meditative state of contentment is a reflection of the state of health you have now attained after much hard work and dedication?

[Hanna]

Yet maybe glucose can be essentially obtained from glycerol in fats or merely from pyruvate end metabolite in glycolysis and close a cycle.       

That sounds interesting. Could you maybe explain this in more detail? So glycerol can be converted in glucose, but only under certain circumstances?

[Hanna]

It would be of interest to find out whether or not the minimum protein requirement is indeed increased in ZC as compared to a diet that provides the minimum glucose required directly in diet.      

After my dentist had discovered the hardened caries in my mouth, another dentist advised me to avoid eating sugar. So I made an experiment and tried to avoid eating fruit. The result was that I began to feel dizzy and that I lacked energy. Furthermore, I really had to force myself NOT to eat fruit because the fruits smelled awesome, even when distant. So I began to eat fruit again without restraining myself anymore and the dizziness problems disappeared. Later i understood that it was not possible to eat much protein with my rawvegan diet. Therefore, no protein was left that could have been converted into glucose.

[Michael]

Nice summarisation Phil. 

Thank you for the explanation alphagruis.

I feel these are issues of extreme importance.  Science, it appears, does not yet provide conclusive answers.

Do I understand you correctly, alphagruis, that the main benefit to attaining a minimal level of carbohydrate consumption is largely because it's a more efficient energetic conversion?  Excess nitrogen waste is an issue with converting protein to glucose but ONLY when there exists an excess level of protein consumed relevant to the bodies needs? 

Yet maybe glucose can be essentially obtained from glycerol in fats or merely from pyruvate end metabolite in glycolysis and close a cycle.

As Hanna also just mentioned, could you elaborate further on the potential and circumstances under which glycerol is converted to glucose?  Are you supposing that this process could essentially eradicate the requirement for the alleged minimal levels of dietary carbohydrate?

As a member whose opinion is greatly respected by myself and others on this forum - What are you own personal conclusions/suppositions based on all of evidence at this point alphagruis?

Without wishing to engage in 'paleo re-enactment' - If one supposes a figure of 50-100g of dietary carbohydrate (as has been mentioned) is required where do you suppose these were obtained in the pre-cooking paleolithic era?

[King Salmon]

Wow Phil.I didn't know you were that thin.Lex has said in previous posts,that increasing fat intake will increase weight.Have you tried that?


I'd also be willing to bet that a lot of us here were "meat deprived" for a long time prior to RPD.So,we probably could live on meat alone for quite a long time with great benefits.However,after 10-20 years of meat only?Who knows?Let's ask Lex when he turns 70-80

[PaleoPhil]

Wow Phil.I didn't know you were that thin.Lex has said in previous posts,that increasing fat intake will increase weight.Have you tried that?

....

Yes, though I don't measure and I find fats very satiating, so it could be I'm not eating as much of it as I should. It seems like I have less appetite for fat lately, so I should probably start measuring out portions again.

There's something to be said for results in the here-and-now too as versus future potential results. If I feel better from raw meat and fat and worse when I include small amounts of fruit, honey or tubers, should I bother to include the latter based on some hypothetical future result? I think Lex and Katelyn have a good point that it doesn't make much sense. On the other hand, it is true that some people didn't notice problems until years down the road, so I take that into consideration as well. I found a base of food that I do well on and I'm experimenting and learning to see if there's any other potentially beneficial foods I can handle well.

[lex_rooker]

Paleo D
I suppose a good bit of my attitude comes from age.  Over the years I’ve discovered that I’m going to get old no matter what I eat or how much (or what kind of) exercise I do.  Seems to be some built in biological thing.  Eating the way I do has also contributed considerably to how good I feel most of the time. I no longer feel sluggish, the emotional highs and lows have leveled out, and the horrible migraine headaches I suffered with for 40 years have gone completely.  Can’t remember the last time I had one.

Not sure what the consequences are of a negative calcium balance.  What does that mean to my overall real world health.  I’ve had a DEXA scan and passed with flying colors.  Bone density has also increased in my jaw enough to be easily seen in dental x-rays.  Blood levels of calcium are smack dab in the middle of the normal range.  If that is the result of a negative calcium balance from over consuming protein in the absence of carbs then apparently that is something I want to continue to do.  There might be studies showing high protein consumption affects calcium balance but what is the real world effect on our overall health.  Just as the doctors feared that low Vit C levels in meat would quickly lead to scurvy, it just hasn’t happened, and no one can satisfactorily explain why.  Either there is more Vit C than people think or something else is going on.  Same with calcium balance.  It was predicted that I’d lose bone density through a variety of mechanism (negative calcium balance, leaching of the bones to off-set my acidic diet etc).  In fact the opposite has happened. 

I no longer obsess over studies that lead to theories not in line with my actual results.  Reality trumps theory in my book.  I’m convinced that the researchers don’t understand all they know about the subject.  I’m also convinced that I don’t have to understand the bio-molecular workings of my body at the cellular level to live an active and productive life.  Maybe it comes down to finally achieving some wisdom along with all that knowledge I have rattling around in my head.

Alphargruis,
I don’t think there is any magic in ZC.  I do think you can over do the carbs and I also think there are some carb sources that are not good food, but other than that I have nothing against them.  A small salad and/or a piece of fruit everyday is probably beneficial and enjoyable as well.  I’ve tried to add this back into my diet but just don’t enjoy it (with the exception of a hand full of cherries or a few grapes a couple of times per year).  I’m fairly close to ZC because that is now what I prefer, not because of any ideological bent.  I started ZC as an adventure and only continue it because I now enjoy eating this way.  If my health were to suffer I’d make a change in a heartbeat. 

Phil,
There are lots of “reasons”, “beliefs” and dare I say a bit of religion when it comes to diet.  KGH et al are free to believe what they wish and I get to believe what I wish.  And just because we believe something, doesn’t make it a correct belief.  In stead I’ll say I’m happy with my results and I know Kurt is thrilled with his.  That’s all that counts.  The diversity of opinion is what fuels our forums and makes things interesting.  One thing I can say is that I have not experienced any of the symptoms you listed with the exception of rapid heart beat and that was transitory.

Michael,
You are correct that I, too, suffer from the occasional bout of zealotry even to this day.  However, I do my best to objectively think things through and I constantly compare my beliefs against real world experience and observations.  I’m amazed how often my most cherished beliefs are struck down when subjected to the light of reality.  So many years wasted blindly following the whims of gurus who knew little more than I did, or clinging to studies and theories that sounded good but weren’t supported by even the most casual observation of the reality around me.

Hanna,
Fat is stored in the form of triglycerides.  A triglyceride is three fatty acid molecules attached to one glycerol molecule.  When fat is broken down, (either through digestion of dietary fat or mobilized from our own fat tissue) the three fatty acid molecules are released and the glycerol molecule is freed.  The glycerol molecule is then free to recombine with another three fatty acids to create another triglyceride, or, it can combine with another free glycerol molecule and be turned into a single molecule of glucose.  For the most part, all this takes place in the liver, but there is some evidence that under certain conditions triglycerides can be formed directly in the fat tissue itself through hormonal and enzyme action, thus bypassing the liver.  As far as I know, the conversion of glycerol into glucose is only done in the liver, but most of this is new science so who knows what we’ll find in the future.

As for your dizziness, this is a common symptom when transitioning from a glucose based metabolism to a fatty acid based metabolism.  The body has been conditioned to use carbs as it’s main fuel and must go through a great deal of effort to reconfigure to efficiently burn fatty acids as its primary fuel.  Of course you were craving fruit.  Every cell and system in your body was screaming for glucose.  The only way to get through this is just to power through it.  Like a drug addict, if you soothe the withdrawal symptoms by supplying the drug, you’ll only prevent or delay the transition.

To efficiently burn fatty acids requires a significant increase of mitochondria at the cellular level.  Yes, mitochondria are there for the basic functioning of the cell, but not enough to allow the cell to efficiently use only fatty acids as its primary fuel source. Glucose metabolism is a “fermentive” process (like yeast fermenting sugar into alcohol) and doesn’t involve mitochondria.   Mitochondria are small cells within the larger cells and they divide and multiply just like the larger host cell of which they are an integral part.  Increasing mitochondria is not an over night process and takes significant time.  In my case, I was over the worst of the transition issues within about 3 months, but my own measurement of Blood Glucose and urine Ketones as well as my annual lab tests, showed that significant changes were still occurring after one year.  If you look at my lab tests from 2007 to present you’ll see ongoing incremental improvement even though my basic diet has remained the same for that entire time.

   
Michael (again)
The idea that consuming some minimum level of carbs is a good thing because it is some how more efficient is just that, an idea, a theory.  It sounds good, but I know of no studies or peer reviewed work that demonstrates that one metabolic pathway is better than another.  They are just different and each meets a specific need of the body under specific conditions.  For years science has told us that red meat and fat causes heart disease and we’ve recently come to question that medical wisdom.  I expect that even if we find some truth in the “carbs are more efficient” theory, there will be much more to the story than first thought.

As for the conversion of glycerol into glucose, it doesn’t account for much glucose as it takes two glycerol molecules to make one molecule of glucose.  In the process 6 fatty acids are freed up, and if not used, thrown away.  This is one of the reasons that people who have been large carb eaters lose so much weight in the first few weeks on a low carb diet.  As explained in my response to Hanna above, in the first few weeks of transition the cells are all screaming for glucose as they can’t efficiently use fatty acids due to lack of mitochondria.  Since dietary carbs are being restricted, large amounts of body fat are mobilized to get at the glycerol to make glucose.  The fatty acids can’t be used and are thrown away by conversion to ketones and excreted through sweat, breath, urine, etc.  This means that as much as 75% of the energy consumed as well as broken down from our own fat stores is discarded.  Much of the dietary fat goes undigested as well.  No wonder we lose weight rapidly.

Over time the cellular mitochondria increase to the point where the cells can efficiently use the fatty acids for fuel.  Urinary ketones will drop dramatically as the fatty acids are now being burned as fuel and not discarded.  And, horrors upon horrors weight loss will stop and even reverse and suddenly calories count again since the body is now efficiently using the fat that is being consumed.  Even worse, if you now start to consume a high level of carbs again, weight will increase rapidly as the fat will be consumed as the primary fuel and the massive rise in Blood Glucose caused by the carbs will be quickly converted to body fat and stored to get it out of the way.

As for paleo use of carbs, your guess is as good as mine.  I wasn’t there, but I do believe we have a ‘sweet tooth’ for a reason.  Seasonal carbs in the form of tart berries and fruits would probably be our source for carbs and since we were using fat as our primary fuel (assuming you believe our primary diet was meat and fat) the carbs eaten in the summer months would quickly fatten us up as our bodies cleared the excessive BG from our systems and this excess weight would prepare us for the lean winter months – that’s my theory anyway, and I’m sticking to it…. Until a better one comes along…..

Phil (again)
Yup, it can take years for things to develop and change, both for the better or the worse.  That is why I get my annual lab work done.  I expect that deficiencies and other problems will show up in the various lab tests long before I notice them affecting me physically.

Wheew, I think I covered everything,
Lex

 

 

[Hanna]

Hi Lex,
Thank you for your explanations. I already used fat as my primary fuel at that time. I ate little fruit, no honey, no or very few cashews and no other food high in carbs, i. e. no more than 100g sugar per day on average, as far as I remember. But it was impossible to cancel fruit/carbs (almost) completely, while eating raw-VEGAN.

Michael,
I think that Wrangham could be right and homo erectus cooked already nearly 2 million years ago.

[majormark]

Lex,

What about the notion that alcohol can help with fat digestion? What do you think about that?

Is it possible that we also consumed carbs to help break down fat?

Aajonus claims that this is one of the reasons to eat fruits (carbs).

[miles]

vegetable & meat don't go together..

[goodsamaritan]

2010 July PDF results of Lex now attached on page 1 of this thread on the very first post for convenience.

Best wishes all.

Thanks for sharing Lex.

[alphagruis]

Hanna, Michael,

As to the glycerol to glucose conversion Lex answered your question and I can't see anything I could add. As he points out this is probably only a minor source of glucose in ZC.

The conversion of amino acids or other metabolites to glucose costs typically 11 ATPs , the cells energy "currency", per glucose molecule ( in case of amino acids). The potential problem with this is not so much the energy expenditure by itself but the fact that the production of the relevant energy in the form ATPs is additional mitochondrial activity (the energy factories of the cells) and thus production of additional reactive oxygen species and in turn additional oxidant stress which is thought to be involved in ageing and wear of cell components. In principle this additional stress is not present when the relevant glucose is obtained directly from diet. As I pointed out before this assumes however that digestion of plant carbs and digestion of fatty meat are comparable in terms of energetic costs and related oxidant stress which is possibly not the case.

Excess nitrogen waste is produced whenever amino acids are converted into glucose, fat or ketonic bodies. And this happens whenever there is an excess of amino acids with respect to the needs of body repair and protein synthesis. So if an excess of protein must indeed be provided by the ZC diet to meet minimal glucose requirements by means of gluconeogenesis from amino acids there is an additional production of nitrogen waste and thus an additional excretion load on kidneys as compared to a situation where the minimal glucose is obtained directly from a diet with the minimal carbs and correspondingly less protein intake. Notice however that if protein intake is the same in this diet as in ZC, nitrogen waste is the same, the only difference being that the excess protein is rather stored in form of fat than glucose.    

Moreover there is the fact I became only aware of recently that there exists according to standard biochemistry knowledge a metabolic pathway that converts pyruvate back to glucose. Pyruvate is a degradation product of glucose in glycolysis, the fermentation process that permits to get part of the energy available in glucose in its initial anaerobic degradation process. Of course the back conversion of pyruvate to glucose also needs energy in the form of ATPs as with gluconeogenesis from amino acids but there is now no production of additional nitrogen waste in this process. Maybe this pathway plays indeed a major role in gluconeogenesis in ZC conditions. In this way glucose could in fact be regenerated indefinitely in a closed cycle with no need of dietary intake at all and no disadvantage in terms of additional nitrogen waste. The energy needed to regenerate the glucose would come from fat oxidation in mitochondria.

So it seem possible from a biochemical point of view that ZC does not necessarily produce additional nitrogen waste but we don't know yet for sure.  

  
 

        

[lex_rooker]

Thanks Goodsamaritan!

Hanna,
How can you possibly know that your body is using fat as its primary fuel source – especially when eating raw Vegan.  The fact that you can’t cancel carbs and are driven to eat them is compelling evidence to the contrary.  Your own evidence shows that your body is glucose driven.  To change it would require that you reduce carbs below 30g/day for several months.  This would be difficult if not impossible on a vegan diet since by definition it is carb based.  We humans have an infinite capacity to rationalize reality to fit what we wish to believe. 


Majormark,
I know nothing about alcohol as I don’t consume it.  I have nothing against it, we just never had alcohol in our house when I was growing up and I never developed a taste for it.  As a teenager I tried drinking with the guys on Friday nights etc but hated the feeling of being out of control so alcohol has just never been part of my life.

Do carbs help break down fat?  No clue.  I have no evidence that carbs are necessary to break down fats.  What peer reviewed evidence does Aajonus provide to support his claims?  Anyone (including me) can claim anything they wish, that doesn’t make it true.  I no longer blindly accept the pontifications of gurus without solid evidence to back it up.


Miles,
How do you know that vegetables and meat don’t go together?  I know that this is the conventional wisdom of the food combining crowd, but I know of no verifiable evidence that this is true.  We have been eating mixed meals for thousands of years and I don’t know of any specific health issue that can be attributed to eating vegetables with meat. I think there is plenty of evidence that over consuming carbs in general, and especially grains, can cause long term health issues, but I’ve seen nothing that supports the food combining theory.  My guess is that it is mostly nonsense like much of the ‘Natural Hygiene’ dogma.

Alphargruis,
Why would we need to be concerned with the “ATP” cost of creating glucose from amino acids?  Every function our body performs has an energy cost.  How do we know that energy accounting at the micro metabolic level is a valid way to determine anything useful?  A specific function may have a high energy cost, but it may lower the overall energy cost to the organism as a whole.  Another function may have a lower initial energy cost but create metabolites that are used far less efficiently and therefore have a much higher overall energy cost.  We have no way of knowing.  I also don’t know of any real world evidence that shows that more damage from oxidative stress is caused by one metabolic function as opposed to another.

As for the fact that nitrogen waste is created when amino acids are converted to glucose, so what?   Nitrogen causing kidney damage has been a favorite theory for years, but it never seems to actually occur in reality – unless of course, the kidneys were already damaged by something else.  A meat and fat diet alone has never been shown to cause the predicted damage.

Not sure what value is to be gained from agonizing over obscure metabolic pathways or that fact that every one of these pathways requires energy to function.  If my body wishes to convert pyruvate into glucose it’s fine with me.  If it decides not to convert pyruvate into glucose that is fine with me also.  I can’t force it to do this nor can I prevent it.  I can’t even tell when it is doing it, or measure how much it has done.  My body is much smarter about these things than I am, so I spend zero time worrying about it.

It is a fool’s errand to make decisions based on trying to force a theoretical outcome of some parameter that we know little or nothing useful about.  For years now we’ve controlled cholesterol through both diet and medication.  We are now able to achieve the theoretical numbers but the patients die from heart disease anyway.  What makes the theories of metabolic energy costs, oxidative stress, kidney damage from nitrogen loads, and all the rest any different?  It’s chasing rainbows.  You may wish to bury yourself in the latest micro metabolic theories, but I prefer to spend what precious time I have left on pursuits that have more immediate tangible benefits.

Lex

[King Salmon]

Majormark/Miles/Lex,  Majormark wrote a post reflecting that AV recomends eating fruits to help digest meats.Then Miles wrote that veggies don't go with meat.
From my experience,those thoughts are backwards.
             Meats with veggies are fine.Meats with fruits are not.

This is from my experience and makes the most sense to me.

Lex,of course on a mono-diet,food combining is a non-issue.