10

votes

Is there something we can attribute to as to why some people don't do well on ZC/VLC diets?

Answered on August 19, 2014
Created December 18, 2011 at 6:12 PM

Hormones? Or some metabolic process? Or is there no way of knowing?

Cc69a51b427eaad36251cce9dcca4d3a

(1074)

on December 24, 2012
at 07:27 AM

lol such a troll comment. its ironic cuz carbsane probably needs a true ZC diet more than anyone

Cc69a51b427eaad36251cce9dcca4d3a

(1074)

on December 24, 2012
at 07:24 AM

lol conciliator is a NOOB

A968087cc1dd66d480749c02e4619ef4

(20436)

on March 14, 2012
at 06:25 PM

Maybe it's the lack of carbs...

24df4e0d0e7ce98963d4641fae1a60e5

on December 20, 2011
at 12:52 PM

@April: I think it was KHG who made the statement once that ketones are more efficient only if you don't look at what goes into making them. Perhaps I need to state this differently. If humans were in ketosis 99% of the time during evolution, why do people even have to "adapt" -- we should feel like total lethargic crap eating carbs and our ancestors doing so would not have survived.

24df4e0d0e7ce98963d4641fae1a60e5

on December 20, 2011
at 12:45 PM

@AndyM: You're the one twisting things about and I have no patience for that. VLC/ZC = essentially carnivore diet. Humans are not carnivores. @Everyone else: My point is not that different cells have preference for different things, it's that when glucose is around, all cells seem to use it, when it's scarce, then they use ketones. IF ketones were biochemically better, why wouldn't the ketotic humans have a survival advantage?

Medium avatar

(10663)

on December 20, 2011
at 03:46 AM

And this article: http://www.annualreviews.org/doi/abs/10.1146/annurev.ph.36.030174.002213 which claims that ketones are the preferred energy source for highly active tissues such as the heart and muscle. On low carb-diets, ketones have a glucoprotective effect, in that they are capable of accommodating a wide range of metabolic demands to sustain body functions and health while not using, and thus sparing, protein from lean muscle tissue.

Medium avatar

(10663)

on December 20, 2011
at 03:39 AM

Has anyone read this article from the NY Times by Taubes who says that "the heart and brain run 25% more efficiently on ketones than on blood sugar." http://www.eabbassi.ir/what%20if%20its%20all%20been%20a%20big%20fat%20lie.pdf (found on page 9)

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 20, 2011
at 01:04 AM

You're still missing the point entirely. No-one is disputing what you say, but it's neither impressive nor particularly meaningful. But if you can't bring yourself to talk to other people, you're not likely to learn any better. And you will continue to fail to explain your points any better. Probably just as well.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 20, 2011
at 12:41 AM

Yes, your personal experience is a counter-example, but you were asking about other people in general.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 20, 2011
at 12:17 AM

Sure we could, but that doesn't lead to an evolutionary advantage for amylase deficiency.

7dc950fc76a046048e683d2a27dced37

on December 20, 2011
at 12:13 AM

Andy, say we grant the heart prefers ketones to glucose. Any reason we couldn't theorize that the reason for that is the same reason our muscle cells become insulin resistant when in ketosis: to preserve glucose for the brain?

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 19, 2011
at 11:47 PM

Try taking a deep breath and reading it again. If you really think it's just me that's come up with the idea that the heart uses ketones more efficiently then argue with Travis about it, don't conflate the issues, and if you don't want to debate the issues quite chucking them out there. Your original rhetoric was so simplistic and reductionist as to not stand in any event. Is this really the level of your reasoning in everything you post?

24df4e0d0e7ce98963d4641fae1a60e5

on December 19, 2011
at 11:04 PM

@AndyM: Perhaps you can provide me with the names and email addresses of those 'authorities' I need to contact who would disagree with my "pandering misconception" that humans are not carnivores and this is likely why most do not do well with extreme carb restriction. I'm not here to debate specifics of what is best for different tissues, but IF ketones are best for the heart, my original rhetorical question stands.

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 19, 2011
at 10:52 PM

I'm going to not bother with Andy but Sara is a computational neuroscientist which is pretty similar to my background (computer science with an interest in the brain) so I will try to explain my points as best I can.

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 19, 2011
at 10:50 PM

@Sara, we do have control over it. Like I said, in every single metabolic ward study isonitrogenous diets do equally well for fat loss. Taubes et als always use horrible data to reach their wrong conclusions. There are many hormones at play for fat loss: ASP, Insulin, Catecholamines, etc. The body will have a net loss of fat when there is a net energy deficit to cover. Lowering carbs will certainly raise FA oxidation, but it will also raise FA absorption (assuming you raise fat intake). Similarly, lowering fat will lower FA oxidation and lower absorption. At the end, it really is kcal in/out.

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 19, 2011
at 10:32 PM

Sigh... You do have control over the fat oxidation... How did Taubes manage to confuse so many people. And I assure you I have experience and empathy in these matters. What I don't have is the inclination to explain nutrition to a bunch of people on the internet who believe in insulin fairies.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 19, 2011
at 10:22 PM

Me too. Still, at least we can let Travis and Evelyn argue about ketones and cardiac tissue on this one.

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 19, 2011
at 10:19 PM

Yes. Some days I think everyone on the internet is conspiring to troll me.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 19, 2011
at 08:03 PM

I don't know if it's a lack of personal experience, or a lack of empathy having overcome these challenges successfully, but seem people really seem determined to miss the point in hammering home their idealogy. Diligence is not an independent variable in this system.

Medium avatar

(39821)

on December 19, 2011
at 07:55 PM

Oh btw, the heart does use ketone-bodies in preference to glucose or fatty acids. Organ fuel substrate preference is an interesting topic. The overall arc of it is to spare glucose for the brain during starvation/carb restriction. The brain never stops needing some glucose every day.

Medium avatar

(39821)

on December 19, 2011
at 07:50 PM

Conciliator, Evelyn...ever feel like this on PaleoHacks? : http://i41.tinypic.com/2ajqi3l.gif ?

7841848bd0c27c64353c583fb7971242

(7275)

on December 19, 2011
at 07:40 PM

It's not that thermodynamics is broken, it's that the fat oxidation part of the equation depends on a dynamical system that we don't have control over.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 19, 2011
at 07:33 PM

I just find your whole argument misrepresentative, pandering to common misconceptions rather than actually using stronger arguments for not eating ZC. You may disagree but I think it's more helpful to acknowledge that there is some debate. I trust you are aware at least that many of the 'authorities' on paleo (as well as low-carb, and in fact conventional) nutrition, believe that glucose is not the best fuel for the heart? If you have definitive evidence to the contrary you should let them know instead of just hinting at it on informal sites like this.

24df4e0d0e7ce98963d4641fae1a60e5

on December 19, 2011
at 07:26 PM

Where's the evidence that the heart "prefers" ketones? I take it you agree we're an omnivorous species? If so, I don't see what the issue is with what I wrote. I'm not phrasing questions to paint some particular picture, I'm asking how what we do know and observe about human metabolism of living beings squares with this fairy tale that humans were somehow intended to be ZC/VLC. And that was my point. We're not.

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 19, 2011
at 07:19 PM

Advice is always insufficient, it takes action. If you don't have the diligence to keep up a caloric deficit that doesn't mean thermodynamics is broken.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 19, 2011
at 07:08 PM

I was thinking of the heart rather than the brain. And we weren't 'intended' to operate on anything. Clearly there has been an advantage to remaining omnivorous in terms of our adaptability, however it also seems reasonable that we would have a flexible diet if you consider our evolution from a plant-based diet to increasing consumption of meat. We may not have all the answers, but why try and paint a particular picture by phrasing questions as if we do?

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 19, 2011
at 07:06 PM

Funny, yet not a single one ever found in a study.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 19, 2011
at 07:02 PM

Keep telling yourself that conciliator, but there's millions of people who have found that advice insufficient.

24df4e0d0e7ce98963d4641fae1a60e5

on December 19, 2011
at 06:53 PM

@Andy: (hate those character limits) As much as I try to back my blog posts with scientific references, I'm limited in time for doing same here. The way I look at it too, unless challenged for "proof" I'll post thoughts. Re: ketones, show me the evidence that the brain prefers ketones to glucose. Epiletics don't count.

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 19, 2011
at 06:43 PM

Net fat flux = Fat storage - Fat oxidation. ZC/VLC turns on fat oxidation (via insulin), low fat decreases fat storage (via ASP), so the only thing that matters at the end of the day that matters for fat loss is presence of a net caloric deficit or not.

1c67bc28f4e44bbb8770b86df0463df3

(6719)

on December 19, 2011
at 06:39 PM

ZC/VLC does NOT trigger an emergency starvation state, a starvation state, DEFCON 1, a state of starvation, an emergency or even a news bulletin. ZC/VLC turns on fat oxidation of either dietary or stored fat, and that is all.

24df4e0d0e7ce98963d4641fae1a60e5

on December 19, 2011
at 06:26 PM

@Andy: Perhaps glucose is needed here ;-) Seriously, though, my original post began with the FACT that humans are not carnivores. Compare our physiology to obligate carnivores and this is abundantly clear. Nor are we herbivores ... again compare the physiology. Feed an herbivore animal flesh and it's not a good scene. What I'm saying is that we have a marvelous flexible digestive and metabolic system to operate on a mixed diet. Why would we have these if we weren't intended to? The rhetorical questions are not 2 appeal 2 a very low denominator, but to get some to question 4 themselves.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 19, 2011
at 05:40 PM

Sorry Evelyn, are you just casually asserting that ketones aren't preferrable for some tissues? I was going to start responding to the rest of your edit but it's all just so illogical I couldn't work out where to start. Have you really not come across the theories which answer your rhetorical questions? You may disagree with them based on your own extensive research, but simply presenting them as seemingly obvious holes is comparable to saying "if eating meat is necessary, why are there herbivores?" Appealing to a very low denominator.

F0e558010a2ecb31fa37b7c491596b8e

(3850)

on December 19, 2011
at 05:35 PM

Had I grown up eating a more moderate (lower, healthy carb) diet, I may be able to exist happily on that for the duration, but I feel like my metabolism has been do damaged during my first 30 years that I have no choice but to go down the opposite path to what brought me here.

F0e558010a2ecb31fa37b7c491596b8e

(3850)

on December 19, 2011
at 05:35 PM

My personal experience has been the exact opposite. I ate a SAD high carb diet for most of my life and progressed from a healthy kid, to a moderately unhealthy overweight young-adult, to a very unhealthy overweight adult. Eating lower carb, and being in ketosis (which I have done on and off for a decade) is the best and healthiest I've felt in my life.

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 19, 2011
at 04:40 PM

Evelyn, I get your point :)

Ed71ab1c75c6a9bd217a599db0a3e117

(25472)

on December 19, 2011
at 04:20 PM

and all have been shown to extend lifespan too.........what was perfect at 40 is not perfect later in life when our biology changes.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 19, 2011
at 12:54 PM

Your comments suggest you either have completely missed the point or are deliberately rejecting it, without any good reason.

24df4e0d0e7ce98963d4641fae1a60e5

on December 19, 2011
at 12:38 PM

I see we have CDS sufferers that need to watch this BBC Program. It's 5 parts on YouTube, I've linked to them all here: http://carbsanity.blogspot.com/2011/01/must-see-tv-for-those-suffering-from.html

24df4e0d0e7ce98963d4641fae1a60e5

on December 19, 2011
at 12:16 PM

@Huey: Do you really believe that excess dietary carb gets stored as body fat but excess dietary fat does not?

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 19, 2011
at 01:55 AM

There are certain things that are absolute, like thermodynamics, and in that case there is no need to say 'it depends'. But listen, you clearly have your mind made up, so does Huey. Do whatever the hell you guys want, I couldn't care less.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 19, 2011
at 01:54 AM

Well, as I'm sure you're aware, that's functionally useless, and not how most people would use or interpret the expression 'calories in/calories out'.

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 19, 2011
at 01:51 AM

I mean the major determinant of changes in bodyfat (99%) is caloric balance. Meaning, change in bodyfat ~ calories absorbed - calories used. The body has no problem absorbing calories as fat or carbs. Yes things like trans fats make a small difference but that's in the 1%. That's what the science says, for equal protein intakes the major determinant is calories. I'll add that in general carbs take more energy to digest than fat (Carbs ~90% digestion efficiency, fat like 95%), *especially* when fiber is considered. Huey having diarrhea once proves nothing.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 19, 2011
at 01:46 AM

Also, there is a distinct lack of "it depends, we don't know, and moderation" in that comment. Top marks for irony.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 19, 2011
at 01:45 AM

But what do you mean by calories in/calories out? Your comments suggest you either have completely missed the point or are deliberately rejecting it, without any good reason.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 19, 2011
at 01:43 AM

self-reported...

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 19, 2011
at 01:42 AM

And for weight loss purposes it is calories in/calories out. Find me an isonitrogenous metabolic ward study that shows the opposite.

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 19, 2011
at 01:42 AM

"less balanced comments" that's funny considering every comment I post is: it depends, we don't know, and moderation.

93ae9f2d376e5426e891a9b58d8302fa

(2936)

on December 18, 2011
at 11:56 PM

I prefer a hash of tripe ;)

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 18, 2011
at 11:52 PM

I just told you what my position is. Why are you desperately trying to reduce it to a meme? I'm all for shooting down conciliator's less balanced comments but it really doesn't help when you make such a hash of it. If you must, make a hash of sweet potato. Goes great with eggs in the morning.

93ae9f2d376e5426e891a9b58d8302fa

(2936)

on December 18, 2011
at 11:41 PM

You're saying yes, it's calories in/ calories out. Don't deny that's your position.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 18, 2011
at 11:34 PM

What's going on? People have been upvoting an answer that's not only civil but also doesn't contain personal ego and may even be helpful. I don't understand.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 18, 2011
at 11:32 PM

Nope, some us have just learned how and when to apply it. Zero calories in and eventually you'll die. 20000 calories in and I don't much fancy your chances either. By definition, if you eat to excess then you are eating more than your body can deal with and so it will store some of it.

93ae9f2d376e5426e891a9b58d8302fa

(2936)

on December 18, 2011
at 11:11 PM

Calories in/calories out, eh? I thought we were over that.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 18, 2011
at 11:09 PM

Well if it's excess it's excess huey. And it doesn't stop ketosis, just the release of fatty acids. But then carbs will do the same *and* stop ketosis for a while. You can miseat whatever plan you use.

93ae9f2d376e5426e891a9b58d8302fa

(2936)

on December 18, 2011
at 11:04 PM

Excess dietary fat forestalls ketosis and keeps you from burning your body fat. Excess dietary fat does NOT produce new body fat.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 18, 2011
at 10:59 PM

Excess everything gets stored as body fat. Because the body expects that at some time it's not going have an excess any more. It's a lot easier to stop eating for a time if you're used to eating more fat than carbs though. Even the carbivores here say you need to eat regularly to maintain function. Seems disfunctional to me.

93ae9f2d376e5426e891a9b58d8302fa

(2936)

on December 18, 2011
at 10:51 PM

Nope. It fed to the little beasties at the sewage treatment plant.

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 18, 2011
at 10:48 PM

... Excess dietary fat gets stored as body fat.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 18, 2011
at 10:42 PM

No. You're not starving. I'm starting to wonder if you ever even read anything, or whether you're deliberately droning out CW responses.

93ae9f2d376e5426e891a9b58d8302fa

(2936)

on December 18, 2011
at 10:39 PM

It's not a question of whether glucose or dietary fat gets burned first. I.e., which is "preferential", blah blah. That can only be tested when both are ingested at the same time, which invalidates the alleged importance of the test. The true important thing is that excess carbs - ingested alone - get stored as body fat. Dietary fat, not so. It's not a race to the metabolic finish line.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 18, 2011
at 10:35 PM

It's not difficult to get into or maintain ketosis, we do it constantly, particularly when asleep but most of the day as well on some level. If we consume lots of glucose, we have to get rid of it straight away. Our metabolism even speeds up just to burn it off. It's preferential, but not because it's preferred. People are guided much more by their beliefs than their body.

Medium avatar

(39821)

on December 18, 2011
at 10:28 PM

*Most* people don't do well on ZC/VLC because it triggers an emergency starvation state, no matter how many calories are consumed. Many can ignore/tolerate the consequences of that state, and for some it's realistically the healthiest thing that they'll ever do, but it's by no means the default human way of eating.

5ef574d7893bc816ec52e04139e9bc09

(6097)

on December 18, 2011
at 10:16 PM

http://www.youtube.com/watch?v=woySeSNBL3o&feature=related

24df4e0d0e7ce98963d4641fae1a60e5

on December 18, 2011
at 10:02 PM

But Amber, our livers can store a couple hundred grams of glycogen. That should be more than sufficient if we evolved in an essentially carb-free environment. Even in the most IR state, we still metabolize SOME glucose in our skeletal muscle. Why would that be? As to #3, that's why it is what it is, but why don't our muscles take up the fatty acids and burn them right off? Why should we have to ADAPT, I guess, is ultimately the question.

100fd85230060e754fc13394eee6d6f1

(18706)

on December 18, 2011
at 09:56 PM

(1) and (2) because we want to get rid of glucose quickly if it's there. (3) If we used it all immediately, we'd have to eat constantly. Instead we store and use it as we need it.

C56baa1b4f39839c018180bf63226f7d

(3499)

on December 18, 2011
at 09:14 PM

http://www.proteinpower.com/drmike/uncategorized/why-do-we-need-glucose/ is about as good as I can find after keyword searching for now. As for the second part of your first question, I think the difficulty of maintaining ketosis has more to do with our perception of our food supply than any biological imperative. There was a rat study (I know, weak correlation to humans) that showed that rats would modify their dietary macronutrients (carb/fat/protein) through only a change the amount of each available. It seems that being more like the Maasai or the Kitavans has much to do with what's to eat

93f44e8673d3ea2294cce085ebc96e13

(10502)

on December 18, 2011
at 09:03 PM

@Bill1102inf -- watch the tone & timbre of your language. If your use of inflammatory language continues, you will be suspended or deleted.

24df4e0d0e7ce98963d4641fae1a60e5

on December 18, 2011
at 09:00 PM

http://carbsanity.blogspot.com/2010/07/nutrient-fates-after-absorption.html Not enough carbs around Bill?? Yeah, no plants ever stored energy as starch. Ha!

9205855633f4d88fd78339aad4fc54ff

on December 18, 2011
at 08:54 PM

(forgive my english) "Well" standing for? Weight-Loss, Well-Being, enjoyment. high intensity sports and activities? Or probably you mean all the above and some. But they'd be, for me, all a bit different answers. Only to start: not further defined VLC shouldn't be intended for weight-loss as some do. Not being carbs the only fattening macronutrient- People gorging on bacon (while avoiding like the plague even 20+20 gr of glucose) aiming on a six-pack, probably won't do so "well" if you ask me (and I'd say decades of bodybuilders and figure skaters too).

1c67bc28f4e44bbb8770b86df0463df3

(6719)

on December 18, 2011
at 08:33 PM

Simple: http://www.scienceschool.usyd.edu.au/history/2009/media/lectures/4-brand-miller-chapter.pdf People were in ketosis because there simply was not enough carbs around for them not to be. Why is this so hard to get through to the Paleo Theater crowd?

C56baa1b4f39839c018180bf63226f7d

(3499)

on December 18, 2011
at 08:33 PM

I'll see if I can find Dr. Eades's post about why glucose is preferentially used for fuel, but the gist of it is that humans have a strictly limited storage mechanism for sugars (BG and glycogen) and excess of sugar is toxic. It's why alcohol is preferentially used for fuel over glucose -- there's no storage mechanism for it, it's toxic in excess, and its first-level metabolite is toxic at an even smaller threshold. Now, the body can convert and store sugars as fats, but then they're acted upon like any other fats, which can be stored for effectively ever.

24df4e0d0e7ce98963d4641fae1a60e5

on December 18, 2011
at 08:22 PM

Bill, you must be learning a different human metabolism. Our metabolisms are geared to burn glucose first, proteins as needed in excess, and fats last. Secondly, I said why DON'T we convert them right off? I know how ketones are formed. Point 3 is important because if muscles were used for glucose storage, not usage, there would be a route for glucose EXPORT when the brain needed it. Show me one study that supports your "indisputable fact" that billions of humans spent most of their lives in a ketogenic state. You're not my personal researcher, yikes if you were! ... I'm asking for ONE.

C56baa1b4f39839c018180bf63226f7d

(3499)

on December 18, 2011
at 08:09 PM

Bill, I agree with the points you are making, but you could seriously tone down the delivery. This is not a political blog.

F52b51135f2c47eb46c986fdc9760b9b

(180)

on December 18, 2011
at 07:54 PM

Thanks for the great links. You know, I think the most important lesson I've learned from the paleo movement and from paleohacks is that there really is a wide variation between how individuals react to different diets and eating plans. Nice to see that going down to the genetic level has produced such useful results. Hopefully we'll see a lot more studies like this done in the future.

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 18, 2011
at 07:47 PM

You are clearly hopeless.

24df4e0d0e7ce98963d4641fae1a60e5

on December 18, 2011
at 07:47 PM

This is very interesting, and certainly anyone who observes the diversity of what different folks thrive on cannot deny this. I think the longest VLC has been looked at, however, is 6 months and after that we have only the reports from a few identified advocates, and a whole lot of anonymous ones. Such anecdotes cannot be verified. I would mention that the chief investigator of that 6 month study, Dr. Eric Westman, either doesn't follow the diet himself or it's not working too well. He's notably heavier now than he was just a few short years ago. Sorry, this sort of thing bugs me.

1c67bc28f4e44bbb8770b86df0463df3

(6719)

on December 18, 2011
at 07:44 PM

Yes, LETS BE honest about ketosis. It is an indisputable fact that Billions of human beings spent most of their lives in a ketogenic state, furthermore there are PLENTY of studies on this, I am not your personal researcher but you can easily look this up if you know what google is. In addition there are also plenty of studies which show a sharp decline in human health upon the introduction of 'farming' and the consumption of grains/carbs.

1c67bc28f4e44bbb8770b86df0463df3

(6719)

on December 18, 2011
at 07:39 PM

#1:(A LIE) We DO NOT burn glucose preferentially unless we are performing an Anaerobic activity. Cells, especially muscle cells preferentially use fatty-acids for energy even when consuming a high carb diet. #2 (another LIE) We do not immediately convert fatty acids into ketones. Free Fatty Acids are readily used for energy by all cells in the body except the brain, which prefers ketones. Ketones are a BY PRODUCT of lipid oxidation. 3: Is this even a question? Yes, muscles which are NOT full, are a sink for both dietary glucose AND Gluconeogenesis created glucose, you have no point.

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 18, 2011
at 07:35 PM

And let's be honest, nobody knows the long term effects of ketosis. It is perfectly plausible that they could contribute to pathologies in the same way that they certainly help other pathologies (seizures). So are ketones toxic? Nobody knows. Saying yes or no is premature.

93ae9f2d376e5426e891a9b58d8302fa

(2936)

on December 18, 2011
at 07:18 PM

I'm on bills side. http://tinyurl.com/3jqbmuo

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 18, 2011
at 07:10 PM

Bill, I hope for your sake that **you** are a troll, else you are hopeless.

24df4e0d0e7ce98963d4641fae1a60e5

on December 18, 2011
at 07:09 PM

Seems you've made a trolling comment. Did I say ketones were toxic? Umm ... no.

1c67bc28f4e44bbb8770b86df0463df3

(6719)

on December 18, 2011
at 07:05 PM

What a Troll response, for anyone reading this that is new to Paleo/Prumal, there is a TON of misinformation and what is written above only adds to the spread of misinformation. You can google ketones are toxic and find 100's of websites stating this (its a LIE!), those same websites are ALL trying to sell you some STUPID supplement or are written by vegetarians who have had their position blown out of the water by paleo/primal.

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 18, 2011
at 06:56 PM

Everything I've read has led me to believe there are only a couple truths to dieting. 1) Hit protein/EFA thresholds 2) Fat/carbs **depend**. In general, the leaner and more active you are the more carbs you will do better with. Genetic factors also play an important role.

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5 Answers

15
7dc950fc76a046048e683d2a27dced37

on December 18, 2011
at 06:32 PM

Some initial research is suggesting that genetics may play a role. In his very interesting A to Z diet study, Christopher Gardner of Stanford found that within each diet group, some women did well and others not so well.

Researchers at a genetics testing lab asked for and got access to a little fewer than half of the original participants and tested their DNA for specific genes the company had linked to weight loss. They found:

Women assigned to a genotype-appropriate diet lost 5.3% of their body weight compared with just 2.3% among those not matched to genotype (p=0.005). Within the Atkins group, for example, those appropriately assigned by genotype lost approximately 12 pounds compared with 2 pounds for those who lacked the low-carbohydrate genotype. In the Ornish group, similar reductions in weight were observed among those appropriately assigned by genotype.

Gardner said the proportion of individuals who were genetically predisposed to the low-fat or low-carbohydrate diets is roughly 50-50, so a significant number of people will fall into each category. He stressed, however, that all individuals assigned to the diet groups were instructed to make healthy, wholesome food choices.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 18, 2011
at 11:34 PM

What's going on? People have been upvoting an answer that's not only civil but also doesn't contain personal ego and may even be helpful. I don't understand.

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 18, 2011
at 06:56 PM

Everything I've read has led me to believe there are only a couple truths to dieting. 1) Hit protein/EFA thresholds 2) Fat/carbs **depend**. In general, the leaner and more active you are the more carbs you will do better with. Genetic factors also play an important role.

F52b51135f2c47eb46c986fdc9760b9b

(180)

on December 18, 2011
at 07:54 PM

Thanks for the great links. You know, I think the most important lesson I've learned from the paleo movement and from paleohacks is that there really is a wide variation between how individuals react to different diets and eating plans. Nice to see that going down to the genetic level has produced such useful results. Hopefully we'll see a lot more studies like this done in the future.

24df4e0d0e7ce98963d4641fae1a60e5

on December 18, 2011
at 07:47 PM

This is very interesting, and certainly anyone who observes the diversity of what different folks thrive on cannot deny this. I think the longest VLC has been looked at, however, is 6 months and after that we have only the reports from a few identified advocates, and a whole lot of anonymous ones. Such anecdotes cannot be verified. I would mention that the chief investigator of that 6 month study, Dr. Eric Westman, either doesn't follow the diet himself or it's not working too well. He's notably heavier now than he was just a few short years ago. Sorry, this sort of thing bugs me.

11
7c2b34b8626dc30e40567283c4ad1e1c

on December 18, 2011
at 08:54 PM

  • Liberation of free fatty acids interrupts thyroid signalling (especially pufa)
  • Increased susceptibility to stress (dependence on stress hormones for sugar)
  • Increase tryptophan intake (increases serotonin= increased inflammation, hypoglycemia, estrogen, prolactin)
  • Decreased CO2 (sugar, calcium, salt, and thyroid all increase CO2)
  • High phosphate content (in the face of low calcium), increase PTH (pro-inflammation)
  • Decreased glycogen storage (insufficient sugar if VLC/ZC)
  • Low-blood sugar (possibly decreasing tolerance to food allergens)

Ed71ab1c75c6a9bd217a599db0a3e117

(25472)

on December 19, 2011
at 04:20 PM

and all have been shown to extend lifespan too.........what was perfect at 40 is not perfect later in life when our biology changes.

8
24df4e0d0e7ce98963d4641fae1a60e5

on December 18, 2011
at 06:37 PM

Probably because humans are not carnivores. Plain and simple. There is NO evidence for this to be the case.

Consider this from the paleo/evolutionary perspective. IF ketones and fats were the "preferred fuel" for the human body, and we evolved in an environment of scant carbohydrate availability, why:

  1. Do we still burn glucose preferentially and find it so difficult to get into let alone maintain any significant level of ketosis?

  2. Don't we immediately convert fatty acids to ketones (instead of only when we're low on glucose) for our brains to consume from the get-go?

  3. Is skeletal muscle the biggest "sink" to dispose of dietary glucose, and most dietary fats go to adipose tissue first?

VLC is the adapted, nutritional state of necessity for humans in certain environment. There's little evidence it's optimal, and a ton of evidence for more optimal nutrition.

EDIT TO ADD:

It seems to me that the term "preferred" or "preferential" is emotionally charged for some. But the heirarchy of substrate metabolism for energy is well established and irrefutable. There are also metabolic disorders that exist in enough of the human population to where if they were advantageous we would imagine they would have been selected for by evolution. If humans didn't consume starch, why do we still have amylase? If dietary glucose was harmful, and ketones actually preferred by certain tissues as an energy source, wouldn't humans deficient in amylase have had a survival advantage and won out in the evolutionary process? This is what I was getting at. One would think that over thousands of millenia the enzymes for ketone generation would be so upregulated, and those for glycolysis so downregulated we'd just convert dietary fat to ketones and be done with it, even if a little glucose came our way, because our livers would be more than capable of handling that with its glycogen storage capacity.

Another thing to consider is how substrate levels in circulation are regulated. In large part, dietary fats do not contribute to fatty acid supply, that is regulated at the point of release from fat tissue. We certainly could have a similar process for glucose, where it went straight to glycogen and was released when needed. Glycogen is inefficient compared to fat for energy storage, but surely we could have double or triple the capacity without becoming prohibitively heavy. Glucose stimulates its own oxidation. If this were because it's toxic why absorb it at all?? We don't have enzymes to digest oligosaccharides, why do we have them for di and poly? Why have the metabolic path to convert carbs to fat but not vice versa? If we never ate much to begin with, let alone excessive amounts, what would be the point? Untreated diabetics survive short term hyperglycemia and what's wrong with a little glucosuria amongst friends anyway?

Hopefully this made my point more and not less clear :)

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 19, 2011
at 04:40 PM

Evelyn, I get your point :)

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 19, 2011
at 01:54 AM

Well, as I'm sure you're aware, that's functionally useless, and not how most people would use or interpret the expression 'calories in/calories out'.

5ef574d7893bc816ec52e04139e9bc09

(6097)

on December 18, 2011
at 10:16 PM

http://www.youtube.com/watch?v=woySeSNBL3o&feature=related

24df4e0d0e7ce98963d4641fae1a60e5

on December 18, 2011
at 08:22 PM

Bill, you must be learning a different human metabolism. Our metabolisms are geared to burn glucose first, proteins as needed in excess, and fats last. Secondly, I said why DON'T we convert them right off? I know how ketones are formed. Point 3 is important because if muscles were used for glucose storage, not usage, there would be a route for glucose EXPORT when the brain needed it. Show me one study that supports your "indisputable fact" that billions of humans spent most of their lives in a ketogenic state. You're not my personal researcher, yikes if you were! ... I'm asking for ONE.

93ae9f2d376e5426e891a9b58d8302fa

(2936)

on December 18, 2011
at 11:41 PM

You're saying yes, it's calories in/ calories out. Don't deny that's your position.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 19, 2011
at 01:46 AM

Also, there is a distinct lack of "it depends, we don't know, and moderation" in that comment. Top marks for irony.

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 19, 2011
at 01:55 AM

There are certain things that are absolute, like thermodynamics, and in that case there is no need to say 'it depends'. But listen, you clearly have your mind made up, so does Huey. Do whatever the hell you guys want, I couldn't care less.

93ae9f2d376e5426e891a9b58d8302fa

(2936)

on December 18, 2011
at 10:51 PM

Nope. It fed to the little beasties at the sewage treatment plant.

93ae9f2d376e5426e891a9b58d8302fa

(2936)

on December 18, 2011
at 11:04 PM

Excess dietary fat forestalls ketosis and keeps you from burning your body fat. Excess dietary fat does NOT produce new body fat.

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 18, 2011
at 10:48 PM

... Excess dietary fat gets stored as body fat.

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 18, 2011
at 07:35 PM

And let's be honest, nobody knows the long term effects of ketosis. It is perfectly plausible that they could contribute to pathologies in the same way that they certainly help other pathologies (seizures). So are ketones toxic? Nobody knows. Saying yes or no is premature.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 18, 2011
at 10:35 PM

It's not difficult to get into or maintain ketosis, we do it constantly, particularly when asleep but most of the day as well on some level. If we consume lots of glucose, we have to get rid of it straight away. Our metabolism even speeds up just to burn it off. It's preferential, but not because it's preferred. People are guided much more by their beliefs than their body.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 18, 2011
at 11:09 PM

Well if it's excess it's excess huey. And it doesn't stop ketosis, just the release of fatty acids. But then carbs will do the same *and* stop ketosis for a while. You can miseat whatever plan you use.

1c67bc28f4e44bbb8770b86df0463df3

(6719)

on December 18, 2011
at 07:05 PM

What a Troll response, for anyone reading this that is new to Paleo/Prumal, there is a TON of misinformation and what is written above only adds to the spread of misinformation. You can google ketones are toxic and find 100's of websites stating this (its a LIE!), those same websites are ALL trying to sell you some STUPID supplement or are written by vegetarians who have had their position blown out of the water by paleo/primal.

24df4e0d0e7ce98963d4641fae1a60e5

on December 18, 2011
at 09:00 PM

http://carbsanity.blogspot.com/2010/07/nutrient-fates-after-absorption.html Not enough carbs around Bill?? Yeah, no plants ever stored energy as starch. Ha!

1c67bc28f4e44bbb8770b86df0463df3

(6719)

on December 18, 2011
at 07:44 PM

Yes, LETS BE honest about ketosis. It is an indisputable fact that Billions of human beings spent most of their lives in a ketogenic state, furthermore there are PLENTY of studies on this, I am not your personal researcher but you can easily look this up if you know what google is. In addition there are also plenty of studies which show a sharp decline in human health upon the introduction of 'farming' and the consumption of grains/carbs.

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 18, 2011
at 07:47 PM

You are clearly hopeless.

24df4e0d0e7ce98963d4641fae1a60e5

on December 18, 2011
at 07:09 PM

Seems you've made a trolling comment. Did I say ketones were toxic? Umm ... no.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 18, 2011
at 11:52 PM

I just told you what my position is. Why are you desperately trying to reduce it to a meme? I'm all for shooting down conciliator's less balanced comments but it really doesn't help when you make such a hash of it. If you must, make a hash of sweet potato. Goes great with eggs in the morning.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 19, 2011
at 01:43 AM

self-reported...

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 18, 2011
at 11:32 PM

Nope, some us have just learned how and when to apply it. Zero calories in and eventually you'll die. 20000 calories in and I don't much fancy your chances either. By definition, if you eat to excess then you are eating more than your body can deal with and so it will store some of it.

C56baa1b4f39839c018180bf63226f7d

(3499)

on December 18, 2011
at 09:14 PM

http://www.proteinpower.com/drmike/uncategorized/why-do-we-need-glucose/ is about as good as I can find after keyword searching for now. As for the second part of your first question, I think the difficulty of maintaining ketosis has more to do with our perception of our food supply than any biological imperative. There was a rat study (I know, weak correlation to humans) that showed that rats would modify their dietary macronutrients (carb/fat/protein) through only a change the amount of each available. It seems that being more like the Maasai or the Kitavans has much to do with what's to eat

1c67bc28f4e44bbb8770b86df0463df3

(6719)

on December 18, 2011
at 07:39 PM

#1:(A LIE) We DO NOT burn glucose preferentially unless we are performing an Anaerobic activity. Cells, especially muscle cells preferentially use fatty-acids for energy even when consuming a high carb diet. #2 (another LIE) We do not immediately convert fatty acids into ketones. Free Fatty Acids are readily used for energy by all cells in the body except the brain, which prefers ketones. Ketones are a BY PRODUCT of lipid oxidation. 3: Is this even a question? Yes, muscles which are NOT full, are a sink for both dietary glucose AND Gluconeogenesis created glucose, you have no point.

1c67bc28f4e44bbb8770b86df0463df3

(6719)

on December 18, 2011
at 08:33 PM

Simple: http://www.scienceschool.usyd.edu.au/history/2009/media/lectures/4-brand-miller-chapter.pdf People were in ketosis because there simply was not enough carbs around for them not to be. Why is this so hard to get through to the Paleo Theater crowd?

100fd85230060e754fc13394eee6d6f1

(18706)

on December 18, 2011
at 09:56 PM

(1) and (2) because we want to get rid of glucose quickly if it's there. (3) If we used it all immediately, we'd have to eat constantly. Instead we store and use it as we need it.

93ae9f2d376e5426e891a9b58d8302fa

(2936)

on December 18, 2011
at 10:39 PM

It's not a question of whether glucose or dietary fat gets burned first. I.e., which is "preferential", blah blah. That can only be tested when both are ingested at the same time, which invalidates the alleged importance of the test. The true important thing is that excess carbs - ingested alone - get stored as body fat. Dietary fat, not so. It's not a race to the metabolic finish line.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 19, 2011
at 01:45 AM

But what do you mean by calories in/calories out? Your comments suggest you either have completely missed the point or are deliberately rejecting it, without any good reason.

C56baa1b4f39839c018180bf63226f7d

(3499)

on December 18, 2011
at 08:09 PM

Bill, I agree with the points you are making, but you could seriously tone down the delivery. This is not a political blog.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 18, 2011
at 10:59 PM

Excess everything gets stored as body fat. Because the body expects that at some time it's not going have an excess any more. It's a lot easier to stop eating for a time if you're used to eating more fat than carbs though. Even the carbivores here say you need to eat regularly to maintain function. Seems disfunctional to me.

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 19, 2011
at 01:51 AM

I mean the major determinant of changes in bodyfat (99%) is caloric balance. Meaning, change in bodyfat ~ calories absorbed - calories used. The body has no problem absorbing calories as fat or carbs. Yes things like trans fats make a small difference but that's in the 1%. That's what the science says, for equal protein intakes the major determinant is calories. I'll add that in general carbs take more energy to digest than fat (Carbs ~90% digestion efficiency, fat like 95%), *especially* when fiber is considered. Huey having diarrhea once proves nothing.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 20, 2011
at 12:17 AM

Sure we could, but that doesn't lead to an evolutionary advantage for amylase deficiency.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 19, 2011
at 07:33 PM

I just find your whole argument misrepresentative, pandering to common misconceptions rather than actually using stronger arguments for not eating ZC. You may disagree but I think it's more helpful to acknowledge that there is some debate. I trust you are aware at least that many of the 'authorities' on paleo (as well as low-carb, and in fact conventional) nutrition, believe that glucose is not the best fuel for the heart? If you have definitive evidence to the contrary you should let them know instead of just hinting at it on informal sites like this.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 19, 2011
at 10:22 PM

Me too. Still, at least we can let Travis and Evelyn argue about ketones and cardiac tissue on this one.

93ae9f2d376e5426e891a9b58d8302fa

(2936)

on December 18, 2011
at 07:18 PM

I'm on bills side. http://tinyurl.com/3jqbmuo

24df4e0d0e7ce98963d4641fae1a60e5

on December 18, 2011
at 10:02 PM

But Amber, our livers can store a couple hundred grams of glycogen. That should be more than sufficient if we evolved in an essentially carb-free environment. Even in the most IR state, we still metabolize SOME glucose in our skeletal muscle. Why would that be? As to #3, that's why it is what it is, but why don't our muscles take up the fatty acids and burn them right off? Why should we have to ADAPT, I guess, is ultimately the question.

7dc950fc76a046048e683d2a27dced37

on December 20, 2011
at 12:13 AM

Andy, say we grant the heart prefers ketones to glucose. Any reason we couldn't theorize that the reason for that is the same reason our muscle cells become insulin resistant when in ketosis: to preserve glucose for the brain?

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 18, 2011
at 07:10 PM

Bill, I hope for your sake that **you** are a troll, else you are hopeless.

C56baa1b4f39839c018180bf63226f7d

(3499)

on December 18, 2011
at 08:33 PM

I'll see if I can find Dr. Eades's post about why glucose is preferentially used for fuel, but the gist of it is that humans have a strictly limited storage mechanism for sugars (BG and glycogen) and excess of sugar is toxic. It's why alcohol is preferentially used for fuel over glucose -- there's no storage mechanism for it, it's toxic in excess, and its first-level metabolite is toxic at an even smaller threshold. Now, the body can convert and store sugars as fats, but then they're acted upon like any other fats, which can be stored for effectively ever.

93ae9f2d376e5426e891a9b58d8302fa

(2936)

on December 18, 2011
at 11:56 PM

I prefer a hash of tripe ;)

93f44e8673d3ea2294cce085ebc96e13

(10502)

on December 18, 2011
at 09:03 PM

@Bill1102inf -- watch the tone & timbre of your language. If your use of inflammatory language continues, you will be suspended or deleted.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 19, 2011
at 05:40 PM

Sorry Evelyn, are you just casually asserting that ketones aren't preferrable for some tissues? I was going to start responding to the rest of your edit but it's all just so illogical I couldn't work out where to start. Have you really not come across the theories which answer your rhetorical questions? You may disagree with them based on your own extensive research, but simply presenting them as seemingly obvious holes is comparable to saying "if eating meat is necessary, why are there herbivores?" Appealing to a very low denominator.

24df4e0d0e7ce98963d4641fae1a60e5

on December 19, 2011
at 07:26 PM

Where's the evidence that the heart "prefers" ketones? I take it you agree we're an omnivorous species? If so, I don't see what the issue is with what I wrote. I'm not phrasing questions to paint some particular picture, I'm asking how what we do know and observe about human metabolism of living beings squares with this fairy tale that humans were somehow intended to be ZC/VLC. And that was my point. We're not.

Medium avatar

(39821)

on December 19, 2011
at 07:55 PM

Oh btw, the heart does use ketone-bodies in preference to glucose or fatty acids. Organ fuel substrate preference is an interesting topic. The overall arc of it is to spare glucose for the brain during starvation/carb restriction. The brain never stops needing some glucose every day.

93ae9f2d376e5426e891a9b58d8302fa

(2936)

on December 18, 2011
at 11:11 PM

Calories in/calories out, eh? I thought we were over that.

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 19, 2011
at 01:42 AM

"less balanced comments" that's funny considering every comment I post is: it depends, we don't know, and moderation.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 19, 2011
at 12:54 PM

Your comments suggest you either have completely missed the point or are deliberately rejecting it, without any good reason.

24df4e0d0e7ce98963d4641fae1a60e5

on December 20, 2011
at 12:52 PM

@April: I think it was KHG who made the statement once that ketones are more efficient only if you don't look at what goes into making them. Perhaps I need to state this differently. If humans were in ketosis 99% of the time during evolution, why do people even have to "adapt" -- we should feel like total lethargic crap eating carbs and our ancestors doing so would not have survived.

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 19, 2011
at 01:42 AM

And for weight loss purposes it is calories in/calories out. Find me an isonitrogenous metabolic ward study that shows the opposite.

24df4e0d0e7ce98963d4641fae1a60e5

on December 19, 2011
at 06:26 PM

@Andy: Perhaps glucose is needed here ;-) Seriously, though, my original post began with the FACT that humans are not carnivores. Compare our physiology to obligate carnivores and this is abundantly clear. Nor are we herbivores ... again compare the physiology. Feed an herbivore animal flesh and it's not a good scene. What I'm saying is that we have a marvelous flexible digestive and metabolic system to operate on a mixed diet. Why would we have these if we weren't intended to? The rhetorical questions are not 2 appeal 2 a very low denominator, but to get some to question 4 themselves.

24df4e0d0e7ce98963d4641fae1a60e5

on December 19, 2011
at 06:53 PM

@Andy: (hate those character limits) As much as I try to back my blog posts with scientific references, I'm limited in time for doing same here. The way I look at it too, unless challenged for "proof" I'll post thoughts. Re: ketones, show me the evidence that the brain prefers ketones to glucose. Epiletics don't count.

Medium avatar

(39821)

on December 19, 2011
at 07:50 PM

Conciliator, Evelyn...ever feel like this on PaleoHacks? : http://i41.tinypic.com/2ajqi3l.gif ?

Cf32992bfa1907147c7cdc451bba9c63

(2890)

on December 19, 2011
at 10:19 PM

Yes. Some days I think everyone on the internet is conspiring to troll me.

24df4e0d0e7ce98963d4641fae1a60e5

on December 19, 2011
at 11:04 PM

@AndyM: Perhaps you can provide me with the names and email addresses of those 'authorities' I need to contact who would disagree with my "pandering misconception" that humans are not carnivores and this is likely why most do not do well with extreme carb restriction. I'm not here to debate specifics of what is best for different tissues, but IF ketones are best for the heart, my original rhetorical question stands.

24df4e0d0e7ce98963d4641fae1a60e5

on December 19, 2011
at 12:16 PM

@Huey: Do you really believe that excess dietary carb gets stored as body fat but excess dietary fat does not?

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 19, 2011
at 07:08 PM

I was thinking of the heart rather than the brain. And we weren't 'intended' to operate on anything. Clearly there has been an advantage to remaining omnivorous in terms of our adaptability, however it also seems reasonable that we would have a flexible diet if you consider our evolution from a plant-based diet to increasing consumption of meat. We may not have all the answers, but why try and paint a particular picture by phrasing questions as if we do?

24df4e0d0e7ce98963d4641fae1a60e5

on December 20, 2011
at 12:45 PM

@AndyM: You're the one twisting things about and I have no patience for that. VLC/ZC = essentially carnivore diet. Humans are not carnivores. @Everyone else: My point is not that different cells have preference for different things, it's that when glucose is around, all cells seem to use it, when it's scarce, then they use ketones. IF ketones were biochemically better, why wouldn't the ketotic humans have a survival advantage?

24df4e0d0e7ce98963d4641fae1a60e5

on December 19, 2011
at 12:38 PM

I see we have CDS sufferers that need to watch this BBC Program. It's 5 parts on YouTube, I've linked to them all here: http://carbsanity.blogspot.com/2011/01/must-see-tv-for-those-suffering-from.html

Medium avatar

(10663)

on December 20, 2011
at 03:46 AM

And this article: http://www.annualreviews.org/doi/abs/10.1146/annurev.ph.36.030174.002213 which claims that ketones are the preferred energy source for highly active tissues such as the heart and muscle. On low carb-diets, ketones have a glucoprotective effect, in that they are capable of accommodating a wide range of metabolic demands to sustain body functions and health while not using, and thus sparing, protein from lean muscle tissue.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 19, 2011
at 11:47 PM

Try taking a deep breath and reading it again. If you really think it's just me that's come up with the idea that the heart uses ketones more efficiently then argue with Travis about it, don't conflate the issues, and if you don't want to debate the issues quite chucking them out there. Your original rhetoric was so simplistic and reductionist as to not stand in any event. Is this really the level of your reasoning in everything you post?

Medium avatar

(10663)

on December 20, 2011
at 03:39 AM

Has anyone read this article from the NY Times by Taubes who says that "the heart and brain run 25% more efficiently on ketones than on blood sugar." http://www.eabbassi.ir/what%20if%20its%20all%20been%20a%20big%20fat%20lie.pdf (found on page 9)

Cc69a51b427eaad36251cce9dcca4d3a

(1074)

on December 24, 2012
at 07:27 AM

lol such a troll comment. its ironic cuz carbsane probably needs a true ZC diet more than anyone

6
Cf32992bfa1907147c7cdc451bba9c63

on December 18, 2011
at 07:17 PM

To expand on my original position, after you hit sufficient protein and EFA, I think the ratio of carbs to protein depends.

Ketosis can have a strong appetite bluting effect, and lowered carbs certainly seem to lead to many people feeling wired (at least in the short term).

As you get leaner, insulin sensitivity will increase and you will be able to handle more carbs and probably do better with more carbs.

Similarly, with increasing activity (especially high intensity), carbs will likely make you feel and perform better.

There is a huge genetic component to this as well.

So, like most things, the ratio of carbs:fat one feels best on is a bell curve influenced by many factors. People who give narrow responses don't understand the breadth of factors at play here. So experiment, find out what works best for you.

I think most people will be surprised that moderate amounts of each nutrient are close to ideal (20-50% carbs, 20-50% fat, 20-40% protein). As much as we like to think otherwise, we are not snow flakes, we are in the majority the majority of the time.

List of factors that should determine how you feel for a carb intake (and therefore, your carb:fat ratio)

  1. Leanness (lower bodyfat -> higher insulin sensitivity, lower circulating leptin)
  2. Activity (activity -> higher insulin sensitivity, higher cAMP, higher catecholamines)
  3. Genetics (some people never feel good in ketosis)
  4. How long you have been in ketosis (the brain takes a few weeks to become keto-adapted)
  5. Electrolytes (potassium, Mg, Zn all seem to help brain fog from ketosis)
  6. Meal frequency (more, smaller meals seem to lend themselves better to high carb. That is, I would not recommend two meals a day on high carb, gastric emptying would be too high).
  7. Protein intake (higher protein would lead to less ketosis. E.g. 80/20 fat protein is much more ketone heavy than 50/50.)

Another fun fact: low liver glycogen levels can send a signal to the brain inducing hunger. So although ketosis does blunt hunger for some, having enough carbs to keep liver glycogen not empty seems to help some people.

1
Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 18, 2011
at 10:40 PM

Fundamentally, I don't think anything can be guaranteed to work if you've spent a substantial period of your life - particular growing up - doing something else. I think a lot of people would consider they did much better on low carb if they'd never had access to higher carb. But whatever you're doing, there are a whole range of factors that need to be handled differently. You can't just simply change the foods and not adopt different eating and exercise habits and expect it to work the same.

F0e558010a2ecb31fa37b7c491596b8e

(3850)

on December 19, 2011
at 05:35 PM

My personal experience has been the exact opposite. I ate a SAD high carb diet for most of my life and progressed from a healthy kid, to a moderately unhealthy overweight young-adult, to a very unhealthy overweight adult. Eating lower carb, and being in ketosis (which I have done on and off for a decade) is the best and healthiest I've felt in my life.

Dfada6fe4982ab3b7557172f20632da8

(5332)

on December 20, 2011
at 12:41 AM

Yes, your personal experience is a counter-example, but you were asking about other people in general.

F0e558010a2ecb31fa37b7c491596b8e

(3850)

on December 19, 2011
at 05:35 PM

Had I grown up eating a more moderate (lower, healthy carb) diet, I may be able to exist happily on that for the duration, but I feel like my metabolism has been do damaged during my first 30 years that I have no choice but to go down the opposite path to what brought me here.

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