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  • #16
    Huh?

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    • #17
      Originally posted by ChocoTaco369 View Post
      It does not mean metabolic advantage.

      Protein has a higher burn rate than carbohydrate or fat. It is difficult to metabolize, and it takes more energy to do so. However, people on low carbohydrate diets have slower metabolisms than people on high carbohydrate diets assuming equal protein content and you maintain proper saturated:unsaturated fat ratios. The reason why is people with low carbohydrate intake have a slower thyroid and their mitochondria puts out less CO2, which means impaired cellular respiration.

      Gluconeogenesis is an emergency mechanism. Glucose is so essential to your body that it will devour its own muscle and connective tissue to get it. It is far more essential than dietary fat. The brain comes first, and even in full blown ketosis, the body requires more sugar than fat each day. It'll get it any way it has to, even if it is has to suck it from your other organs.

      Your body does not want to be in gluconeogensis for prolonged periods of time. The end result may be hypothyroidism, adrenal fatigue and the diseases of society that come along with metabolic failure (i.e. cancer). The Inuits are probably the most notable low carbohydrate society, and they are well-known for their rapid aging.
      Your body only needs 30-50g of glucose per day either from carbs or broken down from protein, and only the brain needs glucose to begin with.

      Your body will easily burn 150g of fat per day for the rest of your body that can use fatty acids and ketones for energy.

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      • #18
        Sigh ...

        If anyone wants a really good book on metabolism, this one is hard to beat: Metabolic Regulation: A Human Perspective

        If you read through that book, and this means you Choco, you may come across some interesting facts regarding lactate and pyruvate and obligate glycolytic cells and tissues.

        When we talk of "obligate glycolitic" tissues, we are using the word obligate in the sense of obligation, or something that is mandatory, that one must do. Therefore, obligate glycolytic tissues and cells are forced to use glycolysis as their energy source. Normally, the end product of glycolysis, pyruvate, enters the electron transport chain where it generates a whole lot more additional ATP than glycolysis alone. The electron transport chain is part of mitochondrial membranes, so, if you want to use the electron transport chain, you'd better have a whole bunch of mitochondria.

        Obligate glycolytic cells do not possess mitochondria so they lack the physical structures necessary to further oxidize pyruvate. Now, as mentioned, the end product of glycolysis is pyruvate and or lactate, both of which are water soluble, that is, they dissolve and circulate in plasma. This is important because while we can measure quantities of lactate in the blood, we do not observe any meaningful levels of pyruvate or lactate in the urine, or in other words, we do not excrete these substances, rather we recycle them. This recycling is ... gluconeogenesis.

        So, every second of every day that you are alive, every single red blood cell you possess is merrily churning out glycolytic end products which are carried in the plasma to the liver where they are recycled back into glucose which is then shipped back into the blood stream, or stashed away as glycogen in order to keep those busy little blood cells alive. Gluconeogenesis at its finest. To characterize a process that is ongoing every second of every day in the vast majority of higher order organisms, and certainly in all mammals, as "an emergency mechanism" is nothing but delusional hysteria, or to be kind, represents a gross misunderstanding of the fundamentals of the process.

        Furthermore, as to "your body does not want to be in gluconeogensis for prolonged periods of time." You're right, whereas a want is a desire, for your body, gluconeogenesis is a _need_ : a condition necessary for sustaining life.

        As far as CO2 production is concerned ... man, Taco, you must make this stuff up as you go along, don't you?

        Most organic compounds such as fatty acids, glycerol, carbohydrates and amino acids that have undergone deamination ( removal of the NH3, or amine, group ) have the general complete oxidation formula :

        CxHyOz + (x + y/4 - z/2) O2 ---> x CO2 + (y/2) H2O

        So the only thing governing CO2 production is the number of carbons in the molecule undergoing oxidation, not lower thyroid activity impacting mitochondrial energy output. Armed with this equation we can predict that the complete oxidation of glucose will yield 6 CO2 molecules, palmitic acid 16, oleic acid 18, alanine ( an amino acid ) 3. The magic is all in the substrate. If all we're after is increasing CO2 output, oxidizing dietary fat is the way to go. Want to minimize CO2 production? Then oxidize some specific short chain amino acids like alanine.

        Finally, regarding the study that started this all, it is not very controversial, pretty standard stuff. It is well known that ingested protein stimulates protein synthesis, some of it is directly oxidized, and some amino acids can participate in gluconeogenesis. As there is a limit to how much protein synthesis can occur over a given time frame, when you overeat protein, where overeating merely means exceeding your capacity for protein synthesis, increasing amounts will be shunted into the oxidation and gluconeogenesis pathways.

        This study merely set out to confirm that the high thermic effect of protein was due in large part to the relative inefficiency in the gluconeogenetic pathway. Which they effectively confirmed. Move along ... nothing to see here.

        -PK
        Last edited by pklopp; 05-17-2013, 07:37 AM.
        My blog : cogitoergoedo.com

        Interested in Intermittent Fasting? This might help: part 1, part 2, part 3.

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        • #19
          Pssst...

          I've said this before and I'll say this again...
          I'm HFLC, I also have a brain condition and take a medication that "can" cause some of the conditions that Choco thinks that HFLC can cause such as low CO2. So I get tested regularly for CO2 and other markers, and I've had my every other test under the sun performed because I'm a special goddam snowflake... the vampires take blood; they test for all the things.


          My CO2 is always in the med-high normal range. Not low.
          My cortisol has never been elevated.

          HFLC helps me control that brain condition and is recommended by my Neurologist as perfectly safe... the doctor does not recognize that HFLC is a cause of any of the things that Choco suggests.
          I'm under watch and need to be regularly tested because of the medication I have to take. No other reason.
          Last edited by cori93437; 05-16-2013, 09:41 PM.
          “You have your way. I have my way. As for the right way, the correct way, and the only way, it does not exist.”
          ~Friedrich Nietzsche
          And that's why I'm here eating HFLC Primal/Paleo.

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          • #20
            pklopp:

            If you're only looking at the carbons in the molecule undergoing oxidation, the ratio of hydrogen to oxygen in carbs is equal to water. Lipids(fat) contain a lot less oxygen atoms in proportion to hydrogen and carbon, ergo, when fat is degraded it requires a lot more oxygen to oxidize fat to water and co2. So, how exactly, is fat better for producing co2? By wasting more of it? I'm not understanding your logic.
            Make America Great Again

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            • #21
              He did not say that fat was "better" at producing CO2 but that fat oxidation yields more CO2 by simply looking at the number of carbon atoms and chemical equation above. I don't see a logical problem here.

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              • #22
                Originally posted by dkJames View Post
                He did not say that fat was "better" at producing CO2 but that fat oxidation yields more CO2 by simply looking at the number of carbon atoms and chemical equation above. I don't see a logical problem here.
                I read this: "If all we're after is increasing CO2 output, oxidizing dietary fat is the way to go." as exactly what I said. It's incomplete and misleading.

                RQ is the respiratory quotient. His equation represents carbon, oxygen, and hydrogen metabolism. But, for specific macronutrients, it breaks down like this.

                c6h12o6 + 6 O2 -> 6 CO2 + 6 H2O the gas exchanged is equal so... rq = 6 co2 / 6 o2 = 1.0

                If we take his 16 co2 it would leave fat with an RQ of 0.696 round up to 0.7

                c16h32o2 + 23 o2-> 16 co2 + 16 h20 16 co2 / 23 o2 = 0.696

                Fat also oxidizes much slower due to this fact.
                Make America Great Again

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                • #23
                  Originally posted by Derpamix View Post
                  I read this: "If all we're after is increasing CO2 output, oxidizing dietary fat is the way to go." as exactly what I said. It's incomplete and misleading.

                  RQ is the respiratory quotient. His equation represents carbon, oxygen, and hydrogen metabolism. But, for specific macronutrients, it breaks down like this.

                  c6h12o6 + 6 O2 -> 6 CO2 + 6 H2O the gas exchanged is equal so... rq = 6 co2 / 6 o2 = 1.0

                  If we take his 16 co2 it would leave fat with an RQ of 0.696 round up to 0.7

                  c16h32o2 + 23 o2-> 16 co2 + 16 h20 16 co2 / 23 o2 = 0.696

                  Fat also oxidizes much slower due to this fact.
                  Yes, that is what is measured when people are on ketogenic diets: around 0.7. On highly glycemic, you get close to 1. So your numbers are consistent with the measurements.

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                  • #24
                    Originally posted by Derpamix View Post
                    I read this: "If all we're after is increasing CO2 output, oxidizing dietary fat is the way to go." as exactly what I said. It's incomplete and misleading.

                    RQ is the respiratory quotient. His equation represents carbon, oxygen, and hydrogen metabolism. But, for specific macronutrients, it breaks down like this.

                    c6h12o6 + 6 O2 -> 6 CO2 + 6 H2O the gas exchanged is equal so... rq = 6 co2 / 6 o2 = 1.0

                    If we take his 16 co2 it would leave fat with an RQ of 0.696 round up to 0.7

                    c16h32o2 + 23 o2-> 16 co2 + 16 h20 16 co2 / 23 o2 = 0.696

                    Fat also oxidizes much slower due to this fact.
                    So ... respiratory quotient is a ratio, as you show above, CO2 to O2. And you are correct, an RQ of about 0.7 represents fat oxidation, whereas a respiratory quotient of 1.0 represents CHO oxidation. And you are also correct in your observation that 0.7 is less than 1.0. The wheels fall off when you fail to (or refuse to?) recognize that 6CO2 molecules is almost three times less than 16CO2. The fact that the oxidation of palmitate ( in this case ) takes more exogenous oxygen is irrelevant and ultimately a result of stoichiometry, not "my equation."

                    Again, I stand by my original assertion ... "if all you care about is CO2 production", all you need to do is manipulate the carbon chain length of whatever it is that you are oxidizing. If you want to increase it, oxidize something with lots of carbon. If you want to decrease it, oxidize something with less carbon. The carbon is, after all, the source of the C in the CO2. Please take the time to digest the fact that by the very definition of RQ, since you are actually comparing carbon dioxide production to oxygen consumption, you obviously care about both, and that violates my stated condition that "all you care about is CO2 production."

                    This was in direct response to Choco's unsubstantiated statements regarding CO2 and "impaired mitochondrial respiration" which, as you can now see by crunching the numbers yourself, is pure drivel. The only way that I can see for that to be incomplete and misleading is for one to go and strip away all the context when quoting me.

                    As far as the rates of oxidation of CHO relative to fats is concerned ... the oxidation equations as presented generally relate to pure combustion. That energy is given off as heat, whereas the biochemical pathways that actually generate energy for cells harness the energy of oxidation to phosphorylate ADP, and they do so in a very controlled manner. You can't go around releasing combustion level energy within a cell and expect that cell to remain viable.

                    While I'm not sure about this, I suspect that your comments relating to fats oxidizing more slowly than carbohydrates stem from confusion regarding substrate level vs. oxidative phosphorylation, which relates to how cells generate ATP. In the case of substrate level phosphorylation, this pathway is only available to glucose and it is very fast, and rather inefficient. For every molecule of glucose that undergoes substrate level phosphorylation, you very quickly generate two ATP molecules and two pyruvate molecules. The chief advantages here are that this is a very quick process, it occurs in the cellular cytoplasm, and requires zero oxygen. The drawback, to reiterate, is the inefficiency of the process vis a vis ATP production.

                    Oxidative phosphorylation, on the other hand, is orders of magnitude more efficient at ATP production, yielding about 30 ATP molecules per glucose, and roughly three times that amount for long chain fatty acids. Oxidative phosphorylation is quite slow relative to substrate level phosphorylation, it takes place in mitochondria ( which means your cells must have them, and not all your cells do ), and as the name plainly suggests, it requires oxygen, hence the oxidative label.

                    Both fats and glucose can enter the oxidative phosphorylation pathway, glucose via its pyruvate metabolite, and fats via beta oxidation, and they both provide intermediate metabolites for the TCA cycle and the electron transport chain. So, apart from the relatively few chemical reactions that initiate oxidative phosphorylation, the remainder of the reactions involved are indistinguishable for fats and carbohydrates.

                    Now, it is possible that I have misunderstood you and that you were actually intending to enter into a discussion with me over the kinetics of the enzymes that catalyze the initial distinct pathways of fats and CHO, but I considered that a fairly low probability outcome. Nevertheless, since that probability is not zero, if that is the discussion you want to have, I'll leave it up to you to come up with the initial data regarding the relative kinetics of the enzymes that catalyze the various oxidative phosporylation pathways.

                    -PK
                    My blog : cogitoergoedo.com

                    Interested in Intermittent Fasting? This might help: part 1, part 2, part 3.

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                    • #25
                      I always wonder during these conversations... how many people involved in them have ever been Keto while also being regularly tested for things like CO2 levels?

                      Oh. Me.
                      ...because I take a medication that can mess up my CO2 levels. (My neurologist says being Keto has nothing to do with it.)

                      Yeah.
                      Always mid-high normal range.

                      I've also had my cortisol tested because of long term medication use and chronic disease... normal (despite "Keto").
                      Though my doc says keto is also no reason to worry about that either.


                      Always the same scare tactics. It's ridiculous.
                      Some people are so biased it's painful.
                      It's almost as bad as Choco's "only cold water fish are fatty" argument.
                      “You have your way. I have my way. As for the right way, the correct way, and the only way, it does not exist.”
                      ~Friedrich Nietzsche
                      And that's why I'm here eating HFLC Primal/Paleo.

                      Comment


                      • #26
                        Originally posted by cori93437 View Post
                        It's almost as bad as Choco's "only cold water fish are fatty" argument.
                        But is the fat rendered? That is the question.

                        But seriously, thanks, PK for another well written and researched post.

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                        • #27
                          The reason why fats produce more ATP coincides with the fact it oxidizes much slower. Fats have to be transported from fat cell tissue to metabolize in form of vesicles, which are taken up through endocytosis and degraded into fatty acids, then finally have to be converted into acetyl CoA before entering beta oxidation. Also, the fact fat contains an enormous amount of carbons and have to have already circulating oxygen in the cells in order to couple further slows this process. Also, fat oxidation produces huge amounts of water, which can burden the cells and respiratory system and cause lactic acid build up to take the place of the missing oxygen for energy, which shortens the ATP produced.

                          Have you ever left a banana out and watched how fast it browns?

                          The pathway for glucose -> pyruvate -> acetyl CoA is much simpler and preferred as principal source for acetyl CoA and mitochondrial function. For example: with each cycle, a fatty acid is shortened by two carbons while oxidized and its energy captured by the reduced energy carriers nadh and fadh2. At the end of the four reactions, one acetyl CoA 2 carbon unit is released from the end of the fatty acid, going through another round of beta oxidation, continuing to shorten even chain fatty acids until they are entirely converted to acetyl CoA. Eventually you're left with an odd number of carbons in the acyl chain, which cannot enter another round of beta oxidation.

                          This is typically why we store fat as energy, as it's much more dense, oxidizes slower, and is too complex and burdening to use as a main source of energy.

                          I'll also assume you're talking about short chained fatty acids, as very long chain fatty acids cannot be used by the mitochondria and produce no ATP(peroxisome beta oxidation)
                          Last edited by Derpamix; 06-01-2013, 08:03 PM.
                          Make America Great Again

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                          • #28
                            Originally posted by cori93437 View Post
                            I always wonder during these conversations... how many people involved in them have ever been Keto while also being regularly tested for things like CO2 levels?

                            Oh. Me.
                            ...because I take a medication that can mess up my CO2 levels. (My neurologist says being Keto has nothing to do with it.)

                            Yeah.
                            Always mid-high normal range.

                            I've also had my cortisol tested because of long term medication use and chronic disease... normal (despite "Keto").
                            Though my doc says keto is also no reason to worry about that either.


                            Always the same scare tactics. It's ridiculous.
                            Some people are so biased it's painful.
                            It's almost as bad as Choco's "only cold water fish are fatty" argument.
                            I think that, beta oxidation of short chain fatty acids is sufficient enough to support metabolism, co2, and the mitochondria, it's just never the preferred choice. It's also that, most people have far too much circulating PUFA, which not only compromises this, but is vastly harmful, as liberating free fatty acids dictates. It causes problems with fat metabolism as well as glucose.

                            Also, too many variables, no one person's anecdotal experience amounts to anything, your problem is probably just what was said above, and a compromised glucose metabolism. But, whatever supports your health and works for you, you're the only one who really knows. I know, for me personally, VLC was absolutely destructive to my health in all ways.
                            Last edited by Derpamix; 06-01-2013, 08:20 PM.
                            Make America Great Again

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                            • #29
                              Oh, well I guess if bananas turn brown when left out in hot weather, that means VLC is a bad diet.

                              Cori, why didn't anyone tell us about this sooner? <passes the bread to Cori>

                              But seriously Derp. Nobody is pro-PUFA around here so you can quit fighting that strawman.

                              And, "This is typically why we store fat as energy, as it's much more dense, oxidizes slower, and is too complex and burdening to use as a main source of energy." (/Derpquote)

                              Could easily be re-written as, "We store fat as energy as it's much more dense, oxidizes slower, and is therefor the perfect fuel to use as a main energy source while reserving glucose for infrequent short burst activities such as running away from a saber toothed tiger."

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                              • #30
                                Originally posted by Paleobird View Post
                                Oh, well I guess if bananas turn brown when left out in hot weather, that means VLC is a bad diet.

                                Cori, why didn't anyone tell us about this sooner? <passes the bread to Cori>

                                But seriously Derp. Nobody is pro-PUFA around here so you can quit fighting that strawman.

                                And, "This is typically why we store fat as energy, as it's much more dense, oxidizes slower, and is too complex and burdening to use as a main source of energy." (/Derpquote)

                                Could easily be re-written as, "We store fat as energy as it's much more dense, oxidizes slower, and is therefor the perfect fuel to use as a main energy source while reserving glucose for infrequent short burst activities such as running away from a saber toothed tiger."
                                What are you talking about? -_- Bananas brown because they oxidize faster as referenced in my equation above. It has nothing to do with VLC. And bread is already oxidized. It was just about the equation and compositions.

                                Seriously, why are you cherry picking useless abstracts when I'm not even addressing you?
                                Make America Great Again

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