~mina~
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Cyclical Ketogenic Diets Part 1http://low-carb.org/lylemcd/cyclic1.htm
Lyle McDonald 1996 article
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Dean
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Mina,
This article is 12 years old. Do you have something more recent? This info is so outdated. If the current stuff is the same, wow, that's spooky.
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~mina~
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I was hoping to prompt a discussion 
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Dean
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Yah, and I was wanting to comment on a lot of the things in this article, but, I didn't wanna waste my time if this has been radically altered since 1996. If not, then, look out. There is so much fat phobia and other overturned ideas in this article that I wasn't sure if the position he takes has been changed since. He assumes our "normal" metabolism is based on carbs, and that an "unnatural" one is based on fat/ketones. Hello?  Then, there's the free radical deal being caused by fat metabolism. Uh, don't think so. There are many things that I agree with, but, many that I just don't.
Anyway, I guess I can critique this 12 year old article... just for fun. 
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Dean
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Well, you asked for it, Mina. 
| Quote: | Unfortunately, it is difficult to draw any absolute conclusions about this
approach from article written about it as the groups involved in the debate
invariably have some vested financial interest in either promoting or
decrying the approach. |
 You said it, Lyle.
| Quote: | Most aerobic tissues, including the brain, skeletal
muscle, and the heart can oxidize KB's for fuel (8). Under normal blood
sugar conditions, glucose is the preferred fuel in the brain, muscles and
heart. Under these conditions the rate of ketone body utilization by
tissue depends in part on their concentration. Under normal conditions, KB
metabolism is minimal, perhaps 1-2% of total energy expenditure. |
What is "normal" about humans consuming carbs? Nothing. We evolved for millions of years eating virtually zero. How can it be normal? The fact that most aerobic tissues (those that have cells with mitochondria) can use KB and FFA for energy production should give us a clue to this fact. Blood cells are the ones that need glucose, because, technically, they are "outside" our other tissue, and are involved in a delivery system. We (and all land animals) first evolved as creatures that were swimming through water, picking up nutrients from around them. Then, land based animals evolved to incorporate this system into their bodies, in the form of a blood "stream" that would deliver the nutrients to the tissues (which make up organs, muscles, and such). The cells that make up this tissue have mitochondria and are supposed to use FFAs and KBs as substrates to produce the ATP they need. That is what is normal. Glucose is made by the liver to take care of the ancient cells (lacking mitochondria) in this blood stream. Let's get real. We were not eating carbs to get this glucose, until very recently.
| Quote: | The formation of KB's and utilization of fuel is ultimately controlled by
the circulating levels of insulin and glucagon. Insulin is a hormone
released from the pancreas in response to eating carbohydrates. Glucagon
is insulin's antagonistic hormone and is only present when insulin levels
fall to quite low levels. In the liver, high glucagon levels direct FFA
away from TG synthesis and towards beta-oxidation. Glucagon also activates
adipose tissue lipase which activates lipolysis. Glucagon's ketogenic and
lipolytic effects are inactivated by even small amounts of insulin. To
achieve sufficient glucagon concentrations for increased
ketogenesis/lipolysis, blood glucose levels must drop to around 50-60 mg/dl
and insulin must drop almost to zero. This drop in insulin can occur with
complete fasting, exercise, or by simply restricting carbohydrate intake to
below 30 grams per day. Within about 3 days of carbohydrate restriction,
blood glucose will fall below 60 mg/dl, insulin levels will drop to zero
and glucagon levels will increase causing an increase in KB formation.
With exercise training, ketogenesis should occur more quickly and ketosis
established. (2) |
Sound familiar? This is what Bear always said, and everyone gave him so much grief about it! Yes, with insulin low, and normal glucagon levels present, FFA will be directed away from TG synthesis (body fat accumulation) and towards beta-oxidation (burning the FFAs and KBs for fuel by the vast majority of our cells). However, even small amounts of insulin can prevent this.
As Kristelle keeps trying to tell everybody, perhaps you need to go as close to ZC as possible to get this keto-adaptation to take place. After a lifetime of carb consumption, it is very possible that this is exactly what people must do, but, usually cannot, because of such strong acculturation. Then, they attack ZC as something that doesn't work. 
| Quote: | Ketosis (defined as the buildup of the KB's in the bloodstream) will occur
under several conditions including: fasting, after prolonged exercise, and
when a high fat diet is consumed. (7,8,15).
Once ketosis is established (i.e. when ketone concentration in the blood
is higher than glucose concentration), ketones will become the preferred
fuel by all three tissues providing up to 75% of the fuel utilized (7).
The brain, which normally utilizes glucose exclusively for fuel will, after
a period of 2 to 3 weeks, switch almost exclusively to using KB's for fuel
(1, 6, 15). |
What he is saying is correct, and, it's what Bear was saying. The bodies need for glucose will go way down, and gluconeogenesis of protein will go way down. Bear said, and I strongly believe, as does Lyle, that GNG does NOT occur that often, and therefore muscle does not waste away on a ZC diet, nor is all the protein we eat converted to glucose, as some say it is.
| Quote: | Food can be rated as either ketogenic or anti-ketogenic dependent on their
conversion to glucose in the body. Dietary fats are the most ketogenic
item, converting to glucose with only 10% efficiency. Proteins are in the
middle, converting to glucose with about 58% efficiency (this is due to the
fact that some dietary amino acids are ketogenic in nature, meaning that
they convert to ketones, and others are glucogenic, meaning that they
convert to glucose) (2). Dietary carbohydrates convert to blood sugar with
100% efficiency making them completely anti-ketogenic in nature. |
Just because protein CAN be converted to glucose with 58% efficiency does NOT mean it always is. The bodies NEED for glucose is ALWAYS what determines the rate of GNG, and, that need is greatly reduced on a ZC diet, once we fully keto-adapt. What is so fricken hard to understand about that? Hard to do perhaps, but, to understand? 
| Quote: | The presence of ketosis through whatever means implies two things (15):
1. that lipid energy metabolism has been activated
2. that the entire pathway of lipid degradation is intact.
Normally, there is fairly tight control on the production of KB's. Except
in pathological conditions such as diabetes, excess ketones will simply be
excreted in the urine (1). This allows an individual to check for the
presence and urinary concentration of ketones by utilizing Ketostix.
And, those ketones in the urine will go down as we become more keto-adapted.
Establishment of ketosis, even in the short term, has the effect of
increasing the body's ability to utilize fat for fuel. After adaptation to
ketosis, there is a decrease in fasting RQ (an indicator of relative fuel
metabolism with lower values indication greater reliance on fat metabolism
versus carbohydrate metabolism) (7). Also, there is a decrease in glucose
oxidation during ketogenic diets as KB's are providing much of the body's
energy needs (18). Additionally, adaptation to a ketogenic diet increases
fat oxidation during exercise even in trained individuals (14, 17). |
Just what Bear said. We don't need carbs for exercise, do we jeff? BTW, that 17 is a reference to Phinney. Go figure.
| Quote: | One point of contention regarding ketogenic diets is the supposed protein
sparing effect when compared to a eucaloric diet with a high carbohydrate
intake. Due to methodological differences, some studies have found a
decrease in protein utilization while others have found an increase (8).
However, available data seems to support the idea that ketosis spares
protein from being used for energy. Since there is essentially an
unlimited supply of fat which can be converted to ketones, and since
ketones can be used by all oxidative tissues, there should be little need
to oxidize protein to generate glucose through gluconeogenesis. There is
an obligatory protein requirement which must be met of about 30 grams per
day. And, to be safe, an intake of 60-75 grams of protein is recommended
(7). |
Again, saying the same thing that Bear said. We won't lose muscle mass, because our cells won't need to use protein or carbs, when there is plenty of fat and ketones to use, provided we have allowed for the necessary enzyme switch out (adaptation) to occur, which does take time (and dedication to stick to a VLC/ZC diet).
| Quote: | Additionally, a low carbohydrate intake will allow for overall greater
lipolysis and free glycerol release when compared to either high
carbohydrate or normal diets (7, 12). This is mediated in part by the lack
of insulin, which has a lipolysis blocking action even at low
concentrations as well as increases in other lipolytic hormones such as
growth hormone, glucagon, the catecholamines, and glucocorticoids. (7)
Additionally, growth hormone levels increase on low carb diets which will
further help to prevent the inevitable protein losses which occur when
calories are restricted (2, 7). |
With growth hormone and glucagon up, because of insulin being down, protein losses are LESS than on a high carb diet. What does that tell us? Does that sound like glucose metabolism by cells that don't even prefer it is normal? Or does it tell us that glucose is burned up by these cells to get it OUT of the blood stream. Too much glucose and insulin in the blood is dangerous, people. It really is. And, during this emergency burning our oxidative cells go through, free radicals are released. Not good for the cells at all. Carbs are killers, anyway you look at it. Oh, they taste real good, but, they are not good for us. They really aren't.
| Quote: | This suggests that the lowering of insulin, and the resultant
hormonal mileu created may optimize the oxidation of fat when fat loss is
the goal. However, as many individuals find completely adequate success
with a less stringent diet, this type of extreme approach is likely not
warranted for everyone. Additionally, a similar hormonal mileu (i.e.
lowering of insulin, etc.) can occur under normal dietary conditions
through various means. A replacement of higher glycemic index
carbohydrates with lower GI carbs will lower basal insulin levels as will a
high fiber intake. Cardiovascular exercise done first thing in the morning
before any calories are consumed may create a similar hormonal picture due
to the lowering of blood glucose after an 8 hour fast. Additionally, the
performance of cardiovascular exercise following high intensity resistance
training should also allow for greater fat utilization due to lowered blood
glucose and insulin levels. |
This idea that "many individuals find completely adequate success with a less stringent diet" is troubling. What is "success"? Losing weight? At what cost? Carbs are dangerous to those who are overweight, underweight, or at the right weight. They are not good for us. Period. While we might be able to "handle" them, it is not advisable to use them. Easier said than done, I know, believe me, but, that doesn't change the reality of the damage being done.
| Quote: | However, we have not yet discussed the most unique feature of the
cyclical ketogenic which is the high carbohydrate phase on the weekends.
The validation of the weekend carb-up is the point upon which the cyclical
ketogenic diet ultimately hinges. Unfortunately, direct data on healthy
athletes is sorely lacking and only inference can be drawn from other data.
The problem with all fat loss diets is the inevitable loss of lean body
mass (i.e. muscle) which will occur. This leads to a loss of muscle tissue
and a slowing of metabolism making weight regain highly likely. While
ketogenic diets may limit muscle protein loss more so than high
carbohydrate diets, the loss of some muscle will occur. The weekend
carb-up, in addition to refilling muscle glycogen stores for the next
week's training, may also have the potential to stimulate anabolism and
rebuild some if not all of the lost muscle tissue. What is not understood
is why the period of high carbohydrate intake does not undo the metabolic
adaptations to the ketosis is established during the week. It seems
possible that, for the same reason it takes several weeks to days for the
body to adapt to a ketogenic diet, a similar amount of time may be required
to de-adapt or, rather, readapt to normal carbohydrate metabolism. This
area requires more direct study before any conclusions can or should be
drawn. |
So, for some possible anabolic response, we ingest mucho carbs every weekend? This is my biggest problem with this CKD stuff. It's dangerous. On a cellular level, it's dangerous.
| Quote: | With the consumption of a normal carbohydrate adequate diet, muscle
carbohydrate stores should remain filled. Under normal circumstances, the
muscles contain approximately 350 grams. With glycogen depletion caused by
exhaustive exercise followed by a high carbohydrate intake, these levels of
muscle carbohydrate can be nearly doubled (19). |
Here we go with the word "normal" again. Wow, let's double our glucose stores in our muscles! Why not? Let's force our muscles to suck sugar out of our blood stream for sheer survival. We'd be dead real quick if we didn't have this protective measure in place. This is so crazy, it's hard to find a way to even respond to it.
| Quote: | Under normal dietary conditions, exercise has been shown to increase
insulin sensitivity which increases the muscle's ability to accept insulin
at the receptor level (12) but this increase in insulin sensitivity only
occurs in the muscles trained. The increase seems related to glycogen
depletion in the worked muscles. Additionally, following a low
carbohydrate diet, but not after a high carbohydrate diet, glycogen
synthase activity (the enzyme which stores dietary carbohydrate in the
muscle) is increased further (4). So, all of the pieces are in place. |
In place for what? For a full scale assault on our system? 
| Quote: | By combining a high fat diet, exhaustive exercise training (which should be
performed on Friday prior to beginning the carbohydrate loading period) and
a high carbohydrate intake, glycogen supercompensation can occur. |
Sounds like a horror movie. Glycogen supercompensation. Insanity. Pure insanity. 
We need to let our muscles become adapted to using their normal fuel, which is NOT glucose! That is the only healthy and sane approach.
Anyway, then he goes on to say how all this glucose and water that is getting jammed into our muscles will help hydrate the muscles so they can get some growth back, because of the inevitable degradation of muscle tissue, which is totally normal, but, as he already noted, LESS on VLC/ZC.
| Quote: | For every gram of carbohydrate stored in the muscle, assuming adequate
water intake, 4 grams of water will be stored additionally. With a normal
mixed diet, muscle carbohydrate stores are roughly 350 grams for a person
with 65kg of lean body mass (19). At 4 grams of water per gram of
carbohydrate, this is 1400 grams of water stored in the muscles. With
super compensation to 16 grams per kg lean body mass, 1040 grams of
carbohydrate can potentially be stored which would yield 4160 grams of
water, almost a 3 fold increase. |
Let's super stuff those muscles with sugar, shall we? So good for us.
| Quote: | Recent research supports the idea that muscle protein anabolism may be
regulated by cellular hydration state at least in certain
pathophysiological states like burn trauma. According to this hypothesis,
cellular dehydration sends a proteolytic (protein breakdown) signal to the
cell while cellular hydration (and, presumably super hydration as would
occur with glycogen super compensation) would send a powerful anabolic
signal to the cell (9,10). Along with this, after 3 days on a high fat
diet, the insulin response to a standard glucose load is increased compared
to a high carbohydrate diet (20). Hyperinsulinemia is another stimulus for
anabolism. (3) So, it seems plausible (although direct research is awaited
to support or refute this) that glycogen super compensation, along with the
powerful anabolic signal sent by the almost three fold increase cellular
hydration could rebuild any muscle lost while following a low carbohydrate,
ketogenic diet. What is not understood at this time is why endurance
athletes, performing an identical form of glycogen super compensation do
not see increases in muscle mass. This suggests that the simple act of
carbohydrate restriction and protein breakdown followed by carbohydrate
loading may not independently promote anabolic processes. |
I love how he cites research on burn victims. Yah, I guess most burned tissue is going to respond well to hydration.
He talks about rebuilding muscle that is lost on a ketogenic diet. But, he already said that muscle wasting occurs on any diet. That is normal. If we eat adequate protein, we'll be just fine, Lyle.
| Quote: | Probably the largest side effect reported with ketogenic diets is fatigue,
especially during the initial adaptation to ketone metabolism, especially
in the brain. A recent study found that, during the first week of a
ketogenic diet, performance on tests indicative of mental flexibility were
impaired. These affects abated as the diet was continued (21). |
Brain fog. So what? Take it now, and avoid the cancer and Alzheimer's later!
| Quote: | One question regarding ketogenic diets is the potential effects on blood
lipid profile. Anecdotally, many individuals report an improvement in
blood lipid profile but this author could only find one reference to
cholesterol levels. During 4 weeks of adaptation to a ketogenic diet,
cholesterol levels did increase from 139 to 200. What effects on blood
lipid longer periods of ketosis would have had are currently unknown. (18)
This underscores the absolute need for anyone desiring to try this approach
to monitor blood lipid levels with frequent blood testing. |
Oh my gosh, our cholesterol levels are going up. Better use statins for that!
| Quote: | Unfortunately, no direct research has been done in the last 15 or so years
looking at untoward side effects of the ketogenic diets. While it is
attractive to draw inference from studies of epileptic children, for whom
ketosis appears to control a majority of intractable seizures and who are
kept in deep ketosis for periods of a year or more (5,13), this sub
population may or may not be indicative of the effects of such a diet in
healthy individuals. Additionally, the fact that the diet is abandoned
after that period of time suggests that long term ketosis may have unwanted
effects. Or that long term adaptation to the ketogenic diet is sufficient
to control the seizures without having to maintain the diet. |
Love how he says "no direct research has been done". Who needs research when we evolved on this diet! Hello? Are you a creationist, Lyle?
| Quote: | Additionally, ketogenic diets have shown some promise in the treatment of
certain types of tumors by starving the tumor of glucose while providing
adequate energy substrates in the form of KB's to other tissues (16).
But, as with the subgroup mentioned above, it would be exceedingly
premature to draw inference as to the long term side effects which may
occur with a ketogenic diet from these studies. The longest study on
ketogenic diets found by this researcher in the last 15 years were only 4
weeks in duration. Therefore, it can only be concluded at this time that
long term side effects of ketogenic diets are not currently known.
Considering that many disease states such as coronary artery disease can
take years to manifest themselves, caution must be taken. |
I think we should keep eating sugar and keep our insulin levels up there. It's already been shown that insulin is what damages our arteries. So, carb up, boys and girls!
| Quote: | As with any radical change in diet or food intake, especially one such as
the ketogenic diet which causes extreme changes in the body's biochemistry,
individuals must take care to monitor their health status. Tracking blood
lipid profile and other indicators of heart disease as well as other bodily
functions will help to indicate if any negative effects are occurring in
the body and frequent diagnostic tests are highly recommended.
Additionally, it is currently unknown whether adaptation to long term
ketosis can be reversed without detrimental effects to normal metabolism.
That is to say, it is conceivable that the metabolic effects caused by such
a major dietary change could cause irreversible changes to normal
metabolism. |
Here we go again. It's a "radical" diet. It's our normal diet, Lyle! See, that's the paradigm shift of the Bus. It's what Bear woke many up to. Although, I think many are still in a carb coma, so they're still asleep. Ah, acculturation. We were warned about that little problem, now weren't we?
| Quote: | Some comment should be made is in regards to nutrient intake. Due to the
restrictive nature of ketogenic diets the potential exists for
micronutrient deficiencies. In the studies on ketogenic diets, the
researchers provided supplementation of a multi-vitamin/mineral tablet to
ensure adequate micronutrient intake. It may be advisable for those why
try such a diet independently to supplement with a multi-vitamin/mineral
providing 100% of the RDA. Additionally, since the consumption of nutrient
dense foods such as vegetables is severely restricted during the week,
these foods should be consumed during the carbohydrate loading phase so
that absolute reliance on supplements is not required. |
Yah, "nutrient dense foods such as vegetables". Wow! And here I've been thinking that animal foods are the nutrient dense foods. I need to go buy some rubbish right away! Start rippin' up my intestines.
| Quote: | Another thing that deserves mention is this: the high dietary fat intake
necessitated by the ketogenic diet is such that increased free radical
production could potentially occur. However, this area requires further
direct study before any conclusions can be drawn. As with other potential
health concerns, this further underscores the need for an individual to
closely monitor their health status before and while beginning such a
dietary regime. |
Now, Lyle, how does high dietary fat intake increase free radical production, exactly? That's not what Eades says. Mina has posted many studies that show that this free radical production is a byproduct of glucose metabolism, not fat metabolism. With all the electron transfers going on in the mitochondria to produce ATP, is it any wonder that some of these electrons would go astray during an unnatural, emergency protective procedure, like sucking excess glucose out of the blood and burning it up as quickly as possible? Think about how long it takes to keto-adapt. This has everything to do with enzymes, and enzymes have everything to do with the processes that go on in making ATP via that whole electron transfer thing. To code for new enzymes is not something our cells are gonna do quickly, or even want to get into quickly. There are extremely complex mechanisms involving ribosomes, DNA, RNA, all that good stuff, for the assembly of these polypeptides (proteins... enzymes) for any type of substrate. Now, if our oxidative tissue has to suck sugar out of the blood in an emergency and then burn it up quickly, where is the time to do that necessary enzyme switch out? THAT is why free radicals are produced. Perhaps if one is adapted to burning glucose, and then they go on a VLC diet and start using fat instead, the same thing might happen, and then the researchers are gonna say, "see, free radicals. Must be the fat. Let's get these research subjects back on the carbs right away".
You know, Atkins always said how harmful it was to switch back and forth between high fat and high carb. Eades has said the same thing. This is the biggest reason, trust me. I know you can't ask Robert, but, just ask Dr. Mike.
| Quote: | Normally, there is a negative feedback loop whereby
excess ketones prevent further production. The slight difference in KB
clearance versus KB appearance corresponds to urinary excretion which is
always below 10% of total turnover. (1)
As further evidence, exercise, which is ketogenic in nature, does not
cause the expected increase in KB concentrations so a negative feedback
loop appears also to be present. (6) This suggests that out of control
ketoacidosis should not occur in normal individuals but, again, there is no
real long term data on this aspect of the diet. Regular checks of urinary
KB concentration (utilizing Ketostix), blood glucose (using a glucometer),
and other indicators of potential problems are highly recommended. |
I'm not worried, Lyle. I've never used Ketostix in my life. Our bodies will adapt, and our blood levels of KBs will come down as we start using them, and, our bodies take care of these KB levels through negative feedback loops, anyway, as you say. Get on the Keto Train, Lyle. 
| Quote: | In conclusion, with the available data, the cyclical ketogenic diet may
have merit for certain applications. The carbohydrate restriction coupled
with the induction of ketosis seems to promote a hormonal mileu conducive
to fat loss. The carbohydrate loading process on the weekend is the least
understood (and least researched) aspect of this dietary approach and much
further elucidation of the possible anabolic processes is required before
any definite conclusions can be drawn. The long term health effects in
healthy individuals of this dietary approach are unknown. The only
studies over four weeks in length were conducted on populations which do
not allow extrapolation to healthy individuals. Again, more research is
needed to establish the safety of this dietary approach in the long term.
In the very short term (4 weeks), it seems well tolerated except for the
afforementioned cognitive effects. |
It may appear to be "well tolerated", but, I guarantee it isn't. Not at a cellular level. It is horrible for anyone to carb up. And, what's even more disturbing, is it's supposed to be used by athletes, for muscle building, not weight loss, as some are trying to use it for. And, even if it could be used for weight loss, as much damage as dietary carbs cause, I'd recommend speed before I'd recommend using this method.
| Quote: | Regular blood work (including before commencing the diet to establish a
baseline) as well as regular checks for urinary ketone concentration are
highly recommended. Any metabolic abnormalities occurring in either tests
should be taken as a sign that the dietary approach should be abandoned.
Finally, due to effects on mental clarity during the first few weeks of a
ketogenic diet, this approach is not suitable for individuals involved in a
job or activity requiring high amounts of mental acuity. |
Yah, if you need to think, don't stop eating our "normal" diet of high carbs.
Let's put on our thinking caps and go out for pizza!
Sorry for the cynicism, but, I've heard so much about this CKD crap that I just had to respond.
Thanks for opening up this discussion, Mina. It was sorta fun tearing this article to shreds.
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