Re: Is ketosis really the "backup" system?

Roger Zoul said:

Ignoramus16674 wrote:

:: They say that burning carbs is the "primary" system of getting
:: energy, and burning fat is secondary. I am curious what is the basis
:: for putting one first and another second.

IMO, the basis is nothing more than the fact that the body will burn (use)
carbs first and easier than it will fat. But, note that the body will burn
alcohol before carbs, and alcohol is supposedly toxic to the body. So, it
could be that carbs are toxic too, at least in large amounts.

It's interesting that when you get into the chemistry, ketones
are the only fuel. Both fat and glucose get converted to ketones
before getting burned.

That makes ketones the primary fuel. Fat, carb, protein, all of
those are just secondary sources of the primary fuel. It's about
as valid as calling carbs primary because they are second in line
after acetate/alcohol.

Roger Zoul generously shared with us this little ditty:

Quoted message said:

Ignoramus16674 said:

Quoted message said:

They say that burning carbs is the "primary" system of getting
energy, and burning fat is secondary. I am curious what is the basis
for putting one first and another second.

IMO, the basis is nothing more than the fact that the body will burn
(use) carbs first and easier than it will fat. But, note that the
body will burn alcohol before carbs, and alcohol is supposedly toxic
to the body. So, it could be that carbs are toxic too, at least in
large amounts.

Very good point. Gee, I wonder why dieticians/nutritionists never bring
*that* one up?
--
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Doug Freyburger said:

It's interesting that when you get into the chemistry, ketones
are the only fuel. Both fat and glucose get converted to ketones
before getting burned.

That's incorrect. The body uses both FFA and glucose without
going through ketone production.

If people really want to understand the chemistry of metabolism
I've found a very good site -- though it is a bit technical for
most. Just push through it and over time the you'll start to
have a better understanding of how the body uses fuel.

The general site:
http://www.indstate.edu/thcme/mwking/home.html

A good read on Fatty Acid Oxidation:
http://www.indstate.edu/thcme/mwking/fatty-acid-oxidation.html

--
Rudy - Remove the Z from my address to respond.

"It is better to die on your feet than to live on your knees!"
-Emiliano Zapata

Check out the a.s.d.l-c FAQ at:
http://www.grossweb.com/asdlc/faq.htm

RRzVRR said:

Doug Freyburger said:

It's interesting that when you get into the chemistry, ketones
are the only fuel. Both fat and glucose get converted to ketones
before getting burned.

That's incorrect. The body uses both FFA and glucose without
going through ketone production.

A good read on Fatty Acid Oxidation:
http://www.indstate.edu/thcme/mwking/fatty-acid-oxidation.html

That diagram clearly shows fatty acids being converted into a
ketone for consumption in the Krebs cycle.

Fat - fatty acid - ketone in blood - CO2+H2O

Carb - ketone in mitochondria - CO2+H2O

Fat or carb, it gets converted into ketones as it is being burned.

On 19 Aug 2004 15:26:22 -0700, [email hidden] (Doug Freyburger)

Quoted message said:

RRzVRR said:

Doug Freyburger said:

It's interesting that when you get into the chemistry, ketones
are the only fuel. Both fat and glucose get converted to ketones
before getting burned.

That's incorrect. The body uses both FFA and glucose without
going through ketone production.

A good read on Fatty Acid Oxidation:
http://www.indstate.edu/thcme/mwking/fatty-acid-oxidation.html

That diagram clearly shows fatty acids being converted into a
ketone for consumption in the Krebs cycle.

Fat - fatty acid - ketone in blood - CO2+H2O

Carb - ketone in mitochondria - CO2+H2O

Fat or carb, it gets converted into ketones as it is being burned.

Doug,

Rudy is correct. The body uses FFA and glucose without ketone
production. I'll leave it to someone with more time and energy on
their hands to try and explain why your reasoning is confused. Your
"expert" pronouncements are going to need warning labels if you're not
more careful.

"During high rates of fatty acid oxidation, primarily in the liver,
large amounts of acetyl-CoA are generated. These exceed the capacity
of the TCA cycle, and one result is the synthesis of ketone bodies, or
ketogenesis."
Lee Rodgers
Lowcarb Retreat http://www.lowcarb.org
CHAT http://www.lowcarb.org/parachat.html
Low-Carb Connoisseur http://www.low-carb.com

Doug Freyburger said:

RRzVRR said:

Doug Freyburger said:

It's interesting that when you get into the chemistry, ketones
are the only fuel. Both fat and glucose get converted to ketones
before getting burned.

That's incorrect. The body uses both FFA and glucose without
going through ketone production.

A good read on Fatty Acid Oxidation:
http://www.indstate.edu/thcme/mwking/fatty-acid-oxidation.html

No it doesn't. My only guess is that you're thinking that
acetyl CoA is the same as ketones.

Quoted message said:

That diagram clearly shows fatty acids being converted into a
ketone for consumption in the Krebs cycle.

Fat - fatty acid - ketone in blood - CO2+H2O

Carb - ketone in mitochondria - CO2+H2O

Fat or carb, it gets converted into ketones as it is being burned.

You should look into having a better understanding of the Krebs
cycle (also known as the TCA or citric acid cycle). I don't have
the time or desire to explain it here, but there's plenty of good
sites on line that will.

--
Rudy - Remove the Z from my address to respond.

"It is better to die on your feet than to live on your knees!"
-Emiliano Zapata

Check out the a.s.d.l-c FAQ at:
http://www.grossweb.com/asdlc/faq.htm

RRzVRR said:

Doug Freyburger said:

RRzVRR said:

Doug Freyburger wrote:

Quoted message said:

Quoted message said:

> It's interesting that when you get into the chemistry, ketones
> are the only fuel. Both fat and glucose get converted to ketones
> before getting burned.

Quoted message said:

Quoted message said:

That's incorrect. The body uses both FFA and glucose without
going through ketone production.
A good read on Fatty Acid Oxidation:
http://www.indstate.edu/thcme/mwking/fatty-acid-oxidation.html

No it doesn't. My only guess is that you're thinking that
acetyl CoA is the same as ketones.

Acetyl CoA is produced from fatty acids or glucose. Acetyl CoA
is used in the Krebs cycle. In most drawings of the Krebs cycle
Acetyl CoA is fed into the top of the circle, likely because the
folks who figured out how the Krebs cycle worked decided it was
the primary fuel, it having come primarily from carbs. The
decision was a bit circular, but circular works fine when you're
drawing a cycle.

Acetyl CoA is not the only product of fatty acid reduction. Also
produced is oxyactylketone (sp?). This is the ketone that appears
in the blood of folks in ketosis, along with a few others. This
ketone is fed into the Krebs cycle from the right side on most
drawings of the cycle. Getting fed CoA (mostly from glucose but
also from fat) and oxyacetylketone both at the same time acts
rather like a supercharger burning more of both types of fuel.

Part of the metabolic edge of ketosis is those other ketones that
are formed rather than oxyactylketone. For example it's the
acetone that makes the smell. The portion of energy lost to
releasing these other ketones isn't enough to account for the
rapid post-water loss during ketosis, so the supercharger effect
seems to dominate.

What in the above did I get wrong? Is Acetyl CoA an acetate
rather than a ketone? That would explain why acetates are
called the primary fuel, but the similarity between acetate
and ketone on the level got me.

Assuming that's my mistake, I'll try my original statement
over:

Acetate plus ketone is the only fuel anyways. There are
metabolic pathways from glucose to both acetate and ketones
during aerobic respiration. There are metabolic pathways
from fatty acid to both acetate and ketones during aerobic
respiration. Better? Still wrong? Thanks for the training.

(Doug Freyburger) said:

This ketone is fed into the Krebs cycle from the right side on most
drawings of the cycle.

Either I'm misreading all the drawings, or the first six I found
weren't "most" drawings. Could you post an URL of a Krebs cycle
drawing that shows this?

DJ Delorie wrot:

Quoted message said:

Doug Freyburger said:

This ketone is fed into the Krebs cycle from the right side on most
drawings of the cycle.

Either I'm misreading all the drawings, or the first six I found
weren't "most" drawings. Could you post an URL of a Krebs cycle
drawing that shows this?

This one shows both Acetyl CoA and oxaloacetate (named acetate but
it is the common ketone in ketosis) coming in at the top:

http://www.people.virginia.edu/~rjh9u/krebs.html

Another top:

http://chemistry.gsu.edu/glactone/PDB/Proteins/Krebs/Krebs.html

This one shows it one step to the left rather than right:

http://www.accessexcellence.org/RC/VL/GG/citric_Cyc.html

Another right:

http://www.gwu.edu/~mpb/citric.htm

Here's the one with the right hand entry that I learned back
in high school biochem, and its a wonderful animation:

http://www.wiley.com/legacy/college/boyer/0470003790/animations/tca/tca.htm

Interesting. Diagrams that show just the cycle show it added on
the left and diagrams that show how it comes from fat show it
added in on the left.

(Doug Freyburger) said:

This one shows both Acetyl CoA and oxaloacetate (named acetate but
it is the common ketone in ketosis) coming in at the top:

They all show oxaloacetate as one of the parts of the cycle, not as
input fuel. IOW, it's produced and consumed in equal parts, striking
a balance. Acetyl CoA on the other hand, is consumed but not
replaced, so that's fuel. At best, OA is a catalyst.

Doug Freyburger said:

RRzVRR said:

Doug Freyburger said:

RRzVRR wrote:

>Doug Freyburger wrote:

Quoted message said:

>>It's interesting that when you get into the chemistry, ketones
>>are the only fuel. Both fat and glucose get converted to ketones
>>before getting burned.

Quoted message said:

>That's incorrect. The body uses both FFA and glucose without
>going through ketone production.
>A good read on Fatty Acid Oxidation:
>http://www.indstate.edu/thcme/mwking/fatty-acid-oxidation.html

No it doesn't. My only guess is that you're thinking that
acetyl CoA is the same as ketones.

Quoted message said:

Acetyl CoA is produced from fatty acids or glucose. Acetyl CoA
is used in the Krebs cycle.

Which takes us back to the original point of this discussion.

FFA and glucose are used as fuel without having to be turned into
ketones.

FFA use as a fuel provides the acetyl-CoA that in turn is used to
create ketone bodies: acetoacetate, b-hydroxybutyrate, and
acetone. Ketones are the byproduct of FFA use and is just one of
the a handy recycle programs the body uses.

Quoted message said:

In most drawings of the Krebs cycle
Acetyl CoA is fed into the top of the circle, likely because the
folks who figured out how the Krebs cycle worked decided it was
the primary fuel, it having come primarily from carbs. The
decision was a bit circular, but circular works fine when you're
drawing a cycle.

FFA also provides acetyl-CoA.

Quoted message said:

Acetyl CoA is not the only product of fatty acid reduction. Also
produced is oxyactylketone (sp?). This is the ketone that appears
in the blood of folks in ketosis, along with a few others. This
ketone is fed into the Krebs cycle from the right side on most
drawings of the cycle. Getting fed CoA (mostly from glucose but
also from fat) and oxyacetylketone both at the same time acts
rather like a supercharger burning more of both types of fuel.

Maybe your thinking b-hydroxybutyrate?

Quoted message said:

What in the above did I get wrong? Is Acetyl CoA an acetate
rather than a ketone? That would explain why acetates are
called the primary fuel, but the similarity between acetate
and ketone on the level got me.

Assuming that's my mistake, I'll try my original statement
over:

Acetate plus ketone is the only fuel anyways. There are
metabolic pathways from glucose to both acetate and ketones
during aerobic respiration. There are metabolic pathways
from fatty acid to both acetate and ketones during aerobic
respiration. Better? Still wrong? Thanks for the training.

In short, there are multiple pathways and systems that provide
fuel, ketone production just only one component of one system.
The depth of all the systems is beyond what can be explained to
you in a post. I'm don't have the technical writing skills or
the time to offer what's already provided by many good .edu sites
found on the web... plus the graphic representations help a lot.

The best advice I'll offer is that you might want to start at the
end -- look at ATP (adenosine triphosphate) and systems that
provide ATP. Go down each of those paths and see where the
components come from.

Being self taught, I know that it takes repitition to "get" even
part of the many fuel systems, their feedback and recycle
processes. But if you'll look at it from a fresh mind and
thinking efficiency it will start to make some sense.

--
Rudy - Remove the Z from my address to respond.

"It is better to die on your feet than to live on your knees!"
-Emiliano Zapata

Check out the a.s.d.l-c FAQ at:
http://www.grossweb.com/asdlc/faq.htm

Doug Freyburger said:

DJ Delorie wrot:

Quoted message said:

Doug Freyburger said:

This ketone is fed into the Krebs cycle from the right side on most
drawings of the cycle.

Either I'm misreading all the drawings, or the first six I found
weren't "most" drawings. Could you post an URL of a Krebs cycle
drawing that shows this?

This one shows both Acetyl CoA and oxaloacetate (named acetate but
it is the common ketone in ketosis) coming in at the top:

Acetate is not shorthand for oxaloacetate, they are two different
elements. And, are you confusing acetate with the keotne bodies
acetoacetate or acetone?

You're looking at all of this from a biased point of view.
You're looking to make the puzzle pieces fit your objective and
that's keeping you from seeing a clear picture.

--
Rudy - Remove the Z from my address to respond.

"It is better to die on your feet than to live on your knees!"
-Emiliano Zapata

Check out the a.s.d.l-c FAQ at:
http://www.grossweb.com/asdlc/faq.htm

Doug Freyburger said:

Quoted message said:

No it doesn't. My only guess is that you're thinking that
acetyl CoA is the same as ketones.

Acetyl CoA is produced from fatty acids or glucose. Acetyl CoA
is used in the Krebs cycle. In most drawings of the Krebs cycle
Acetyl CoA is fed into the top of the circle, likely because the
folks who figured out how the Krebs cycle worked decided it was
the primary fuel, it having come primarily from carbs. The
decision was a bit circular, but circular works fine when you're
drawing a cycle.

Just to try and make this clear. FFA is broken down to create
acetyl-CoA. Glucose is broken down to create acetyl-CoA. Ketones
are broken down to create acetyl-CoA. Its acetyl-CoA that inters
the cycle so it doesn't matter to the cycle whether acetyl-CoA
comes from.

Quoted message said:

Acetyl CoA is not the only product of fatty acid reduction. Also
produced is oxyactylketone (sp?).

Are you thinking of oxaloacetate?

Quoted message said:

This is the ketone that appears
in the blood of folks in ketosis, along with a few others.

The ketones that are produced FROM acetyl CoA are: acetoacetate,
beta-hydroxybutyrate, and acetone. In ketosis oxaloacetate is
used in gluconeogenesis.

Quoted message said:

This
ketone is fed into the Krebs cycle from the right side on most
drawings of the cycle. Getting fed CoA (mostly from glucose but
also from fat) and oxyacetylketone both at the same time acts
rather like a supercharger burning more of both types of fuel.

Acetoacetate and b-hydroxybutyrate are used by muscle (including
heart), kidney & brain for energy if available, its acetone that
isn't used, but release.

Quoted message said:

Part of the metabolic edge of ketosis is those other ketones that
are formed rather than oxyactylketone. For example it's the
acetone that makes the smell. The portion of energy lost to
releasing these other ketones isn't enough to account for the
rapid post-water loss during ketosis, so the supercharger effect
seems to dominate.

What in the above did I get wrong? Is Acetyl CoA an acetate
rather than a ketone?

Acetyl-CoA is a building block for ketone production -- as well
as FFA to be stored.
Acetate from pyruvate (which comes from glucose) -- it can create
acetyl-CoA.

Quoted message said:

That would explain why acetates are
called the primary fuel, but the similarity between acetate
and ketone on the level got me.

Assuming that's my mistake, I'll try my original statement
over:

Acetate plus ketone is the only fuel anyways. There are
metabolic pathways from glucose to both acetate and ketones
during aerobic respiration. There are metabolic pathways
from fatty acid to both acetate and ketones during aerobic
respiration. Better? Still wrong? Thanks for the training.

You're missing a lot of details and skipping an complete system.

Lets go back to the issue that started this discussion. Cell
energy can come from FFA or glucose (because they end up creating
acetyl-CoA) without any need for ketones for energy. If there's
an abunance to acetyl-CoA (from FFA use) along with low levels of
insulin, that will then lead to ketone production. Ketones are
created and are recycled back into acetyl-CoA.

The body's fuel systems have multiple paths and recycle systems.
Ketone production and use is just one part, of one system.

I've gotten the impression that your point of view has clouded
your ability clearly take in these complex systems easily because
you want them to all go in a set direction. And that all the
reading and discussion in this area will only confuse things more
for you and delay your understanding. Put this all down and come
back to it when you're not looking for the answer you want to
find. All the information on this is on the web and you can get
back to it when your ready. Frankly I don't have the time to go
into this when I know there are there are better resources for
you to learn with when your viewpoint is clear.

In short, We could point to the forrest all day, but if you're
only looking for oak trees, you'll never see it.

--
Rudy - Remove the Z from my address to respond.

"It is better to die on your feet than to live on your knees!"
-Emiliano Zapata

Check out the a.s.d.l-c FAQ at:
http://www.grossweb.com/asdlc/faq.htm

Hi Rudy (and Doug),
I've been watching this thread, staying out of it because frankly Doug
doesn't respond to attempts by me to teach him things. That
aggravates me so I passed. In my meanderings I did find a site that
may help people get a handle on metabolic processes though, so here it
is:

http://library.thinkquest.org/~11226/

Yes, I know that they use a cartoon Captain Carbon, but the text isn't
hideously dumbed down.

Enjoy!

Take care,
Carmen

On Sun, 22 Aug 2004 13:47:59 GMT, "Carmen" <[email hidden]>

Quoted message said:

Hi Rudy (and Doug),
I've been watching this thread, staying out of it because frankly Doug
doesn't respond to attempts by me to teach him things. That
aggravates me so I passed. In my meanderings I did find a site that
may help people get a handle on metabolic processes though, so here it
is:

http://library.thinkquest.org/~11226/

Yes, I know that they use a cartoon Captain Carbon, but the text isn't
hideously dumbed down.

Enjoy!

Take care,
Carmen

Hey that's a great page Carmen. Thanks for the heads up. I made
"Captain Carbon's Biochemistry Primer" #48 in the bright yellow
Health Info section on The Lowcarb Retreat. The Captain covers
protein and carbohydrate. I wonder if he has plans to add fat to his
page? The Captain makes it easier to understand than Goldberg. Yay
team! Can we make Captain Carbon required reading? You are such a
good sourcer. There should be some kind of medal for that. OK enough
gushing before I trigger a hyperglycemic episode. 🙂
Lee Rodgers
Lowcarb Retreat http://www.lowcarb.org
CHAT http://www.lowcarb.org/parachat.html
Low-Carb Connoisseur http://www.low-carb.com

Hi,

(Lee Rodgers) said:

On Sun, 22 Aug 2004 13:47:59 GMT, "Carmen" <[email hidden]>

Quoted message said:

Hi Rudy (and Doug),
I've been watching this thread, staying out of it because frankly
Doug
doesn't respond to attempts by me to teach him things. That
aggravates me so I passed. In my meanderings I did find a site that
may help people get a handle on metabolic processes though, so here
it is:

http://library.thinkquest.org/~11226/

Yes, I know that they use a cartoon Captain Carbon, but the text
isn't hideously dumbed down.

Enjoy!

Take care,
Carmen

Hey that's a great page Carmen. Thanks for the heads up. I made
"Captain Carbon's Biochemistry Primer" #48 in the bright yellow
Health Info section on The Lowcarb Retreat. The Captain covers
protein and carbohydrate. I wonder if he has plans to add fat to
his page? The Captain makes it easier to understand than Goldberg.
Yay
team! Can we make Captain Carbon required reading? You are such a
good sourcer. There should be some kind of medal for that. OK
enough gushing before I trigger a hyperglycemic episode. 🙂

Thanks Lee. :-)
What did you think about the fate of poor Sam? <G>

Take care,
Carmen

Carmen said:

http://library.thinkquest.org/~11226/

Yes, I know that they use a cartoon Captain Carbon, but the text isn't
hideously dumbed down.

Thanks, that is a good site... mainly because it starts at the
very beginning and then progresses. Most of the other sites
assume you know what and where the compounds come from.

As I said before I'm self taught, never having taken a chemisty
couse, so its been by want and repetion that I've learn what I
have so far. So anytime you come across a good
biochemistry/physiology/metablolism sites let me know.

--
Rudy - Remove the Z from my address to respond.

"It is better to die on your feet than to live on your knees!"
-Emiliano Zapata

Check out the a.s.d.l-c FAQ at:
http://www.grossweb.com/asdlc/faq.htm

Carmen said:

I've been watching this thread, staying out of it because frankly Doug
doesn't respond to attempts by me to teach him things.

Freyburger? No, not Doug Freyburger. Surely you jest.

Quoted message said:

That
aggravates me so I passed

I know the feeling. Except for the aggravation part. Got over that years
ago.

Hi,

RRzVRR said:

Carmen said:

http://library.thinkquest.org/~11226/

Yes, I know that they use a cartoon Captain Carbon, but the text
isn't hideously dumbed down.

Thanks, that is a good site... mainly because it starts at the
very beginning and then progresses. Most of the other sites
assume you know what and where the compounds come from.

That was the best thing about it. The author(s) are good teachers.
Not my forte, but I can recognize it in others.

Quoted message said:

As I said before I'm self taught, never having taken a chemisty
couse, so its been by want and repetion that I've learn what I
have so far. So anytime you come across a good
biochemistry/physiology/metablolism sites let me know.

Will do. :-)

Take care,
carmen