Beta Oxidation Vs Glycolysis

[Peatit]

I am a little confused because from what I read (and understand) I can't conclude that glycolysis is superior to Beta oxidation (at least of SFAs) as a prerequisite for the Krebs cycle and electron transport chain.
Could someone enlighten me?

 

[Peatit]

Well now I can even go a step further saying that beta oxidation seems to me superior to glycolysis regarding energy yield (comparing carbon to carbon result).
For example complete oxidation (beta oxidation followed by citric cycle and oxidative phosphorylation) of one molecule of palmitic acid (18C) gives 106 ATP VS complete oxidation (glycolysis followed by citric cycle and oxidative phosphorylation) of one molecule of glucose (6C) gives 32 ATP
Source (for those who can read French)

 

[paymanz]

from what i know , carb oxidation is superior in co2 production.and also the situations that cause you to burn fat are stressful situations.for example if you have your glycogen stores depleted.and when that happens also insulin resistant come afterward,with high FFA in blood.

 

[Parsifal]

Well now I can even go a step further saying that beta oxidation seems to me superior to glycolysis regarding energy yield (comparing carbon to carbon result).
For example complete oxidation (beta oxidation followed by citric cycle and oxidative phosphorylation) of one molecule of palmitic acid (6C) gives 44 ATP VS complete oxidation (glycolysis followed by citric cycle and oxidative phosphorylation) of one molecule of glucose (6C) gives 32 ATP
Source (for those who can read French)

Is beta-oxydation ketosis? I'm not sure but maybe it doesn't produce much carbon dioxyde? Also it seems sugar and things like fructose have benefits that fat or other sugars don't have (reproduction, etc)?

 

[paymanz]

if you dont let glycogen stores deplete and then get remaining energy requirement from sat fats, coconut oil , mct oil , butter.then that is good i think especially for sedentary lifestyles. ray have said in an email its ok to have up to 50% of energy from safe fats.but anyway you get a little more pufa per energy unit from fat foods.

 

[paymanz]

some sources claim MCT and coconut oil can increase ketones in body even without fasting on carbs! but im not sure how correct that can be?!

 

[Peatit]

Ketosis seems to happen when beta oxidation production of acetyl-CoA exceeds Krebs cycle processing abilities (mainly if hepatic neogluconeogenesis is using oxaloacetic acid).
You're both right,the production of CO2 is seemingly affected because even glycolysis and beta oxidation don't produce any CO2 on their own (most of it is produced later in the subsequent common metabolic pathways Krebs cycle and oxidative phosphorylation), beta oxidation don't generate pyruvate (it leads directly to acetyl-CoA) and so you don't get CO2 from pyruvate decarboxylation. Now that reminds me an episode of politics & science where RP said exactly that the main problem of fat oxidation is that less CO2 is produced.
Yes I heard Haidut in a generative energy making very good points saying that the body uses fructose for semen and in the amniotic fluid I think, entrusting the survival of its most important function (reproduction) to this sugar.

 

[Peatit]

So one question still stands: is it preferable to get more CO2 or more ATP?

 

[paymanz]

yes especially fructose affect this ATP.

andrew kim blog has some articles on it.im not fluent on technical things.but after i saw your post searched and found this one Nutrition|Digital Textbook Library

the table,havent seen such info before.

 

[Peatit]

This table seems wrong, might be a typo, all others I can come across show a RQ inferior for fat compared to glucose, this one for example: Respiratory quotient – Energy sources

 

[paymanz]

This table seems wrong, might be a typo, all others I can come across show a RQ inferior for fat compared to glucose, this one for example: Respiratory quotient – Energy sources

no it listed RQ higher for carb...take a look again,but other data are new to me, like the amount of O2 it use and amount of co2.

 

[Peatit]

no it listed RQ higher for carb...take a look again,but other data are new to me, like the amount of O2 it use and amount of co2.

Isn't it what I wrote before? RQ for carb is 1; RQ for fat is 0.67, so RQ for carb is the highest indeed.

 

[paymanz]

@Peatit yeah i just shared that link because it was a bit interesting for me.

it says 1 gram of fat uses O2 as twice as carb.but per unit of energy it still carb higher RQ.
1 gram of fat 37 kJ
1 gram of carbohydrates 17 kJ
so there is no actual point in that link

 

[Peatit]

@Peatit yeah i just shared that link because it was a bit interesting for me.

it says 1 gram of fat uses O2 as twice as carb.but per unit of energy it still carb higher RQ.
1 gram of fat 37 kJ
1 gram of carbohydrates 17 kJ
so there is no actual point in that link

yeah sorry I misread your table

 

[Pointless]

Ray Peat has said that there's nothing wrong with ketones. The problem is the fatty acids. If you could get a source of pure ketones, it would have a protective effect, according to RP. Search this page for "ketone" for answers to some of your questions. Medium Chain Fats, Ketones, and Brain Function – Functional Performance Systems (FPS)

 

[Peatit]

Ray Peat has said that there's nothing wrong with ketones. The problem is the fatty acids. If you could get a source of pure ketones, it would have a protective effect, according to RP. Search this page for "ketone" for answers to some of your questions. Medium Chain Fats, Ketones, and Brain Function – Functional Performance Systems (FPS)

Well FA beta oxidation doesn't seem problematic, I would rather say suboptimal because of the decrease CO2 output (RQ like paymanz pointed out) and even then, I don't know if the little extra ATP produced doesn't "compensate". Of course this is pure speculation and I would be glad if somebody could bring light on the topic.
On the FPS page you kindly shared there's even a quote attributed to RP saying that: "Short and medium chain fatty acids are used more easily than glucose, and it is apparently this fact which accounts for their presence in milk."

 

[paymanz]

i think peatit question is not at practical level, he wants understand the logic.

 

[Peatit]

i think peatit question is not at practical level, he wants understand the logic.

Absolutely, thank you @paymanz, I should have been more specific.

 

[thegiantess]

Well FA beta oxidation doesn't seem problematic, I would rather say suboptimal because of the decrease CO2 output (RQ like paymanz pointed out) and even then, I don't know if the little extra ATP produced doesn't "compensate". Of course this is pure speculation and I would be glad if somebody could bring light on the topic.
On the FPS page you kindly shared there's even a quote attributed to RP saying that: "Short and medium chain fatty acids are used more easily than glucose, and it is apparently this fact which accounts for their presence in milk."

Now I'm interested in your question of which is more valuable, ATP or CO2. I think Haidut is likely the most knowledgable on this subject. Perhaps tag him in a post and he will chime in.

Also, that quote above where RP says that mcts are used more easily than glucose just confuses me. So then why does he not recommended a diet higher in coconut oil?

 

[Wilfrid]

Is that possible that the more ATP that occur with the beta oxidation pathway result from a shift in energy resources (beta-oxidation is dependant from lipases that are activated by epinephrine, norepinephrine, glucagon and cortisol, often described as catabolic hormones ) to provide more energy for brain and muscles in a situation that the organism may falsy interpret like a stressful one? much like the one that can be seen in the fight or flight response?
Hence, like in a sustained response to stressful and traumatic events ( endogenous and/or exogenous), the major goal here is to provide more energy and then more ATP. But a transient decline in immunity could be one cost of this energetic shift.
If that the case, only people with good liver, kidneys and hormonal/mental status could sustain on this metabolic pathway, what do you think?