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How does the body fuel itself?

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Replies

  • tennisdude2004
    tennisdude2004 Posts: 5,609 Member
    psuLemon wrote: »
    CSARdiver wrote: »
    Here's my analogy:

    You have a car that's engineered and built to run on premium gasoline.

    There's a gas shortage, and the only thing available at the pumps is the cheap crap, so you switch to that instead.

    Will your car run?

    Of course it will.

    Will it run at peak efficiency and performance?

    Not a chance.

    Do you have scientific evidence that the brain operates less optimally on a fuel mixture of glucose, ketones and lactate, or are you just stating opinion?

    Not scientific evidence, but I note that the arguments posed by the keto-evangelists are distinctly lacking in rationale and objective evidence.

    Commonplace where one allows agenda to drive the process.

    The argument that the brain is NOT Exclusively fuelled by glucose has been supported by evidence.

    no evidence has been given put forward that the brain is exclusively fuelled by glucose has been put forward or that the brain operates in a less than optimal capacity if it is not exclusively fuelled by glucose.

    The statement that started this particular discussion about glucose being the only fuel the brain can use is false and misleading.

    I believe it was thr preffered source of fuel from the brain was glucose over ketones, since ketones only are used as fuel when deprived of glucose.

    Yep that’s my understanding of how the brain is fuelled also, that if glucose is readily available it is the preferred option.

    I am also of the understanding that when glucose is restricted that the brain will function just as optimally on a mixture of ketones, glucose and lactate.

    Also that even when glucose is in ample supply the brain will also draw upon lactate for fuel when the body is undertaking vigorous exercise.

    All of the above is very different factually from the brain only being able to use glucose for fuel - wouldn’t you agree?

    It is. Which is why nobody made that assertion in the first place.

    “The brain is fueled exclusively by glucose.”

    Page one. Maybe you just hadn’t scrolled back that far?

    Selective quote is selective
    "Glucose is virtually the sole fuel for the human brain, except during prolonged starvation. The brain lacks fuel stores and hence requires a continuous supply of glucose. It consumes about 120 g daily, which corresponds to an energy input of about 420 kcal (1760 kJ), accounting for some 60% of the utilization of glucose by the whole body in the resting state...

    ...Fatty acids do not serve as fuel for the brain, because they are bound to albumin in plasma and so do not traverse the blood-brain barrier. In starvation, ketone bodies generated by the liver partly replace glucose as fuel for the brain."[/i]

    You must have missed the part about alternate fuel sources in the absence of glucose.

    Also i don’t think you mean ‘absence’ of glucose! You must mean limited availability.
  • psuLemon
    psuLemon Posts: 38,427 MFP Moderator
    CSARdiver wrote: »
    psuLemon wrote: »
    psuLemon wrote: »
    CSARdiver wrote: »
    Here's my analogy:

    You have a car that's engineered and built to run on premium gasoline.

    There's a gas shortage, and the only thing available at the pumps is the cheap crap, so you switch to that instead.

    Will your car run?

    Of course it will.

    Will it run at peak efficiency and performance?

    Not a chance.

    Do you have scientific evidence that the brain operates less optimally on a fuel mixture of glucose, ketones and lactate, or are you just stating opinion?

    Not scientific evidence, but I note that the arguments posed by the keto-evangelists are distinctly lacking in rationale and objective evidence.

    Commonplace where one allows agenda to drive the process.

    The argument that the brain is NOT Exclusively fuelled by glucose has been supported by evidence.

    no evidence has been given put forward that the brain is exclusively fuelled by glucose has been put forward or that the brain operates in a less than optimal capacity if it is not exclusively fuelled by glucose.

    The statement that started this particular discussion about glucose being the only fuel the brain can use is false and misleading.

    I believe it was thr preffered source of fuel from the brain was glucose over ketones, since ketones only are used as fuel when deprived of glucose.

    Yep that’s my understanding of how the brain is fuelled also, that if glucose is readily available it is the preferred option.

    I am also of the understanding that when glucose is restricted that the brain will function just as optimally on a mixture of ketones, glucose and lactate.

    Also that even when glucose is in ample supply the brain will also draw upon lactate for fuel when the body is undertaking vigorous exercise.

    All of the above is very different factually from the brain only being able to use glucose for fuel - wouldn’t you agree?

    It is. Which is why nobody made that assertion in the first place.

    “The brain is fueled exclusively by glucose.”

    Page one. Maybe you just hadn’t scrolled back that far?

    Selective quote is selective
    "Glucose is virtually the sole fuel for the human brain, except during prolonged starvation. The brain lacks fuel stores and hence requires a continuous supply of glucose. It consumes about 120 g daily, which corresponds to an energy input of about 420 kcal (1760 kJ), accounting for some 60% of the utilization of glucose by the whole body in the resting state...

    ...Fatty acids do not serve as fuel for the brain, because they are bound to albumin in plasma and so do not traverse the blood-brain barrier. In starvation, ketone bodies generated by the liver partly replace glucose as fuel for the brain."[/i]

    You must have missed the part about alternate fuel sources in the absence of glucose.

    Great so we are all in agreement then that statement that the brain exclusively uses glucose for fuel is false?

    Because so far there’s been lots of deflecting from answering this question. :wink:

    It's just as false as there being many low carb and keto athletes that thrive, while considering the population of athletes. That being, that might be one or two in a population of thousands of professional athletes. :p

    I still have a few friends over at NAVSPECWARCEN and will ask the physicians if they ever considered the keto diet within any of the special operations schools.

    Sure this will be taken very seriously...

    Interestingly enough, that is some of the specialized work done by Dom D'Aginstino.
  • mmapags
    mmapags Posts: 8,934 Member
    CSARdiver wrote: »
    nvmomketo wrote: »
    Do you think that was humans main energy source was back in the day when you all didn't have such easy access to the garbage carbs you are feeding yourselves with now days. Do you think when humans ate mostly fat and protein their bodies metabolisms ran the same as your high carb metabolism does??

    This is an odd point to make. When we observe our closest animal relatives, what do they eat? Plants mostly (including lots of fruit), supplemented with some meat (animal and insect) and nuts/seeds. Early humans probably did the same, wouldn't you think? At what point were humans eating mostly fat and protein and avoiding carbohydrates?

    Our teeth and digestive systems seem to more closely resemble that of dogs rather than that of chimps - meat eaters that can supplement with plant products (Omnivores).

    I think your argument depends on where your ancestors came from. Mine are northern European (Russian, Norwegian, British, Sottish, German). They ate mostly animals with some plants. I think it was the Romans who brought in agriculture around 3000 years ago.

    Now I live where the First Nations Plains peoples lived. Meat from grazers was the natural main food source in this part of the world for thousands of years. To get plants, beyond some dried berries or herbs, for 6+ months of the year was very hard until the railroad was put in.

    Some cultures were more animal based than others. It's not because they were avoiding carbohydrates. It's because edible carbohydrates were not readily available. Tubers and fruits on bushes is not always easily available.

    Humans were eating plants before agriculture was developed. That's my point: look at primate diets, they're always eating plants. The proportion of plants to meat would vary by area/time of year/general availability, but plants are always present there. Some humans expanded out to areas where they ate much more meat than plants -- this is possible precisely because we're omnivores. Some humans expanded to areas where they ate more plants -- again, us being omnivores is what makes this possible.

    I'm not arguing that humans can't thrive on a diet that is mostly meat. Evidence shows that humans can thrive on this diet, along with other types of diet. I'm responding specifically to someone who is claiming that a high carbohydrate diet is somehow new to humans and that such a diet is "garbage." A high carbohydrate diet isn't new to humans. It wouldn't even be new to pre-human ancestors (if the diets of our primate relatives are any indication).

    Edit: I'm not claiming any groups historically avoided carbohydrates. I think the opposite. I think any human group who found easy access to carbohydrates probably would eat them -- humans often find them tasty and they're a good source of energy. Why would they avoid them? The people who had consistent access to things like berries, tubers, wild grains, and greens were *lucky*.

    Don't forget the bugs. Prior to agriculture we were opportunity hunters which meant that our diets were largely subsidized on insects.

    ....so....for you true paleo types I hope you have a worm farm running at capacity.

    Lol, here in Oaxaca where I am living, they still eat bugs. Chapulines (grasshoppers) are a staple and all the natives are very excited that this week is the week for chicatanas, a large edible ant that is supposedly delicious. They only hatch over a few day period and there were a few out on the ground today. There are also a couple types of worms they eat.
  • CSARdiver
    CSARdiver Posts: 6,252 Member
    psuLemon wrote: »
    CSARdiver wrote: »
    psuLemon wrote: »
    psuLemon wrote: »
    CSARdiver wrote: »
    Here's my analogy:

    You have a car that's engineered and built to run on premium gasoline.

    There's a gas shortage, and the only thing available at the pumps is the cheap crap, so you switch to that instead.

    Will your car run?

    Of course it will.

    Will it run at peak efficiency and performance?

    Not a chance.

    Do you have scientific evidence that the brain operates less optimally on a fuel mixture of glucose, ketones and lactate, or are you just stating opinion?

    Not scientific evidence, but I note that the arguments posed by the keto-evangelists are distinctly lacking in rationale and objective evidence.

    Commonplace where one allows agenda to drive the process.

    The argument that the brain is NOT Exclusively fuelled by glucose has been supported by evidence.

    no evidence has been given put forward that the brain is exclusively fuelled by glucose has been put forward or that the brain operates in a less than optimal capacity if it is not exclusively fuelled by glucose.

    The statement that started this particular discussion about glucose being the only fuel the brain can use is false and misleading.

    I believe it was thr preffered source of fuel from the brain was glucose over ketones, since ketones only are used as fuel when deprived of glucose.

    Yep that’s my understanding of how the brain is fuelled also, that if glucose is readily available it is the preferred option.

    I am also of the understanding that when glucose is restricted that the brain will function just as optimally on a mixture of ketones, glucose and lactate.

    Also that even when glucose is in ample supply the brain will also draw upon lactate for fuel when the body is undertaking vigorous exercise.

    All of the above is very different factually from the brain only being able to use glucose for fuel - wouldn’t you agree?

    It is. Which is why nobody made that assertion in the first place.

    “The brain is fueled exclusively by glucose.”

    Page one. Maybe you just hadn’t scrolled back that far?

    Selective quote is selective
    "Glucose is virtually the sole fuel for the human brain, except during prolonged starvation. The brain lacks fuel stores and hence requires a continuous supply of glucose. It consumes about 120 g daily, which corresponds to an energy input of about 420 kcal (1760 kJ), accounting for some 60% of the utilization of glucose by the whole body in the resting state...

    ...Fatty acids do not serve as fuel for the brain, because they are bound to albumin in plasma and so do not traverse the blood-brain barrier. In starvation, ketone bodies generated by the liver partly replace glucose as fuel for the brain."[/i]

    You must have missed the part about alternate fuel sources in the absence of glucose.

    Great so we are all in agreement then that statement that the brain exclusively uses glucose for fuel is false?

    Because so far there’s been lots of deflecting from answering this question. :wink:

    It's just as false as there being many low carb and keto athletes that thrive, while considering the population of athletes. That being, that might be one or two in a population of thousands of professional athletes. :p

    I still have a few friends over at NAVSPECWARCEN and will ask the physicians if they ever considered the keto diet within any of the special operations schools.

    Sure this will be taken very seriously...

    Interestingly enough, that is some of the specialized work done by Dom D'Aginstino.

    Interesting indeed. I'm quite serious about this - the special operations community is successful because of the quality of continually questioning everything and are always looking for the latest innovations. Why you find that the majority of modifications to sports medicine often originated within one of the teams.

    The only counter is that you would never want to limit or restrict a viable food source. Adaptability is paramount.
  • CSARdiver
    CSARdiver Posts: 6,252 Member
    mmapags wrote: »
    CSARdiver wrote: »
    nvmomketo wrote: »
    Do you think that was humans main energy source was back in the day when you all didn't have such easy access to the garbage carbs you are feeding yourselves with now days. Do you think when humans ate mostly fat and protein their bodies metabolisms ran the same as your high carb metabolism does??

    This is an odd point to make. When we observe our closest animal relatives, what do they eat? Plants mostly (including lots of fruit), supplemented with some meat (animal and insect) and nuts/seeds. Early humans probably did the same, wouldn't you think? At what point were humans eating mostly fat and protein and avoiding carbohydrates?

    Our teeth and digestive systems seem to more closely resemble that of dogs rather than that of chimps - meat eaters that can supplement with plant products (Omnivores).

    I think your argument depends on where your ancestors came from. Mine are northern European (Russian, Norwegian, British, Sottish, German). They ate mostly animals with some plants. I think it was the Romans who brought in agriculture around 3000 years ago.

    Now I live where the First Nations Plains peoples lived. Meat from grazers was the natural main food source in this part of the world for thousands of years. To get plants, beyond some dried berries or herbs, for 6+ months of the year was very hard until the railroad was put in.

    Some cultures were more animal based than others. It's not because they were avoiding carbohydrates. It's because edible carbohydrates were not readily available. Tubers and fruits on bushes is not always easily available.

    Humans were eating plants before agriculture was developed. That's my point: look at primate diets, they're always eating plants. The proportion of plants to meat would vary by area/time of year/general availability, but plants are always present there. Some humans expanded out to areas where they ate much more meat than plants -- this is possible precisely because we're omnivores. Some humans expanded to areas where they ate more plants -- again, us being omnivores is what makes this possible.

    I'm not arguing that humans can't thrive on a diet that is mostly meat. Evidence shows that humans can thrive on this diet, along with other types of diet. I'm responding specifically to someone who is claiming that a high carbohydrate diet is somehow new to humans and that such a diet is "garbage." A high carbohydrate diet isn't new to humans. It wouldn't even be new to pre-human ancestors (if the diets of our primate relatives are any indication).

    Edit: I'm not claiming any groups historically avoided carbohydrates. I think the opposite. I think any human group who found easy access to carbohydrates probably would eat them -- humans often find them tasty and they're a good source of energy. Why would they avoid them? The people who had consistent access to things like berries, tubers, wild grains, and greens were *lucky*.

    Don't forget the bugs. Prior to agriculture we were opportunity hunters which meant that our diets were largely subsidized on insects.

    ....so....for you true paleo types I hope you have a worm farm running at capacity.

    Lol, here in Oaxaca where I am living, they still eat bugs. Chapulines (grasshoppers) are a staple and all the natives are very excited that this week is the week for chicatanas, a large edible ant that is supposedly delicious. They only hatch over a few day period and there were a few out on the ground today. There are also a couple types of worms they eat.

    Sugar ants! Very tasty indeed - even better fermented. You can keep the worms...they all taste like dirt no matter how you prep them.
  • kpk54
    kpk54 Posts: 4,474 Member
    CSARdiver wrote: »
    I still have a few friends over at NAVSPECWARCEN and will ask the physicians if they ever considered the keto diet within any of the special operations schools.

    Sure this will be taken very seriously...

    A bit off topic and not offering a pro or con here regarding keto but it really might be an interesting discussion.

    A bit of what interested me as an aside when 1st started researching keto was the ketogenic research/application being conducted by Dr. (PhD) Domenic D'Agostino and the US Navy regarding oxygen toxicity and US Navy Divers. Trying to find a way to eliminate seizures in the divers while in the depths of the ocean. I had an uncle (now deceased) who was last stationed at the Naval Diving Training Center in Panama City and was a Master Diver with the US Navy serving in Vietnam (which was the "connection" of interest). D'Agostino has several interviews on line mentioning this research as "how he became interested in the ketogenic diet".

    Carry on...
  • psuLemon
    psuLemon Posts: 38,427 MFP Moderator
    kpk54 wrote: »
    CSARdiver wrote: »
    I still have a few friends over at NAVSPECWARCEN and will ask the physicians if they ever considered the keto diet within any of the special operations schools.

    Sure this will be taken very seriously...

    A bit off topic and not offering a pro or con here regarding keto but it really might be an interesting discussion.

    A bit of what interested me as an aside when 1st started researching keto was the ketogenic research/application being conducted by Dr. (PhD) Domenic D'Agostino and the US Navy regarding oxygen toxicity and US Navy Divers. Trying to find a way to eliminate seizures in the divers while in the depths of the ocean. I had an uncle (now deceased) who was last stationed at the Naval Diving Training Center in Panama City and was a Master Diver with the US Navy serving in Vietnam (which was the "connection" of interest). D'Agostino has several interviews on line mentioning this research as "how he became interested in the ketogenic diet".

    Carry on...

    His interview with Layne Norton PhD, is what turned me onto his work. Its really interested.
  • kpk54
    kpk54 Posts: 4,474 Member
    psuLemon wrote: »
    kpk54 wrote: »
    CSARdiver wrote: »
    I still have a few friends over at NAVSPECWARCEN and will ask the physicians if they ever considered the keto diet within any of the special operations schools.

    Sure this will be taken very seriously...

    A bit off topic and not offering a pro or con here regarding keto but it really might be an interesting discussion.

    A bit of what interested me as an aside when 1st started researching keto was the ketogenic research/application being conducted by Dr. (PhD) Domenic D'Agostino and the US Navy regarding oxygen toxicity and US Navy Divers. Trying to find a way to eliminate seizures in the divers while in the depths of the ocean. I had an uncle (now deceased) who was last stationed at the Naval Diving Training Center in Panama City and was a Master Diver with the US Navy serving in Vietnam (which was the "connection" of interest). D'Agostino has several interviews on line mentioning this research as "how he became interested in the ketogenic diet".

    Carry on...

    His interview with Layne Norton PhD, is what turned me onto his work. Its really interested.

    Yes, I happened to see that one. I'm not sure if it is because I stalk D'Agostino :) or because I subscribe to Biolayne (out of general interest) and a notification popped up on my computer. D'Agostino's research is interesting.
This discussion has been closed.