Re: Feeling funny and burning...
There is a difference between ketonuria (ketones in urine) and ketonemia (ketones in the blood). It is ketonemia that is a secondary process of lipolysis... while ketonuria might be a secondary process of ketonemia. One can experience ketonemia without ketonuria... but ketonuria without ketonemia is not possible.
When Dr. Atkins explanained ketosis in DANDR, the explanation per se was consistent with ketonemia. However, as you read through the book, the two terms -- ketonemia and ketonuria -- are sometimes interchanged.
In the sentence you quoted above, by "ketosis" Dr. Atkins meant ketonuria. Ketostix measure the concentration of ketone bodies (more precisely, acetoacetate) in urine. Therefore, the darker the color, the higher the concentration of ketone bodies. So one could say that the darker the color of the stix, the higher the "degree" of ketonuria.
However, the color on the Ketostix is not proportional to the number of ketone bodies. On one hand because the body makes three ketone bodies -- beta-hydroxybutyrate, acetoacetate and acetone -- and Ketostix only measure the excess of one of them, acetoacetate. On the other hand because concentration is number/quantity per volume. Let's say you have 1000 excess ketones to pee, all acetoacetate. If you pee them in 1 L of urine, the concentration will be higher than if you pee them in 1.5 L.
As for the color on the Ketostix and weight loss... When fatty acids undergo beta-oxidation, they are broken down into two-carbon molecules called acetyl-CoA. For acetyl-CoA to proceed normally through the TCA cycle, oxaloacetate is required. However, when the intake of carbohydrates is low, oxaloacetate is shunted away from the TCA cycle and its carbon skeleton is used instead in gluconeogenesis. Without oxaloacetate, the liver has to find a different way to deal with the acetyl-CoA resulting from fatty acids oxidation, which is why it produces ketone bodies.
Beta-hydroxybutyrate and acetoacetate are the two ketones used for energy, while acetone is only a waste product of fat metabolism. In the body, acetoacetate can be converted to beta-hydroxybutyrate and acetone. Those cells that have mitochondria will take acetoacetate and beta-hydroxybutyrate and convert them back into acetyl-CoA, which then is pumped back into the TCA cycle. Excess acetoacetate is excreted.
Therefore, the concentration of ketone bodies in the blood (that is, the "degree" of ketonemia) is not proportional to the concentration of acetoacetate in the urine (that is, the "degree" of ketonuria). And it is the concentration of ketone bodies in the blood (ketonemia) that is a direct consequence of fat burning (lipolysis).
Furthermore, the fat "burned" in lipolysis can be either dietary fat or body fat. This is the reason why some people can be in ketosis without losing weight and inches. In an interview she gave a few years ago, Jackie Eberstein was telling the story of a patient she had at the Atkins Center who was gaining weight even though she was in ketosis (ketonuria). When asked about her menu, this lady told Jackie that every night after dinner she ate a whole stick of butter sprinkled with cinnamon. No surprise she was gaining weight!
Originally posted by jezzagirl19
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When Dr. Atkins explanained ketosis in DANDR, the explanation per se was consistent with ketonemia. However, as you read through the book, the two terms -- ketonemia and ketonuria -- are sometimes interchanged.
In the sentence you quoted above, by "ketosis" Dr. Atkins meant ketonuria. Ketostix measure the concentration of ketone bodies (more precisely, acetoacetate) in urine. Therefore, the darker the color, the higher the concentration of ketone bodies. So one could say that the darker the color of the stix, the higher the "degree" of ketonuria.
However, the color on the Ketostix is not proportional to the number of ketone bodies. On one hand because the body makes three ketone bodies -- beta-hydroxybutyrate, acetoacetate and acetone -- and Ketostix only measure the excess of one of them, acetoacetate. On the other hand because concentration is number/quantity per volume. Let's say you have 1000 excess ketones to pee, all acetoacetate. If you pee them in 1 L of urine, the concentration will be higher than if you pee them in 1.5 L.
As for the color on the Ketostix and weight loss... When fatty acids undergo beta-oxidation, they are broken down into two-carbon molecules called acetyl-CoA. For acetyl-CoA to proceed normally through the TCA cycle, oxaloacetate is required. However, when the intake of carbohydrates is low, oxaloacetate is shunted away from the TCA cycle and its carbon skeleton is used instead in gluconeogenesis. Without oxaloacetate, the liver has to find a different way to deal with the acetyl-CoA resulting from fatty acids oxidation, which is why it produces ketone bodies.
Beta-hydroxybutyrate and acetoacetate are the two ketones used for energy, while acetone is only a waste product of fat metabolism. In the body, acetoacetate can be converted to beta-hydroxybutyrate and acetone. Those cells that have mitochondria will take acetoacetate and beta-hydroxybutyrate and convert them back into acetyl-CoA, which then is pumped back into the TCA cycle. Excess acetoacetate is excreted.
Therefore, the concentration of ketone bodies in the blood (that is, the "degree" of ketonemia) is not proportional to the concentration of acetoacetate in the urine (that is, the "degree" of ketonuria). And it is the concentration of ketone bodies in the blood (ketonemia) that is a direct consequence of fat burning (lipolysis).
Furthermore, the fat "burned" in lipolysis can be either dietary fat or body fat. This is the reason why some people can be in ketosis without losing weight and inches. In an interview she gave a few years ago, Jackie Eberstein was telling the story of a patient she had at the Atkins Center who was gaining weight even though she was in ketosis (ketonuria). When asked about her menu, this lady told Jackie that every night after dinner she ate a whole stick of butter sprinkled with cinnamon. No surprise she was gaining weight!




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