The relation of breath and blood ketone bodies - some weeks of testing

(German Ketonian) #1

I have been collecting some data over the course of the last 1 /12 months and measuring my breath and blood ketones. Since I don’t own a Ketonix,I used the AT6000 (https://www.amazon.de/gp/product/B01MQGBVB8/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1) and the Keychain (https://www.amazon.de/gp/product/B00IVFS01W/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1) breathalyzer for the acetone assessment. The correlation between the two is high (.65) but not perfect. Thus, I two different bivariable graphs to show the β-Hydroxybutyrate’s (BHB) relationship with my breath readings.

Overall, I collated 52 data points (so far—I will keep gathering data) every morning immediately after getting up. This makes for sufficient data to be somewhat statistically significant. I also collected my calorie and macro intake for the time. I will cross-reference them with this data at another time—this also should reveal some interesting patterns!

General data properties:

  • AT6000-measured acetone vs. BHB = 0.218516

  • Keychain-measured acetone vs. BHB = 0.269507

  • Average BHB = 2.259615

Here are the corresponding graphs for the AT6000 and the keychain device:

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Some thoughts on this:

  • Overall I think Jimmy Moore is right: there seems to be little point in trying to correlate breath and blood ketones as they are different ketone bodies.

  • Yet the correlation is surprisingly high if you consider the following idea: BHB is the storage of ketone bodies in your blood ready to be used, while acetone is more an indicator of what is being used at the moment of measurement. Then, you could even pose the hypothesis, that there is a negative relationship between the ketone bodies.

  • I’ve noticed some pattern: If a ate many calories and much fat the day prior to measuring (> 4000-5000 Cals, 80-85% fat, which is my usual ratio), BHB and acetone tend to correlate more strongly, that is I am using and storing ketones at the same time. When I am fasting, blood ketones tend to be high while acetone tanks (usually after 24 hours). If I ate regularly the day before (< 3000Cals, 80-85% fat), acetone is usually higher than the BHB value would give away. I am still looking for an explanation of this pattern

  • The usual grain of salt: it’s just N=1, folks!

Test Breath Ketones without a Ketonix (using a cheap breathalyzer)
#2

I am so grateful that there are data geeks on this site!
Thank you for sharing so that we may all learn.

#3

Just curious. On your fasting days , when you say your acetone tanks, would you say your activity drops enough to account for the decrease in bhb being burned and therefore the decrease in the acetone waste product? Or am I not understanding the process?

(German Ketonian) #4

Excellent question! I’d say no, my activity level pretty much stays the same. Otherwise, you’d be right: Then my body wouldn’t use as much ketones due to energy expenditure. No, this has to do with something else… my explanation so far is that my body attempts to conserve energy as I do not have huge amounts of fat (I am quite lean). I also do 48h fasts max, so on hour 60+, it could be that this phenomenon is no longer observable…

(Todd Allen) #5

I think the reason BHB rises and acetone drops during fasting is that muscles and some other tissues transition more towards using fatty acids directly, sparing ketones for the central nervous system which can only run on glucose or ketones. This reduces the need for glucose production through gluconeogenesis which without dietary protein consumes the body’s protein, mainly coming from muscle. The percentage of energy the CNS derives from ketones increases when serum ketones rise and serum glucose falls.

(German Ketonian) #6

Now that sounds interesting and cogent! My muscles regularly are in glucose-refusal mode as I “suffer” from adaptive glucose sparing aka physiological insulin resistance

#7

Fascinating and thanks for the answer.
One more stupid question , do you have any idea of approximately how much energy ( calories) we use in the digestion process? I’m trying to understand some weird anomalies I’m seeing while doing IF.
I appreciate your knowledge and scientific approach.

(German Ketonian) #8

I would venture the guess that it depends on your degree of keto adaptation and your intake of fiber. I have noticed that my body has a harder time digesting butter as opposed to olive oil. Additionally if I eat a lot of nuts (fiber) it seems my body doesn’t make use of all the calories I consume. I assume much energy is spent on titrating the energy out of all the fiber if that makes sense…

(German Ketonian) #9

I can literally eat 100-200g of plain butter in addition to my standard diet and not put on weight. That’s not the case with oil interestingly. So not all fat is processed equally and more calories are used or just “omitted” during digestion

#10

Thanks so much Zimon. Along with your glucose sparing idea helping me to understand my fasting glucose numbers creeping up over time, you made me realize I haven’t taken into consideration the fiber side of my almonds, walnuts and pistachios I love so much. I’ll have to go back to my food logs and glucose data but I think you may have shed some light on other puzzles.

(German Ketonian) #11

Great! Glad I could help!