[quote="MonsterTruck, post:679, topic:9450, full:
I am very curious if there is a direct correlation between the number on the breathalyzer vs blood BHB levels.
[/quote]
The simple answer to this question is:
There is no correlation between Acetone levels and serum BOHB levels
That was my impression.
Personally, I’d also be curious to know how serum levels of each of the three ketone bodies correlated with breath and urine levels. And how each correlates with the other two in the same medium.
Paul,
I think that I am the forum member you are referring to.
All I ever said basically was that Breath Acetone was a slightly lagging measure of the extent of recent burning of Ketones.
I “never” said:
I “never” would say that.
Blood Ketone levels are just that: A measure of BOHB in the Blood; this is not an indication of being in Ketosis.
Theoretically, one could take 2 double whiskeys at night in the knowledge that one’s BOHB level would at least remain static overnight because the liver must immediately turn to neutralising the alcohol first which necessitates the suspension of lipolysis while alcohol remains in the system.
Acetone escaping through the lungs is a better indicator of the current state of Ketosis
And @PaulL congrats on becoming an Admin. Your dedication to the forum is exemplary.
“Class 1 registered medical device;” is a term used to make it seem like the item has been tested by the FDA and meets some standard. The reality is that class 1 devices require very little paperwork and a minimal fee to be registered. All that class indicates is that the device will, most likely, not cause any harm to the user. Band Aids are class 1 medical devices. The FDA never sees the actual device and does not do any testing of any kind on it. That is just a marketing gimmick to try to add credibility to a product.
All I know is the Ketonix folks never seem impressed when I post on their facebook adds about using a cheap breathalyzer. 
I am pretty sure they have nearly the same sensor hardware.
I bought a cheap breathalyzer on Amazon. I think it’s not reliable and not very accurate. Thus, I don’t think the numbers displayed on the readout necessarily represent an accurate ppm acetone, however, I think the numbers can be used to determine trends. For example, if the numbers rise over time, I think it is accurate to conclude that more fat has been burned; if the numbers fall over time that less fat has been burned; if the numbers remain steady over time that more or less the same amount of fat has been burned.
I posted the following elsewhere but think it’s good idea to post it here, too. Although I have seen various attempts to correlate acetone and BOHB, the most successful seem to be scatter plots, I don’t really think there is any direct relationship between the two. They measure different things:
Glucose and ketones in your blood are available fuel. Acetone in your breath is the exhaust gas of fat burning. So if you want to measure fat burning, measure acetone concentration in your breath.
Why use such an indirect method when you can just see how your clothes fit, how you’re looking and what you weigh?
The belly ( not the waist ) circumference is as accurate as you can get. better, faster, and cheaper than DEXA.
I have one and the numbers definitely rise when I am fasting and would drop to zero when I ate too many carbs, so a cheap way to monitor your ketones.
However - it cannot differentiate between burning plate fat and body fat. If you are fasting then by default body fat. But if having a BPC while still calling it a fast or eating your normal amount of fat - could be either.
Other than fasting to eliminate ‘plate sourced fat’, I agree. So as you say, it’s just a quick, easy and painless way to take a snapshot of fat burning or determine a trend over a period of time without purchasing a Ketonix. Or a Levl which is more than double the cost of the Ketonix, but probably the most accurate system available.
As for relevance, I think many people start on keto to lose weight and would find it very helpful to determine whether they are actually burning fat and relatively how much. Many posters on this board express their discouragement because they aren’t losing as much weight as fast as they think they should. They might become less discouraged to know they can actually measure fat burning directly with a cheap device and painless procedure.
I have a friend who is losing weight and having DEXA scans done periodically to track elimination of body fat. She forwards copies of the scans to me once in a while because I’m interested in the procedure. I find it implausible that measuring your belly circumference with a tape measure is more accurate. Cheaper, faster, yes. Better, no.
Sure, if you don’t/can’t afford the DEXA scans measure your belly circumference. Do so anyway just for encouragement of knowing it’s decreasing.
I exaggerated .
I should have said belly circumference is a good indicator and shut up.
thanks for bringing me back to my sense.
I don’t know what all the fussing is about … I bought the AT6000 and it works like a charm. In fact I am confused by all this blowing and counting you are all talking about 6 seconds, 10 seconds etc … My device read immediately … I’m not keto adapted or anything, I just got it to track my fast so I know if I am in the danger zone … done two days of mild keto (first time for me eating keto) reading 0.00 third day began fast reading went from 0.02 to 0.03 second day fasted reading went from 0.04 to 0.05 and 0.06 back to 0.05 over the course of the day … today when I woke up it was 0.10 but after doing so activity, it came back down to 0.06 … so here get this, over the last few days I didn’t have to blow for any length of time, my at6000 takes a reading in 1 second or under … I think you are all breathing wrong? I alter my breath so that I have just breath’d out normally as the blow now signal appears or beeps and then I just breath into it with hardly any pressure at all ,very lightly, like when you are fogging up a window or mirror with the heat of your breath and it take a proper reading in less than a second, that’s it , there is no 10 second blow required … I just though I would let you all know my experience with this … I really enjoyed reading this thread, thanks
I bought the AT6000 and couldn’t get it to read anything. In the meantime I stuck to measuring blood ketones with my PrecisionXtra. Then I caved in and bought the Ketonix. I definitely like the fact that I’m not pricking my finger all the time. But I don’t trust the results as much. For those of you who use a Ketonix, what level do you consider to be indicative of a good level of ketosis? From the way it is set up, it seems that 4ppm is the goal. That seems low to me. 10 seems more reasonable. I’ve sort of come up with my own rule: If the dial starts moving while I am still blowing, then that is good. If not, I’m likely not in ketosis. I would love to hear how others are interpreting their Ketonix readings.
Ok I noticed as I finished my fast and for several days after, the time it took to read and register a result took longer and longer requiring a longer blow before beeping … So it does seem to read properly when saturated with ketones but for people who are fat adapted or keto adapted they might have much lower levels due to utilization of their ketones and thus reading requires longer blows or may provided lower BAC results much the same as the keto strip urine problem after months of adaptation …
I got a cheap one too, it says it measures in mg/l which as I understand is equivalent to ppm. My readings are .2 - .25 problem is I can’t find a chart that tells me for sure where I am. Too many conflicting charts and converting is a problem. Can you tell me, pete, in mg/l what the ranges are??? I don’t know why I can’t determine this definitively on the internet. IT’s driving me crazy.
TIA
Pi
To ANY and ALL who are using a “Cheap Breathalyzer” please be advised these devices DO NOT give you any relevant information about anything. Period. Nothing. Nada. Zilch. Zip. Do not fool yourself thinking otherwise. Stop posting meaningless numbers and asking for advice about them. Please! You’re just giving blood donors more justification to denigrate breathalyzer sampling.
And don’t think my results reported below were due to my specific cheap device and that your cheap device is different. It’s not. It’s a cheap alcohol breathalyzer that by a fluke of sensor design does not distinguish acetone from ethanol. It might measure ethanol accurately, or not. If you want to measure BrAce accurately, get a Ketonix. Or, there is another product due out “real soon now” called Keyto.
Please stop already. This dead horse has been beaten to a pulp. Have fun if you want to, but don’t post meaningless numbers. Thank you in advance.
That’s a pretty strong post to someone’s first post. It’s not like they have been here long enough to read any history - they just asked a simple question. Sheesh.
Hi Piwacket and welcome to the forum!
I played around with my cheap breathylizer when I got it and it was fun. The numbers don’t mean anything or correlate to blood ketones but I used it a lot on multi-day fasts and the numbers would steadily rise the longer I was fasted so it trended with my higher ketones.
I also would blow “0” when I knew I had too many carbs so can be a quick check for that also. I found if I held my breath before I exhaled that it would read a bit higher. I guess you are concentrating the acetone in your lungs.
I finally broke down and bought a Keto Mojo and test when I am fasting more than 36 hours so don’t use my breathylizer any more.
But if you are getting something more than zero and haven’t had a cocktail LOL then you are doing just fine.
