That's interesting and affordable too.

I'm interested in what the veteran keto folks have to say.

I found this study that says breath acetone is a reliable indicator of ketosis in adults consuming ketogenic meals. It's not a long-term study though, but still intriguing.

http://ajcn.nutrition.org/content/76/1/65.full

Which breathalyzer did you get from amazon?

That's interesting and affordable too.

I'm interested in what the veteran keto folks have to say.

I found this study that says breath acetone is a reliable indicator of ketosis in adults consuming ketogenic meals. It's not a long-term study though, but still intriguing.

http://ajcn.nutrition.org/content/76/1/65.full

Study compares breathalyzer with Urine strips. I would love to see studies comparing with blood BHB levels to acetone levels. I can save a lot of if they are comparable.

Ok, guys I borrowed a breathalyzer from some one I know. Its pretty useless because it measures acetones not BHB. BHB >0.5milli molars is ketosis. Dang! I thought I could save some money getting rid of those ketone blood test strips.

For those who would rather buy it on Amazon I found the same one the op is using http://www.amazon.com/Digital-Breathalyzer-Blood-Alcohol-Tester/dp/B005K6HTTO/ I'm going to try it out once I run out of urine strips.

I'm new to nutritional ketosis, I got the urine test sticks, which said I was in ketosis, then I'd read that it's not that accurate, so I was looking at the other options, I'd like to do Blood, but cant afford to keep up that expense. So was looking at the ketonix breath tester but it's a lot of $ too, it's on my list though, in the end much cheaper than blood testing.
For now, I thought I'd try the Alcohol Breathalyzer, it was all of 5.95 with free shipping from ebay. I've consistently been blowing between 0.02 and 0.05 most every test. (0.00 when I know I'm over my carb tolerance) So it seems to be working.
However, I'd like to know if anyone has a chart or even a rough estimate of how that would correlate to blood ketone levels.

yarwell wrote: »

If you want to know the correlation with a specific device I think you'll have to splash out on 10 keto blood test strips for $20 or whatever.

In blood B-OHB is ~80% of ketone bodies, 18% are acetoacetate, 2% is acetone from spontaneous decomposition of acetoacetate.

Breathalysers measure acetone in breath, which will be related to blood acetone which in turn is related to acetoacetate from which B-OHB is produced.

Pee sticks (ketostix) measure surplus acetoacetate spilled out by the kidneys. You can be in ketosis by B-OHB and get a negative ketostix response :-

Yar;

Thanks for the "excellent" explanation and especially the graphic.

Couple of "minor" questions.

1. Don't disagree with "....acetone in breath which is in turn related to acetoacetate..." but am I correct in assuming that you do not mean to imply that the two are directly, and consistently related - mathematically, (as in X ALWAYS = Y?). I believe this to be the case (no direct mathematical correlation) but have no cite to verify - do you? (Not questioning your info but preparing for the "....me or your lyin' eyes" skeptics)
2. On the Ketonix - I'm color sensitive (blue/green) so not a good judge but my wife is not (she reads every stupid number on the circle joke-makes me crazy<g>) - and even she says it's almost impossible to differentiate between the "yellow" and "green" ranges, which renders the already questionable "scaled" readings pretty much useless.
   Do you see a clear distinction or might my unit be defective?

Thanks again for the post and if you don't mind I'm gonna hijack your "Pin" for future use (will credit, IF I remember who to credit <g> (not so easy these days).

I really don't "get" why there is so much resistance to just doing the B-OHB tests. Yes they "can" be somewhat more expensive but unless someone is conducting multiple N=1 tests there is no reason to test everyday. Especially when it IS pretty easy to determine an individual correlation between blood glucose level and k-ranges. $130 (ketonix) buys a lot of K-strips and 4 or 5 times that number of BG strips.)

Not to mention that, with the "right" meter, it's a "twofer" - BG and K in the same meter and BG numbers "might" be (are?) even more important for EVERYONE to monitor, at least occasionally {/soapbox}.

"breath acetone acetoacetate relation" is a productive search term in Google

This link is a short video of the startup mode of the original ketonix which shows the relative positions.

deansdad101 wrote: »

My bride, who runs 0.5-1.2 on a pretty consistent basis has YET TO register "anything" on the KN (never changes from solid blue, no flicks), after probably 25 attempts.

Get her to take a swill of wine and see if that wakes it up - the sensor is not specific to acetone.

miamouse3 wrote: »

Black_Cats_Rule wrote: »

For those who would rather buy it on Amazon I found the same one the op is using http://www.amazon.com/Digital-Breathalyzer-Blood-Alcohol-Tester/dp/B005K6HTTO/ I'm going to try it out once I run out of urine strips.

Please post if it works for you! I don't fancy the idea of those pee strips/sticks. My partner is iffy about me going Keto as it is lol. If it is effective, it will save me money and weird looks from her lol. I am starting Keto tomorrow, just bought *most* of my first weeks stuff.

I bought the same one (but with prime), here is the link:
http://www.amazon.com/gp/product/B00KL8XJEA?psc=1&redirect=true&ref_=oh_aui_detailpage_o04_s00

just today i did a pee test and scored somewhere between 40 and 80, then i used the breathalyzer and got 0.02%. I will run further tests and try and make some type of correlation between the two, perhaps I will invest in the blood meter to compare more accurately. hope this helps!

Update: after many days of using the cheap Greenwon, I still like it, but I got a second identical one to compare, and it reads quite different from the first. The first reads 0.02-0.04% when my blood ketones are over 1mmol, but the second consistently reads 0.00% unless I drink a couple of glasses of wine, so it looks like they have some kind of offset issue and a lot of manufacturing variability.

So I bought this one instead: http://amzn.to/1S9XyjU

It's a bit more expensive but seems to be a newer design and is definitely more reliable. It has a slightly longer 15 second warm-up time compared to 10 seconds on the cheaper unit. It has three sig figs of BAC %, so you get more fine-grained numbers like 0.036% rather than just 0.04%. It reads very consistently if you use it several times in a row and reads 0.000% if you blow just air through it.

Just started trying to get into keytosis and hadn't limited the carbs enough - was getting 0.0 on the cheap key-chain breathalyzer I happened to have - thought it didn't work - tried a bit harder yesterday to stick to the plan and today it reads between .04-.05%. Wow... it works. However I went ahead and ordered the blood tester and ~10 keytone test strips so I can get an idea of how the breathalyzer correlates for my body. Should be interesting. I'll post back when I have more info.

After reading this post I wanted to add a few thoughts that may assist other readers in purchasing a good breathalyzer and keeping the readings accurate. I regularly use and calibrate breathalyzers at work. Lack of calibration may be one of the issues you are running into when comparing readings from various breathalyzers. Especially using older breathalyzers, or breathalyzers that don't see regular use (lack of use increases the chance the breathalyzer will go out of calibration). We verify the calibration of our breathalyzers monthly and calibrate as necessary. Even the expensive ones that we use do go out of calibration from time to time. With that said, I was not able to locate a calibration process or calibration substance for some of the breathalyzers mentioned in previous posts. I, like others, am trying to find the most frugal method of testing, but I am willing to pay a bit more for accuracy. BACtrack recommends calibrating non-pro breathalyzers, like the keychain breathalyzer, every 6 months. The calibration for the keychain breathalyzer cost $19.99 or $40.00 per year, which nearly doubles the initial cost. The BACtrack mobile cost $99.99 and is considered a pro breathalyzer which requires calibration once a year, at a cost of $24.99. BACtrack's calibration test require you to send your breathalyzer back to the manufacturer, meaning you will be without it for the time it takes to send out, calibrate and return. We calibrate the devices at work ourselves using a calibration gas, greatly reducing down time compared to shipping out for calibration. While still less expensive than the blood meters for frequent testing, calibration is a hidden cost that should be considered if you expect your breathalyzer readings to stay accurate.

Just to clarify before the question comes up, I do not work for any company that produces or sells breathalyzers. Also, I do not use BACtrack at work. I mentioned BACtrack because it was the first breathalyzer I found that was both sold on Amazon and has a calibration method.

I was going to experiment with the breathalyzers but found this deal. Its a Nova ketone meter with two boxes(20) of ketone strips for less than $40. https://storefront.novacares.com/storefront/free-meter-w-purchase-of-2-boxes-of-ketone-strips.html if anyone is interested