Oct 28

The Game of Glucose Part II

A couple months ago I showed how wildly different glucometers could be from each other and how this compared to lab results themselves in The Game of Glucose. At that time I wasn’t frequently taking glucose measurements within minutes of the actual blood draw for my lipid experiments. Fortunately, with my eye on the prize, I managed to wrap this last experiment into just such an exercise.

This time I tested glucose on both the Precision Xtra and Keto Mojo minutes after each blood draw. In fact, I had a deal with the lab that I could actually jump into an empty phlebotomy bay right after the draw to do my “extra homework.”

Full Disclosure

Before I begin, let’s get some disclosure out of the way.

  1. Like PTS Diagnostics, KetoChow, and Keto and Co – Keto Mojo has provided product and/or service in support of my research. While I ordered the initial kit on my own, they sent additional strips without any request on my part. As always with every company, I make clear the product support does not guarantee my speaking favorably of the company.
  2. Jimmy Moore promotes this product, and I will be speaking at the Low Carb Cruise next year at his invitation.
  3. As always, I do not accept any direct financial support or personal compensation of any kind from any business entity. I have been approached several times at this point for affiliate programs or direct advertising with this site and have had to turn them all away. This is primarily to maintain the integrity of the research as much as possible. I accept only funding by individuals.

In the case of Keto Mojo, I want to further concede that I instantly liked the owner, Dorian, when I met him at Low Carb USA before my presentation. He seemed particularly attentive to the Low Carb community and was clearly tailoring his products to this demographic. I told him I’d test his glucose/keto meter alongside the Precision Xtra and that I was “rooting” for him.

However, data is king. I told Dorian this in person and repeated it later in a Facebook message. I couldn’t say for sure if I’d keep using this product until I could see how it compares to the actual lab tests.

The Big Showdown

The experiment that uses this data will be a much bigger, more involved post. But this one component of it I can share now and it’s quite interesting. Below are three of the blood draws and the glucometer readings right afterward.

For the fourth test, I decided to go all out. I actually did four tests from the Xtra, four from the Mojo. Each of these pairings were from different fingers (right-hand index, pinky, then left-hand index, middle finger).

Okay, so let’s get this into a table to compare:

To be sure, this is a pretty small sample size at just seven data points. But that said, it’s a pretty strong endorsement for glucose accuracy on the Mojo side of the fence. The Xtra did have a couple spots where it beat out the Mojo against the lab results, but the two tests where it was off by -9 and -10 were certainly not encouraging by comparison.

Again, I’ll happily concede I was pulling for the Mojo as I hoped it would have comparable or better readings than the Xtra. But data is data. If these columns were reversed, I’d feel compelled to keep sticking with the Xtra on glucose testing. Fortunately, the Mojo delivered.

What Isn’t Covered

While this article ultimately compared the Xtra and Mojo regarding glucose testing, it didn’t touch on the other main front of ketones. Unfortunately, I don’t have an easy way to test this with my existing blood draw labs given their ketone readings aren’t very precise (I often get a “high” reading instead of a number). However, while not shown, I’ve found the Xtra and Mojo are generally within 0.1 of each other on ketone testing (in fact, just this morning it was 0.9 and 0.8, respectively). So overall, this is probably an avenue I won’t be pursuing much.



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28 Comments on "The Game of Glucose Part II"

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I was pulling for the KetoMojo because the strips are so much less expensive! =)

Geoffrey Levens

I have an Agamatrix Presto and did this same experiment. Did my own blood draw within a few seconds of the hospital lab phlebotomist. The Presto reading was 20 points higher!!!!! And still with the legal “range” for meters.

pip wood

I am in Australia and just beginning a series of tests of cheaper blood glucose meters on myself (diabetoc doing aip keto) and a superfit African friend (I have a scientific, part medical, data analysis background ) as I found wild variation. Even between fingers and teadings aplit seconds apart. We have a social enterprise project aimed at the 3rd world and are also not affiliated with any brands. I am so happy to find this site via a post on Mark Sisson’s keto site.

Aarn Farmer

Hello Dave,

I would like to invite you to be a guest on my podcast “My Sugar Free Journey” to talk about how cholesterol tests may be “hackable”. I have listened to one of your podcast guesting and I thought it would be a great idea to have you as well.

If you can, please schedule the best time that will work for you on this link: https://secure.scheduleonce.com/aarnfarmer
Here is my website: http://mysugarfreejourney.com/story/

If you have any other question, please reply to this email.

I hope to hear from you!

Aarn Farmer

Dr. Michael Ruiz

Looks good. I’ll consider the meter

Theresa romero

Looking forward to getting a meter.


I would like to compare as well since I have the Precision X.

Shannon gonzalez

Keto mojo alllll the way! Accurate and affordable


Yesss Wonderful

sue breshsear

yes I am l Looking forward to getting a meter.

Don Davidson

Enjoy this information! #whatsyourmojp #ketomojo Love to win this device!

Kathy Nutter

This was eye opening.


I Have entered to win this meter. my test strips are to old. I Need 1 really bad. Love to Try This One.

Jackie Cibulka

Who said the labs values were necessarily right? They have to calibrate their machines too? I just choose to believe in KetoMojo ☺️

Margaret R Brooks



I want the KetoMojo too for the same reason

Sandy Kaunisto

Keto mojo when science counts

Tim williams

I love my mojo for recording data

Tab T.

keto mojo


Im.learning so much

Jolene Miller

Would be nice to win one.


glucose meter comparison


I am on Keto diet and is in Ketosis. I have a Keto-mojo and a Bayer Contour glucose meter. I have collected more than 400 data points over a period of 4 months. And several lab test results. The data are amazing consistent: The glucose measured by Contour is consistently 20-25 points higher than those from Keto-mojo (100+ versus 80). The lab results seem to agree with the higher number: morning fasting glucose about 100. However, my HA1c (about 5.3%) suggests that Keto-mojo is more correct. Does anybody have more comparison data to indicate the accuracy of Keto-mojo glucose measurement?


I so would love to win a Keto Mojo meter! Have just used the AgaMatrix Presto up until now. I do love that it has an app.

Beth Daltonen

Awesome results for the Keto Mojo! I have been assuming the FDA approval would ‘secure’ both devices to be accurate. But this seems to be a difference indeed!
Here is another review of the Keto Mojo compared to the Precision xtra http://foodadviceonline.com/keto-mojo-compared-to-precision-xtra/

Beth Daltonen

Awesome results for the Keto Mojo! I have been assuming the FDA approval would mean the same accuracy for both devices. But It sure looks like the Mojo is ahead of the game! Here is another review of the Keto Mojo compared to the Precision Xtra.



Unfortunately you have not performed the appropriate stats for such comparison between the 2 meters. You should have used Root Mean Square Deviation calculation which would allow you to eliminate the problem of comparing positive readings (too high) vs. negative readings (too low) and assign them the same weight of error. In other words a reading too high like the 3+ reading on 10/17 is as bad as a reading too low and should carry the same error weight. The way you have calculated a simple average using positive and negative integers, 2 wrongs could cancel out each other and make it seem right.

Root mean square deviation calculation also gives more weight to, or highlights the errors that deviated greatest from the gold standard. As you stated, the -9 and -10 values don’t speak as strongly for the Precision Xtra meter. Mojo’s meter was not as far off of the gold standard lab values on individual tests compared to Precision Xtra meter and your stats can show this using root mean square deviation.

The calculation basically works like this:
1. Take the individual meter value differences and square them in a new column for each meter. This gets rid of the + and – signs.
2. Then Sum this new column that contains the square values for each meter.
3. Calculate the average of the sums (in this case divide the sum for each meter in step 2 by 7 (b/c you did 7 individual tests).
4. Take the square root of the averages of the sums for each meter.

This gives you the Root Mean Square Deviation for this example:
Percision Xtra meter’s root mean square deviation = 7.32
Mojo meter’s root mean square deviation = 3.74

Here is a website that shows you how to do this in excel if you care to look at it:

I came across your website via Amazon if reference to Ketone meter accuracy however seems you have not studied that variable. Thank you however for your attention to the glucose meter accuracy! Seems that people are not really understanding how their cortisol levels may be affecting their glucose readings and how quickly they can change based on time of day, light, fasting state. Basically cortisol and stress will pull more glucose out of the liver and will elevate your readings. I will search your website to see if you have given more info on cortisol for your readers elsewhere.

Thanks again.. Jennifer