Two Ten Day Fasts Last Month

Last month (March ’17) I did two extended fasts. I separated the two fasts by four days. The fasts were both ten days.

I tracked a bunch of numbers during the last fast including my Blood Ketone levels. I bought a Precision Xtra meter to measure Blood Ketones. The meter cost $25 on Ebay.

The meter comes with no strips. The strips are really expensive, at about $3 a strip. They are more accurate than any other home method of measuring Blood Ketones.

Blood Ketone numbers greater 0.5 indicate that you are in Ketosis. I saw numbers as high as 6.8 while doing extended fasting. Most non-fasting days I get values around 2.0.



Ketonix Notes

The Ketonix 2017 model that I recently purchased has been disappointing. Previous year models seemed to work better for others.

Seems that the reason they were better was that the previous models used a different unit of measure and produced a wider range of “normal” Ketogenic readings.

The new scale is in PPM which is a lower scale than the previous model used. From the article: Measuring breath acetone for monitoring fat loss: Review

In normal healthy individuals, BrAce can range from 0.5 to 2.0 ppm. Adults on ketogenic diets (e.g., high fat with low carbohydrate) can have elevated levels of up to ∼40 ppm.

The article includes a graph which has the same data:

This actually correlates to what I measured with my Ketonix. I got numbers from 4 (in Ketosis) to 22 (when fasted 10 days).

That correlates to the scale above which shows a Ketogenic Diet in an adult to go from 2 to about 40.

The problem is that the middle of this Ketogenic Diet scale is 10. It took me several days of fasting to get to this level. So for normal Ketogenic dieting there’s not enough scale to blink the colored LEDs on the unit. If you look at the fasting scale you can see I never reached the higher levels I should have been seeing at 10 days into a fast.

Seems like the unit sort of works and sort of doesn’t work. If it is accurate for PPM then I would never see a number above 50% if I was at the very top of the Ketogenic diet scale – which is not realistic.