Why I stopped checking blood ketones in the PM

photoAfter a little over two weeks of checking both AM and PM blood ketones, I found that my evening numbers didn’t correlate with my AM numbers.

The primary culprit I suspected was how close in time my last meal was with respect to the time I was checking my PM numbers.

Including transit times, we know it takes around 2 hours to digest simple carbohydrates from the time they hit your mouth to the time the last bit has entered your blood stream (that’s why they ask diabetics to check 2 hour post prandial blood sugars).

We also know that part of the reasons for the increased satiety we feel on a ketogenic diet are the fact that when we eat fats and proteins, these actually slow down digestion and require more time to process.

How much more time?

This is the question that I haven’t found an answer to. Here is a separate forum thread I found where people discuss this.  This corresponds to what I’ve seen other people report that it takes around 4-6 hours to digest fat and proteins.  I’d be interested to see some actual sources for this though.

But assuming this is true, assuming you eat a ketogenic meal high in coconut oil and other fats and proteins, your body will be processing these macronutrients from the moment it hits your mouth to at least 4-6 hours out.

I suspect that this is the cause for the discrepancy in ketone readings between PM and AM readings. The PM readings can be affected by the ketones generated by something that was eaten 6 hours ago!

The entire purpose of measuring blood ketones is to gain insight as to what metabolic fuel your body is preferentially using, fats or carbs?  A higher ketone number tells you that you’re metabolizing fats as the primary source of fuel.  But if this number can be confounded by something that was ingested up to 6 hours ago, it can’t be relied upon to provide an accurate representation as to the state of your metabolism.

This is something that definitely bears more looking into.

One Response to Why I stopped checking blood ketones in the PM

  1. […] the exception being that I stopped checking my evening ketones and blood sugars (you can read why here), and recently I added in my body circumference […]

Leave a Reply

Disclosures: Please note that some of the links provided are affiliate links, and at no additional cost to you, I will earn a commission if you decide to make a purchase.  Please understand that I have experience with all of these products.  If they're books, I've read them cover to cover, and if they're products or supplements, I've used and/or continue to use them, and I am not shy about giving my honest opinion of them, positive or negative.  The small commissions I make help me out a tiny bit, and if you've found my site helpful then feel free to purchase these products through the links I've provided.  If not, that's fine too, no pressure, I'll still continue to write!  Please do not spend any money on these products unless you feel you need them or that they will help you achieve your goals.

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites

Medical-Legal Disclaimer:

This site is not designed to and does not provide medical advice, professional diagnosis, opinion, treatment or services to you or to any other individual. Through this site and linkages to other sites, bjjcaveman.com provides general information for educational purposes only. The information provided in this site, or through linkages to other sites, is not a substitute for medical or professional care, and you should not use the information in place of a visit, call consultation or the advice of your physician or other healthcare provider. BJJ Caveman and bjjcaveman.com are not liable or responsible for any advice, course of treatment, diagnosis or any other information, services or product you obtain through this site.

Privacy Policy

See the bjjcaveman.com privacy policy here.