Why it’s Important to Test Both Glucose and Ketones on Keto

Published: October 2, 2020

The Balance Between Ketone and Glucose Levels

I want you to imagine this for a second, you measure your ketones, and you have a relatively low level of ketones that you measure. So you get frustrated, you want to throw in the towel cause you think, I guess I’m not doing the ketogenic diet properly. Well, I’ll tell you that’s a very common thing that people encounter. We have to remember one very, very, very important thing. Your level of overall ketones in the blood, isn’t always the main thing that you should be looking at. There’s a balance between the level of ketones and the level of glucose. Alright, so first off, let’s look at the means of testing ketones first, okay. There are three primary ways that people will generally test their ketones.

Testing with Urine Strips

Okay, the first one is one that you’ve probably done before, okay, those little urine strips. Now when you utilize the urine strips, you’re measuring something called aceto-acetate. And aceto-acetate is one of the three primary ketone bodies. However, when you use those urine strips, you’re measuring excess ketones, okay? So what that means is that when you first start a ketogenic diet, you generally have a large excess of ketones because your cells, your mitochondria, hasn’t become very efficient at utilizing them yet. So yep, you urinate on the stick, and you get all excited because you’re high in ketosis. Well, next thing you know, two, three weeks go by and you’re not registering as many ketones. So you start to get frustrated, you start to think that, you’re not getting an effect or the ketogenic diet isn’t working for you. Well, that’s simply because your cells are getting adapted to the ketones. So you have less excess ketones circulating the bloodstream and ultimately ending up in the urine.

Testing with Breath Meters

Okay, now let’s look at the other piece. Okay, you’ve got breath acetone. Now breath acetone is a viable way to measure, except for one big glaring issue, okay. Usually, acetone is a byproduct of aceto-acetate for lack of a better term, self-destructing in your body. Which means, that that’s not the cleanest way to get a ketone reading. Although it does provide you with some data points.

Why is Blood Testing the Most Accurate?

When it comes down to measuring, blood is going to be the end all be all. It truly is the gold standard because regardless of your level of fat adaptation at the cellular level, it is truly going to tell you the amount of beta-hydroxybutyrate, which is really the active ketone that we want to measure and see where it is in the bloodstream and how it could be impacting the cells at that level. Okay, now let’s expand a little bit further, and let’s look at something called the Glucose Ketone Index. Because in that same vein, if you measured your blood, being the gold standard of measuring ketones, and you find that your ketone levels are a little bit low, it’s easy to once again want to throw in the towel because you’re not achieving this high number of ketones. But that high number of ketones, isn’t the biggest piece, because we have to look at how glucose, is in the equation as well. You see, when you have ketones and glucose in the bloodstream, your body is always going to preferentially use what there is more of, okay. So if you are tilted towards more of the scale of glucose, your body is going to use more of the glucose, even if there are some ketones present, and vice versa.

What is the GKI?

So that’s why you look at what is called the GKI, which is a simple mathematical equation of dividing your glucose level by your ketone level. And this gives you your GKI. So let’s talk GKI for just a second. Why GKI was really first looked at? Okay. It came down to cancer research. That’s why this whole thing started with GKI, okay. They found that brain tumors generally were responding to an abnormal form of what is called anaerobic glycolysis. And I’ll spare you all the scientific details. But basically, it just means that specific brain tumors were utilizing sugar or glucose for fuel when they really shouldn’t have been, and it all had to do with the fact that they were operating inefficiently because cancer cells usually have mutated mitochondria. They have like a mutated way of creating energy. So, scientists realized that if they measured ketones, and they measured glucose, they could get a better indicator of when a cancer cell was starving versus when a cancer cell was thriving. So carry that over into how we might use it.

What is Relative Ketosis?

Well, we start to determine when is our body utilizing ketones, much more efficiently than glucose, I’m going to give you an example here for just a second, if I were to go out for a run right now and run some sprints, there’s a very good chance that my ketone levels are going to drop, okay. That could imply that I’m not in a very deep state of ketosis. But what I like to call it, is a relative state of ketosis. Because I just worked out, there’s also a very good chance that my glucose levels may have dropped because my body utilized that glucose a little bit more. Now, there’s also an opportunity for my body to elevate glucose levels, but we’ll save that for another day. The point is, I’m still in a relative deep state of ketosis, based on my level of ketones and my level of glucose. Another simple example just to give you random rough numbers. So if I have one millimole of ketones in my blood, and my blood sugar is giving me a reading of 60, that’s a pretty good ratio of low glucose to relatively high ketones. Now in that same equation, if I have that same amount of ketones, one millimole, but my blood glucose is 100 or 110, obviously, that’s a much different ratio. But if you’re looking at ketones only, you’re going to say, “Hey, I’m deep in ketosis. “I’m doing fine. “This is exactly where I want to be.” So hopefully, you can see how measuring your glucose along with your ketones is really, really important.

Why it’s Important to Test Both Ketones and Glucose

Another reason why it’s really important to not just be testing your blood ketone level but your blood ketones and your glucose levels is to really gain an understanding of your response to a given food. Okay, consider this again for a second, you just consumed a small piece of bread, just a small piece and you’re on a ketogenic diet, well, that’s going to skyrocket your blood sugar, even a little bit because your body is not adapted to it. But your response to a given food might be different from someone else’s response. See, there are various levels of what’s called Peripheral Insulin Resistance, all kinds of things that I could go down various rabbit holes with. The point is, different people will respond differently to different foods, that’s right. Even on a ketogenic diet, some people can get away with eating a small amount of carbohydrates, because their body utilizes it differently, and doesn’t cause as much of a spike in blood sugar. So it ends up giving you the tools that you need to be able to eat the foods that you want to eat, or can eat, and really stay within that healthy range. Another thing to consider, is just like I mentioned earlier, is exercise. Sometimes you don’t realize how a particular exercise impacts your ketone levels, and if your goal truly is to maintain a high level of ketones, or at least a nice GKI, then you want to know what kind of exercise triggers what within your body.

What Does Stress Do To Your Levels?

And then of course we look at stress, okay. One person could be very stressed out, and they measure their ketones, and they find their ketone levels have dropped. So they get frustrated, and they feel again that their stress is ruining their ketogenic lifestyle and they shouldn’t do keto because of that. But if you were to look at the big picture, you might see that your overall levels aren’t as bad as they seem. On the contrary, if you’re just measuring glucose, it would be easy to say, “Oh, I’m stressed out, “so my glucose levels went up,” because epinephrine when you’re stressed out, will trigger your glucose levels to go up. But one thing that people don’t think about very often, is that epinephrine, which is released when you’re stressed out, also releases and liberates fatty acids. So that means that, that could be elevating your ketone levels too. So the point is even if you measure your glucose and you’re reading 100, or 110, you don’t want to get discouraged unless you’re actually looking at your ketones too. Because there’s a very good chance your ketones have gone up with stress too, simply because they get created by the fatty acids being liberated, as a result of the epinephrine.

The Whole Picture

So look at the whole picture, you are your own data point. You want to make sure that you are looking at all factors that you can make the best-educated decision on your diet, on your exercise, on your stress level, on your sleep, and overall who you are as a person. So we need to be leaving the guesswork, out of the equation. We need to lean on the gold standard of testing. Leave the measuring to the meter, the Keto-Mojo GK+ Meter that measures your ketones and your glucose.


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