Keto 101: Everything You Need to Know About Ketone Testing

Bret: 
This is Metabolic Mind Bitesize. I’m Dr. Bret Scher. So, you’ve started a ketogenic diet. You’re limiting the carbs. You’re eating the healthy fats. But one question may be bugging you: am I doing it right? Am I actually in ketosis? Today, we’re talking about ketone testing. The what, the how, and the when.

So, let’s kick it off. So first, why do we test? Essentially, I guess for two reasons. One, to see if you’re in ketosis, and two, to see how deep in ketosis you are. Now, what’s interesting is a keto diet is really the only diet that can objectively tell you if you’re doing it right, and I put “right” in air quotes.

There are many versions of a keto diet, but the goal is to allow your body to switch from burning primarily glucose for energy to burning primarily fat for energy, and in the process, creating ketones. So, testing is a great way to see if you’re accomplishing that goal. But perhaps the first and most important question is: does the level of ketosis even matter?

Should we care how deep in ketosis we are? Now, if someone’s using ketosis for general weight loss or metabolic health, maybe not. Being in ketosis is usually enough, and they can follow their lab markers, their body composition to see how they’re doing. Some may find better results with deeper ketosis, but often not.

But if someone is using ketogenic therapy to treat a psychiatric or brain-based disorder, like depression or bipolar disorder, the specific number can be vital for the therapeutic effect, okay? And that’s going to vary. And we have another video that talks about what level people might want to shoot for.

Okay, but now, what about the how? How do you test? One common starting point is using urine strips. You pee on them, they change color, and you match it to the bottle. These are great for a rough idea in the first few weeks or months, but here’s the catch. First, they’re not super specific for the level of ketosis, and second, they measure excess ketones your body’s peeing out. So, many people find that as you become keto adapted, meaning your body gets better at using ketones for energy, the strips often stop turning dark. So, they can lose accuracy over time.

And surprisingly, I haven’t yet seen any research on this. But regardless, it’s a common finding among users. So, urine strips are relatively inexpensive and can be directionally helpful early on, but limited for accuracy and long-term use. Okay, next up: breath monitors. These measure the acetone in your breath, and you just take the little thing, you blow into it, and it gives you a reading.

So, the pro, no finger pricks. No per-use cost. You buy the device once, and you can test 50 times a day if you want. But the cons, the devices are expensive upfront, and in my view, this is still emerging technology. Accuracy can be hit or miss depending on the brand and even how you blow into it, right?

Your technique can vary. It’s cost-effective for frequent testers, but keep that accuracy limitation in mind. And then, we have the capillary or finger stick blood monitor. This is, I guess for home use, is the most accurate way to measure the depth of ketosis. It measures beta-hydroxybutyrate, the primary ketone in your blood.

So, if you and your clinician have decided on a specific therapeutic range, say 1.5 to 3 millimoles per liter for treating cognitive impairment or depression or something like that, this is likely the tool that could be most helpful. But the cost can add up. The strips can be expensive over time. And yes, you have to prick your finger.

So, it’s the presumed gold standard, aside from going to the lab and getting a blood draw. But it requires buying the strips and not being too pain-averse to prick your finger. All right, so what about the future? Continuous ketone monitors, or CKMs, are available in some parts of the world, but not yet in the United States.

When these become more widely available, they could be a game changer. Imagine seeing how a specific meal or a workout or lack of sleep affects your ketone levels in real time all day long without ever needing to prick your finger. So, stay tuned for those. I think they’re going to revolutionize how we track ketosis and metabolic health.

So, that’s how to test. But what about when to test and how often? And honestly, the answer is: it depends. If someone’s just starting, testing once in the morning can really help see if they’re on track. But again, if they’re managing a brain-based disorder, they might test multiple times a day to see how stress, sleep, and food affect their ketone levels.

Plus, we know ketone levels vary during the day, even if nothing else changes. It’s rarely ever a straight line. So for some, it may help to understand their highest and lowest readings and see how that impacts their mood, their memory, and so forth. As for the timing, many suggest testing upon waking in the morning ,and again before their biggest meal. Although of course, after meals can be helpful for some to see how someone responds to that food.

So again, it comes back to your goals when determining how often and when to test. But here’s an important point. Don’t let this make you dizzy with all the decisions and the testing. Testing ketones is a tool that should help you feel empowered and in control of your keto journey. If it crosses the line to anxiety-provoking or obsession, maybe it’s not worth it.

And when in doubt, a consultation with a keto-trained health coach or dietician can be incredibly helpful. And we have a list of directories at metabolicmind.org that can be a good place to start. And if you’re interested in learning how others have used ketogenic therapy to improve their health and some of their specific tips, like when and how often to test, what levels to shoot for, you can find their profiles at metabolicmind.org/thinksmart.

So, thank you for watching. I hope this was helpful. if it was, please like and subscribe. And if you have further questions that I didn’t cover, please let us know and we can cover those in a future video or even in a Metabolic Mailbag episode down the road. I’m Dr. Bret Scher. We will see you here next time at Metabolic Mind, a non-profit initiative of Baszucki Group.