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RHR: How to Accurately Measure Ketones, with Trey Suntrup


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If you’ve ever tried the ketogenic diet, you know how important it is to track whether or not you’re in ketosis—and how hard it is to accurately measure your ketone levels. In this episode of Revolution Health Radio, I talk with Trey Suntrup about the different testing options available for measuring ketosis, how much variability there can be [in] your ketones throughout the day, and a breath-testing device that can track ketosis accurately.

Revolution Health Radio podcast, Chris Kresser

In this episode, we discuss:

  • What nutritional ketosis is
  • The different types of ketone testing available
  • What the testing units mean
  • The daily variability of ketones and why you may need to test more often
  • How Biosense works

Show notes:

Hey, everybody, Chris Kresser here. Welcome to another episode of Revolution Health Radio. This week, I’m really excited to welcome Trey Suntrup as my guest. We are going to be discussing a new clinically validated device for accurately measuring ketones in the breath.

I’m really excited about this device, which is called Biosense, because as a clinician who uses ketogenic diets therapeutically with my patients, it has always been a challenge to get accurate ketone measurements. There are various methods to do this on the market from urine test strips to other breath devices to blood ketone measuring devices, but they all have issues, and for various reasons have not been very practical or helpful. So I’m using this device Biosense with my patients, I use it myself, and I want to tell you a little bit more about it because I know many listeners are interested in ketogenic or lower-carbohydrate diets.

Trey has a background as a researcher and a product engineer and has a PhD in physics and electrical engineering from UC Santa Barbara, is really knowledgeable on this topic, and I think you’re really going to enjoy this podcast. So, without further ado, let’s dive in.

Chris Kresser:  Trey, welcome to Revolution Health Radio.

Trey Suntrup:  Chris, thank you so much for having me.

What Is Nutritional Ketosis?

Chris Kresser:  I’ve been looking forward to this because, as you know, I’ve been using the Biosense device to measure ketones in my practice for some time. And it’s been a game-changer for me as a clinician because that hasn’t been easy to do. I mean, it’s kind of surprising given the popularity of the ketogenic diet, but all of the prior existing methods of measuring nutritional ketosis for people who are doing it lacked something or something else.

So before we dive into what makes this device such a game-changer, let’s just do a brief review of the basics for folks that might be a little bit less familiar with nutritional ketosis and the ketogenic diet. So what is nutritional ketosis just at a high level? And I can talk a little bit about some of the clinical applications that I use in my practice.

Trey Suntrup:  Yeah, absolutely. So, normally, in modern times with the Standard American Diets that we eat, we’re eating a lot of carbohydrate[s]. And what that means is that there’s a lot of glucose in your blood. So there [are] two primary fuel sources for the body. You can either be fueled by glucose primarily or fat primarily. And it depends on the macronutrient content in your diet, which of those is the primary fuel source for you. So, like I said, normally in modern Standard American Diets, there’s a lot of carbohydrates, so you’re primarily fueled by glucose and carbohydrate. Ketosis is when your primary fuel source switches from carbohydrate or glucose to primarily free fatty acids, and those are metabolized in your liver. And one of the byproducts of that metabolism in the liver, are these ketone bodies. These ketone bodies are released into your blood where they can serve as an alternative metabolic substrate to glucose. So nutritional ketosis is really, we speak of it as this very sharp transition. And in truth, it’s a gradual transition that occurs over, we’ll talk about units later, but several millimolar[s], tenths of millimolars, in your blood where you switch from primarily glucose metabolism to primarily fat metabolism.

Chris Kresser:  And ketones can be used by all cells in the body, but they are particularly liked, we could say, I guess, by the brain and the heart, right?

Trey Suntrup:  Yeah, that’s absolutely right. So it turns out that fatty acids directly cannot cross the blood–brain barrier. And that’s the reason that the brain cannot metabolize fatty acids directly. So ketones are necessary when you’re in this ketogenic state; when you have a deficit of glucose in your blood, ketones are required to fuel the brain particularly, and also they’re finding the heart. That’s absolutely right.

Chris Kresser:  So this definitely sheds light on some of the clinical applications of a ketogenic diet. Now, many people first hear about it for weight loss and metabolic health. So somebody has type 2 diabetes, for example, or pre-diabetes, metabolic syndrome. A ketogenic diet can help tremendously with weight loss, and it can also help to normalize blood sugar and insulin sensitivity and reduce blood pressure. There are a lot of good data on this now. We’ve covered it ad nauseam in lots of different contexts and I’ve spoken about it on Joe Rogan’s show numerous times. So I’m not going to belabor the point here. But [there’s] plenty of research now supporting a ketogenic diet as a weight loss intervention and to improve metabolic health. And we, of course, now have companies like Virta Health that are actively employing this strategy in the consumer and corporate market to help people lose weight and reverse metabolic issues, which is probably the number one chronic health problem that we face in this country.

So I think that’s how many people become familiar with the ketogenic diet. But then, of course, other clinical applications are more directly related to the role of ketones in the brain and the nervous system, which include things like Parkinson’s disease, traumatic brain injury, it’s being investigated, oh epilepsy, certainly both in kids and adults. It’s been a game-changer for [the] treatment of refractory epilepsy for kids, allowing them to get off medications, which can have horrible side effects. It can be used in cognitive disorders like dementia and Alzheimer’s [disease]. Apollo Health, which is Dale Bredesen’s clinic, is actively exploring using ketogenic diets for that purpose. There’s been research on nutritional ketosis as being beneficial for migraines, which can also be a debilitating condition. And I think we’re just kind of scratching the surface, actually, on what some of the therapeutic applications for nutritional ketosis might be.

But all along the way, one of the biggest challenges has been not just in the outpatient setting where people are doing ketogenic diets on their own and trying to figure out if they’re in ketosis, but even in research settings where studies are being performed to determine the impacts of nutritional ketosis, there’s been a real challenge with how to even know whether you’re in ketosis. So let’s talk about the available measuring devices or the ones that have been available historically. And then what [have] some of the challenges been with those existing technologies?

Trey Suntrup:  Yeah, Chris, do you mind if I say one more thing about the different treatment?

Chris Kresser:  Not at all.

Trey Suntrup:  The different ways that nutritional ketosis is being used to treat certain diseases? One thing that’s fascinating is I think everybody understands and recognizes now, or at least there’s a growing understanding of, how important nutrition and lifestyle [are] to health. I think that’s a basic truth that everybody appreciates. But what’s interesting that’s happening in medicine, even traditional medicine right now, is the degree to which these other conditions that used to not be thought of as metabolic diseases are now kind of getting reclassified as such, right? And you mentioned neurodegenerative disorders like Alzheimer’s or Parkinson’s [disease]. And those are now starting to be thought of a little bit more like metabolic disease[s] in the same way, not in the same way, but in a similar vein as diabetes. When we talk about gluten …

Chris Kresser:  Yeah, so some refer to Alzheimer’s [disease] as type 3 diabetes now.

Trey Suntrup:  Exactly, exactly. So that’s a fascinating trend that’s happening right now. And it extends even to things that are non-obvious, like oncology and cancer, right? There are certain types of cancers that respond very differently to chemotherapy, whether you’re eating carbohydrates or not. Right?

Chris Kresser:  Yeah.

Trey Suntrup:  So this reclassification of things, of certain disease states as “metabolic diseases,” and that kind of bucket of diseases is growing, which is fascinating.

Tracking your ketones is an important part of following a ketogenic diet. Check out this episode of RHR to learn more about tracking ketosis and to get a $30 discount on an accurate breath testing device. #keto #lowcarb #chriskresser

The Different Types of Ketone Testing Available

Chris Kresser:  Right, yeah. We are just scratching the surface, truly, and I think having an accurate, convenient, and reliable way of testing breath ketones, both in a research setting, or testing ketones, not just, breath happens to be the way that that’s playing out. But just any way of testing ketones conveniently and reliably is going to enable more research to be done. And for that research to be more reliable, and for practitioners like myself and then nutritionists, and health coaches who are out there working with folks to get better results, because they’re going to be able to have reliable data to process and use it as they explore this further.

So, yeah, please tell us a little bit about the existing technologies, [the] pros and cons, and why a new method was needed.

Trey Suntrup:  Sure. So I think if people are familiar with tracking ketones at all, they’re typically familiar with either blood testing or urinary testing. So we’ll start with the blood test. I think people understand that blood testing is an accurate way to measure the concentration of ketones in your blood. There is a little bit of a caveat there, which is that there was a study that found a discrepancy between the measured ketone concentrations in your blood depending upon where you drew the blood from.

So whether you use capillary blood in your finger, I actually did a full venous draw, there is a discrepancy there. So I just want to highlight that caveat. But of course, the disadvantage of that is that you have to prick your finger and draw blood. So that’s going to discourage a lot of folks from measuring at all if that’s the only way that they can do it.

In our clinical trial, which we’ll talk about a little bit later, we had a lot of folks tell us that it was a big deterrent, to prick their finger and do their blood ketones during the study. And people were running off to conference rooms at their work and setting out all their supplies, and it’s a bit of an ordeal because you don’t just need the blood meter, you need the strips and you need the lancet and all that stuff.

Chris Kresser:  And those strips can be expensive, too.

Trey Suntrup:  Absolutely. Absolutely.

Chris Kresser:  Especially if you’re doing multiple readings a day, which we’re going to come back to a little bit later in the podcast.

Trey Suntrup:  Exactly, exactly. So there’s a convenience deterrent, there’s a pain deterrent, and there’s an economic deterrent, as you mentioned, because there’s that disposable strip component that can definitely add up. So that’s really the blood ketone meters. I should also mention that several of the commercial blood ketone meters on the market also frequently have discrepancies if you compare them.

Chris Kresser:  Yes, that’s true.

Trey Suntrup:  Yeah, so I think there’s this perception among some that that’s sort of ground truth, but there’s a lot of caveats around that, some of which I already mentioned. So that’s blood ketones. Urinary ketones are interesting, because they’re not as invasive, obviously. Of course, they’re still not super convenient, because you have to run off to the bathroom anytime you want to do a measurement. And also, they’re not precise. So they provide you with a range of ketone values, and even that range is a bit suspect.

So one effect that people who have done the ketogenic diet have noticed is [to] think of urinary ketones as the excess ketones that your body is excreting, right? It’s sort of unused, unneeded ketones. And at the beginning, when you first start a ketogenic diet or you first start carbohydrate restriction, you are dumping a lot of those ketones into your urine. So your urinary ketones go up. But after your body gets used to using ketones, and is more efficient with the production and utilization of those ketones, your urinary ketones actually drop. So your body doesn’t need to excrete them, because it’s essentially gotten better at titrating the supply and demand of ketones in the blood. So it’s just not dumping as many in the urine.

So a lot of folks see their urinary ketones drop after several weeks of carbohydrate restriction. But the truth is, you’re still in ketosis; it’s just [that] your urine strips tell you otherwise. The other issues there are that urinary ketone levels are influenced by things like the level of hydration, how long the urine has been in the bladder, [and] stuff like that. So I think that combined with the fact that it’s the excess or unused ketones makes it less useful, particularly for a clinical setting where you really want that clinical-grade accuracy.

Chris Kresser:  What about some of the other breath devices that exist on the market, like Lumen, that have gained traction? Are those actually measuring ketones accurately?

Trey Suntrup:  So let’s bracket Lumen for a second. The legacy devices, breath ketone meters, most of them are really easy; a lot of these [are] pretty cheap devices that you can buy on Amazon. They’re really just repurposed alcohol sensors. So the types of devices that law enforcement uses when they pull someone over, right? There [are] some, and a lot of these sensors, there’s cross-sensitivity between alcohol and the breath ketone, which is acetone. And so those devices are basically just crude alcohol sensors that kind of disguise themselves as breath acetone meters, and so those are very inaccurate.

As far as Lumen goes, the Lumen device is actually measuring something totally different. It’s really not measuring ketones at all. It’s really measuring carbon dioxide (CO2) through the respiratory exchange ratio, or respiratory quotient. And this is just a completely different measurement than measuring breath acetone, which is a ketone. So [a] respiratory quotient can give you a sense of whether you’re primarily burning carbohydrate, or you’re starting to burn fat. But it’s actually very difficult to accurately measure that in a portable device. So normally, respiratory exchange ratios are measured using these big metabolic carts in a laboratory setting, and they have folks [lie] down for 30 minutes beforehand. And there’s a whole lot of caveats to that measurement. And it’s actually very difficult to do [with] a portable device.

I will say that the other primary difference here, because you’re measuring carbon dioxide and you’re not actually directly measuring a ketone, is that the range over which the Lumen device works is much, much smaller than the Biosense device, which is our device. So if you’re primarily burning carbohydrate, or you’re just, just, just starting to burn fat, that’s really the range over which that device works. If you are transitioning into full-blown ketosis, you’re now beyond the range of Lumen and in the range of our device. So our device covers a much bigger range of fat metabolism rate than that [one] does. And that has to do with physiology. That particular effect is not an issue of a device deficiency. It’s just that that’s how respiratory exchange ratio and carbon dioxide works. It’s just really only sensitive at [the] very, very beginning of fat burning.

Chris Kresser:  Right. So you have the issue that the more you get into the desirable physiological state of nutritional ketosis, the less accurate that measurement method is going to be.

Trey Suntrup:  Yeah, it’s essentially going to flatten out. So as you get into full ketosis, and then a little bit deeper, that device will essentially keep reading the same number. So the issue with that is that if you’ve achieved any level of fat burning at all, let’s say you’re in a low level of ketosis, and you eat something, or you try a new exercise routine, or whatever it is, and you want to see what happens to your fat metabolism rate, if you’re already, even in low levels of ketosis, that device won’t show a difference. Unless it completely kicks you out. That’s the only thing that it may show you.

Chris Kresser:  And that’s not helpful for me as a clinician when the level of ketosis that I want someone to achieve is different depending on the application. So, for example, if I’m using it for someone just to lose weight and have an impact on their blood sugar, maybe they don’t have diabetes or prediabetes, but they want to lose weight and they’re getting into the high normal ranges of blood sugar and insulin, I might use a milder level of ketosis. But if I’m treating somebody with epilepsy or working with someone with epilepsy, then I’m going to want them to be in deeper ketosis, and I’m going to want a way of measuring that.

Trey Suntrup:  Right.

Chris Kresser:  Go ahead.

Trey Suntrup:  Yeah, I was just going to say, just to underline this point, that device is really sensitive up to the beginning of the transition into ketosis. So we can talk a little bit about, if it’s okay with you, the units on our device and what they mean.

What the Testing Units Mean

Chris Kresser:  Yeah, that’d be great.

Trey Suntrup:  Yeah, so our device ranges from, the Biosense device ranges from zero to 40. The units are called ACEs, [with] zero being you’re primarily burning carbohydrate and you have no ketones, to 40, which is very, very deep ketosis. The units are set up to be approximately 10 times the blood ketone equivalent. So what that means is that, [as] I said, if people are familiar at all with measuring ketones, it’s usually the blood unit, which is millimolar, and ketosis begins around point five millimolar in the blood, which is about five ACEs for our device.

So we’ve got the zero to 40 range, and ketosis starts around five. So anything above five would be considered ketosis. So the Lumen only goes up to about three on our device. So again, three is very slightly elevated ketones, but not really making that transition to ketosis. So just to give you a sense of the two ranges.

Chris Kresser:  Yeah, it might be someone who’s transitioning. It would cap someone who’s transitioning from a Standard American Diet to a Paleo [diet], a lower-carb diet with, like, 200 grams of carbohydrate, or 150, or 100. [It] depends on the person, of course, what’s going to happen there. But it’s certainly not going to capture the therapeutic range of nutritional ketosis that I tend to use in my practice, and tend to recommend for people when they’re trying to apply this approach to address a condition that they’re dealing with.

Trey Suntrup:  Absolutely. And it’s also worth mentioning that there are other conditions for which higher levels of ketosis have really shown to be beneficial. So you mentioned epilepsy, and they have very high levels of ketosis. A lot of the anti-inflammatory effects that are associated with ketones occur above one millimolar. So in the one to 1.5 millimolar range, which is a 10 to 15 on our device. So in the clinical setting, as well, people are starting to appreciate the benefits of those sort of moderate to getting high levels of ketosis. And that’s really, our device, I should also mention, in addition to being able to sense that, is extremely sensitive at the low range, as well.

So the device was designed, we didn’t talk about this, but the device is really designed for folks who are trying to get into ketosis from a baseline of primarily burning carbohydrate. And when that’s the case, you really want to have that sensitivity at the low end so that you can tell if you’re moving in the right direction even if you’re not quite in ketosis yet. And that’s really important. We’ll talk about behavioral change tools later, but that’s very important to motivate people, right?

Because if you had a measurement that basically said no ketones and then you cut some carbohydrate out and it still said no ketones, and then there was no change even though you were making changes to your lifestyle, that can be pretty demotivating. But if instead, you’re making these changes and you’re seeing your numbers go zero, one, two, three, four, still not quite in ketosis but trending in the right direction, that’s very motivational. And I can say that from my personal experience. But I think you probably also have that experience, as well, Chris.

Chris Kresser:  Absolutely. Yeah, and that would be really helpful for health coaches that are working with folks, as well, because we talk a lot about the importance of shrinking the change, and you building on small wins, right?

Trey Suntrup:  Right, absolutely.

Chris Kresser:  Going from zero to one is a powerful motivation to get from one to two, and so on and so forth. Whereas if you can’t really track those small increments, you don’t realize that you’re making progress. And it’s going to be more likely that somebody might fall off the wagon and give up even when they’re actually making good movement in the right direction.

Trey Suntrup:  Absolutely.

Chris Kresser:  So another question this begs, of course, is what’s going on in the research setting? Given that we’ve got a lot of studies that have measured the impact of nutritional ketosis on various conditions, what is the method that has typically been used in studies? And what are some of the shortcomings of how the studies have been conducted, the measurements and the studies have been conducted?

Trey Suntrup:  Sure. So I can tell you from the studies that we’re participating in, typically what folks do if they measure ketones at all, they do it very infrequently. So they’ll do, typically, either a urinary ketone measurement or a blood measurement, but the most frequently that I’ve seen in the studies that we’re participating in is once a week.

Chris Kresser:  Wow.

Trey Suntrup:  Yeah, so they’ll bring folks in to do certain panels once a week over, let’s say, an eight-week dietary intervention, and they’ll just take a spot check blood ketone reading to see if at that moment, you’re in ketosis or not. So I think that that’ll probably be pretty obvious what the issue with that is, right?

Chris Kresser:  Absolutely.

Trey Suntrup:  Yeah, I mean, the subjects go away.

Chris Kresser:  You’re not even verifying that the primary intervention that you’re using in the trial is actually occurring.

Trey Suntrup:  Absolutely. So in the trial setting, adherence is a big deal primarily for data fidelity. But also you just want to make sure that you can confirm that the people who you’ve assigned to do a certain thing are actually doing that thing, right? Otherwise, I mean, imagine how much that can help you clean up your data set, right? Because now you’re not necessarily splitting people into, hey, this group or this cohort was assigned the ketogenic diet. And this one was not. Actually, within the cohort that was assigned the ketogenic diet, you can tell who was actually doing it or not.

Chris Kresser:  Yeah, and this is also an objective. Having accurate ketone measurements would cut to the chase because rather than relying on very unreliable assessment tools or measurement tools, like a food frequency questionnaire, to then indirectly guess whether someone is in ketosis, you determine objectively whether they are or are not.

Trey Suntrup:  Exactly, exactly. Yeah, and you bring up a good point, too, Chris, which is that a lot of, something I forgot to mention is the other primary method that they use in these clinical research studies is they just ask people, right? They say, “Did you follow your diet this week?”

Chris Kresser:  Oh, don’t even get me started. [In] one of my first Rogen appearances, I think I spent an hour talking about the problem with data collection and nutrition studies. It just makes it like a Ouija board. It’s highly problematic, and lots of renowned epidemiologists have criticized this as probably the major shortcoming of nutritional science.

But having this device that can accurately measure ketones would really, like I said, it would just completely short-circuit that whole problem. Because you’re measuring the outcome that’s the desired state, not just guessing at it from what people eat, which, of course, will vary. I mean, everybody, I think, listening to this knows, we’ve talked about ketosis before, that you can’t just assign a diet that’s the same for everybody. Even if every 10 people ate exactly the same thing, you’d see differing levels of ketones, because it’s not just dependent on the food that someone eats, it’s how they metabolize that food, right? So measuring food intake isn’t even useful in that context, in my opinion.

Trey Suntrup:  Yeah, absolutely. That brings up a really good point, which is that the personalization factor is huge here, right? So what we see even with our own users is that depending upon all the different parameters that you can imagine, like age, gender, disease state, all those different things, people’s propensity for ketone production varies wildly, right? So exactly like you said. You can give the exact same macronutrient content and you can even titrate the calories for the person’s weight, for example, and you still see big differences in how people’s ketone production proceeds.

So really what all the medical hypotheses about disease treatment state [are] that basically these benefits are related to the depth of your fat-burning state and the concentration of these ketones in your blood or in your breath. So that’s really what is driving the benefit here. And it’s connected to that and not your macronutrient content. We may need to adjust the macronutrient content of some of your subjects to achieve that desired level of fat burning or that desired level of ketosis. And you can actually do that on the fly if you’re measuring frequently enough, for example, with our device.

The Daily Variability of Ketones and Why You May Need to Test More Often

Chris Kresser:  Right. Yeah. So that’s a good segue to this other elephant in the room that a lot of people aren’t aware of, and which really is another significant challenge for both research studies and also for just at home measurement for the average person that’s trying to do a ketogenic diet, [which] is the high variability of ketones throughout the day.

So there’s been this persistent idea, you referred to it, where like, hey, if we just test ketones once a week, that should give us the data we need. Or even once a day, it turns out, according to the study that your team recently published. That’s not sufficient. So tell us a little bit about what that study found and why we now know that it’s pretty necessary to take multiple measurements throughout the day if you really want to understand the total amount of time you’re spending in ketosis.

Trey Suntrup:  Yeah, absolutely. So the study you’re talking about was published a couple of weeks ago in a journal called PeerJ. So if folks are interested, maybe we can link it somewhere.

Chris Kresser:  Absolutely, we’ll put it in the show notes.

Trey Suntrup:  Perfect. So that study was conducted about a year ago now, almost exactly a year ago, and essentially what we did is we took 20 individuals, these are metabolically healthy individuals. There was one [person with] type 2 [diabetes] in there, but it was primarily focused on metabolically healthy folks who were just interested in doing low-carb or a ketogenic diet for their own lifestyle reasons.

And so we didn’t ask them to change their diet; we just said, “Okay, you’re doing the keto diet. Just keep doing that. And while you’re doing that, we want you to measure your ketones five times a day.” So they did that both with our device, the Biosense breath acetone meter, breath ketone meter, and with the Abbott Precision Xtra blood ketone meter.

Chris Kresser:  You found people who would prick their finger five times a week?

Trey Suntrup:  Well, we made sure we put that in bold on all of the consent forms. We didn’t want that to be a surprise. But yeah, by the end, I mean, people were very happy when that part was over.

Chris Kresser:  Had some sore fingers, yeah.

Trey Suntrup:  Absolutely. So people really got into a schedule of rotating fingers and the place on their finger and that.

Chris Kresser:  Yeah.

Trey Suntrup:  Yeah, so at each of those five points during the day, and we really tried to space them out evenly throughout the day. So you’re talking about every three, four hours of your waking hours, they would take a blood and a breath measurement simultaneously. And then at the end of that, we generated around [1,200], or 1,300 data points comparing blood ketones and breath ketones, which is about two and a half times all the existing literature previously. So the reason why there hasn’t been a lot of comparisons done between the two is [that] there hasn’t been an accurate way to measure breath acetone or the breath ketone in a portable device before.

In previous clinical studies, they had used these giant lab tools where people would breathe into a bag and then run it off to this lab tool. And obviously, you can’t do that very frequently. It’s just too cumbersome. And so [those] data really didn’t get generated, and there’s not a whole lot of it. So that was the first thing is we generated a ton of data comparing the two ketones. And as you said, the first big finding from that is that ketones vary a lot throughout the day, even if you just look at a single day. And that’s the case whether you’re looking at blood or breath ketones. And what we found specifically is that they tend to vary by about 50 percent for most people throughout the course of a single day.

Chris Kresser:  Yeah, that was surprising, even to me. I’ve done multiple measurements myself and I have patients do that. But that was surprising, even to me, that level of variability.

Trey Suntrup:  Right. And the patterns are also not necessarily predictable, [from] person to person. So some folks tend to be higher in the morning, [and] some people are higher in the evening. It’s just, we don’t understand enough about the way that the physiology works. Some of the patterns you can explain, but you can’t predict them for individuals. That’s the important thing. So you don’t necessarily know what kind of person you are or what kind of patterns you have. Plus, it depends on so many different things. It depends on what you’re eating, it depends on your level of activity, it depends on your stress, it depends on how much sleep you’re getting. It depends on all these different lifestyle factors. So that was really the first thing was the variability. And that if you’re only taking one of those measurements, one of those five, you’re really missing most of the picture of what’s happening with your metabolism, even on just a single day.

So that’s really the first finding. The second is that blood ketones and our breath ketone readings are very highly correlated. So we also wanted to make sure that we had, I had mentioned those other legacy breath devices that were not very accurate. We knew that if we were going to have a good shot of a clinical use case for this device that we were going to have to come to the market with that clinical validation. And that’s the other major finding was that we had [a] really nice correlation between our breath measurements and the blood ketones.

Chris Kresser:  Yeah, I mean, this is such a game-changer for all of the reasons that we’re talking about. You go from not being able to accurately or conveniently assess ketone levels for a research study, or for somebody following a ketogenic diet at home for several different reasons. Sometimes because the technology is just not accurate if someone’s using a device that doesn’t actually measure ketones like Lumen. Or if it’s possible theoretically to get fairly accurate readings using like a blood ketone measurement device. But the compliance is going to be horribly low, because people aren’t going to take the three to five measurements a day that they need to take to really know how much time they’re spending in ketosis, either because they don’t want to prick their finger that often or because they don’t want to pay a fortune in ketone test strips, which are much more expensive than glucose test strips that you would use in a glucometer, by the way, to be able to simply just blow into a device.

And what we haven’t talked about yet is the other kind of factors that make Biosense so much more accessible and easy to use for clinicians like me is the reporting and the app that goes along with it. So it’s not just that you blow on the device and you see the reading on the device itself, but you can actually look at historical measurements and trends and all of that. And I know you’ve been working on the app a lot. So tell us a little bit about how that works.

How Biosense Works

Trey Suntrup:  Yeah, absolutely. So the first point is that the device does have a screen on it. So to just take a single measurement and see where you’re at, you can use the app or not for a single measurement, right? And that was very important to us because we wanted to make sure that you weren’t forced to have your phone in one hand and the device in the other hand. And so that you didn’t necessarily have to have a connection. You could take it with you anywhere, and just pull it out and take a measurement.

So [with] the app, you can either sync live, or you can sync the data points later. So if you want to just take your device off into the woods with you one day and not bring your phone, you can come back at the end of the day and just sync all of your measurements at once. So the syncing is done via Bluetooth; the device is Bluetooth connected to a mobile app. And as you say, there [are] all kinds of things you can see in the app.

So there are different screens that tell you the trends of your ketones over different time periods. So you can see, what did my ketones do today? What did my ketones do this week? What did they do this month and year? So any time period that is interesting to you, you can look at. And then if you want to drill down in more detail, you can. It will tell you things like what your averages are, right? So maybe, you mentioned coaching earlier, Chris, if you’ve got people that you’re coaching or folks that you’re coaching, and you can look at their week view and say, “Okay, you did great on Sunday and Monday, but what happened Tuesday?” It can just give you a summary of just that day. So really any level of granularity that’s useful for either you as a user or you as a provider, you can see in the app.

Chris Kresser:  So let’s elaborate on that just a little bit. Because we do, as you know, have a lot of coaches and practitioners who are listening to this. If I’m a practitioner or coach, and I’m working with a patient or a client, how am I able to see my patient or client’s data? Do they send it to me? How does that work?

Trey Suntrup:  Yeah, so right now, there is one-touch sharing. So that, like I said, any one of those screens, any level of granularity that you want, you can share it with your coach or your provider, either via text or email, or there’s a bunch of other options for sharing. So why does this matter? Because particularly in the age of COVID[-19] where there [are] not as many office visits, managing these lifestyle changes and certain of these chronic diseases, this is an ongoing thing. This has to happen every day. You have to be able to track the way that the different choices that you’re making are affecting your metabolism on a daily basis. You can’t, as a coach, or it makes it much more difficult as a coach to basically prescribe is probably the wrong word, but recommend certain dietary guidelines, and then send the person away. And then you see them a week or a month or six months later. It’s very, very difficult to then turn around and provide updated recommendations to that person.

So the remote monitoring of the different interventions and different recommendations and guidelines that coaches are using is such a huge deal for being able to iterate and to not only give the patient recommendations but help them understand what’s going on with themselves. Something that is really important to the founders of our company is that it’s really about empowering the patient. It’s about empowering the individual with knowledge about their own particular metabolism in such a way that eventually they can make their own decisions because they understand how these different factors affect their metabolism. So yeah, that feedback between what the coach is telling the patient to do, and then how that’s affecting their metabolism is so important to achieving outcomes, to achieving healthier, more productive people.

Chris Kresser:  Yeah. Of course, you’re preaching to the choir here.

Trey Suntrup:  Of course.

Chris Kresser:  Especially since we’ve just launched Adapt180 Health™, which is a virtual health transformation service that includes a certain number of visits with a Functional Medicine practitioner and nutritionist and a health coach, and it’s 100 percent virtual as many clinics have done in the COVID[-19] era. I mean, this was always our intention, but COVID[-19] just moved the timeline up a little bit. And lots of studies have suggested that virtual care is going to persist, and at least the amount of it that happens virtually even after the more immediate COVID[-19] threat has passed, people have already experienced it, the convenience of it, and they’re not likely to want to go back to having to go to the doctor’s office just for something simple that could be easily handled in some cases more effectively handled virtually.

Trey Suntrup:  Right.

Chris Kresser:  So the need for these kinds of at-home digital therapeutics and measurements from being able to measure your blood ketones to being able to get a simple vitamin D measurement, to measuring your body mass index or things like that, are, I think, this field is really going to take off. And Biosense is definitely playing a big role in terms of nutritional ketosis and metabolic disorders.

Trey Suntrup:  Yeah, and I should also say that something else that I forgot to mention about the app is we also have the ability to add these annotations and notes in along with your ketone readings. So what that means is that if you eat a meal and you want to log it, you can. And then that meal will show up on your graph along with your ketone measurements.

So I had mentioned the idea of feedback before, this connection between cause and effect, right? That’s really what’s going to drive adherence and drive behavior change, in the long run, is understanding how what you did had an effect or didn’t, right?

Chris Kresser:  Absolutely.

Trey Suntrup:  Or moved you toward the direction where you want to go or moved you away from it. And so you’re able to log food, you’re able to log exercise routines, or if you’re doing a fast, or if you just want to make general notes, right? You can do all of that in the Biosense app and you can see that information alongside your ketone data. So that’s very, very powerful. And that can also be shared with a coach or clinician.

Chris Kresser:  Yeah, that’s huge for all practitioners, nutritionists, [and] health coaches. Before Biosense, and even in some cases when we still are wanting to measure blood sugar rather than ketones, we have patients do three days of testing with a glucometer and we have them test right before a meal, 45 minutes after a meal, an hour after that, and an hour after that. And then we purposely have them eat a higher-carbohydrate meal on the third day. And what they get a chance to see with their own eyes if someone has metabolic issues and carbohydrate intolerance, is their blood sugar will skyrocket in that 45-minute and hour and 45-minute value.

And that immediate direct feedback is worth reading 10 books and 100 blog articles about that, where people actually get to see the results. And then even better, and this is true for the Biosense device, too, people can use the device to get real-time, objective feedback on what their carbohydrate tolerance is, and how much carbohydrate they can eat while staying within their goal range. Whether that’s full-on ketosis or just mild ketosis, they actually then can get feedback on what they’re able to eat and stay in that range. So that’s just really something that has not been that easy before. My patients are pretty hardcore. So they were willing to do that with the glucometer. But certainly, we know that, in the general population, that’s going to be a lot less. The compliance rates are going to be a lot lower with that.

Trey Suntrup:  Right. And those types of patterns are just impossible to predict, without actually measuring. There’s just no way you can say what effect something is going to have on you in particular, because as you said, [if] two different people do the exact same thing, the responses look totally different.

Chris Kresser:  Yeah, and we didn’t really get into this. But there are other non-dietary factors that affect ketone production, like strenuous exercise, for example. So that makes it even harder to just guesstimate because there [are] multiple factors that are all interacting in sometimes unpredictable ways. So even if you eat exactly the same thing on two consecutive days, you might end up with differing levels of ketone production, depending on those other contributing factors.

Trey Suntrup:  Yeah, it’s interesting. We actually had a user write to us once who was asking about why their ketone, they described what they had been doing and their ketones had dropped from one week to the next. And they couldn’t quite figure out why. And after a couple [of] rounds of questions, what we figured out is that the person actually had a huge presentation coming up and they were stressed. And stress and elevated …

Chris Kresser:  Cortisol, blood sugar goes up.

Trey Suntrup:  Yeah, there you go. There you go. And it’s something that that person had never even considered before. But it’s just another one of those factors.

Chris Kresser:  Where it’s similarly, a poor night of sleep, that can affect cortisol levels and blood sugar. We’ve seen that in lots of studies. So yeah, lots of factors, and probably some that we don’t even fully understand yet. So that’s another value of having [these] more objective data.

Trey Suntrup:  Yeah, you’re absolutely right.

Chris Kresser:  Trey, thanks so much for coming on the show. And folks who are out there who are interested in ketosis and want to [a] get more accurate measurement, how do they get their hands on one of these devices? And before you mention that, I just, as always, I’m very transparent about my relationships, and I am on the advisory board of Readout Health, which is the parent company for Biosense. And as I have told [my] listeners many times, I only invest in or advise companies that I believe in, and whose products I use myself or in the clinic. But I always want to be very clear about what the existing relationships are.

So take that as you will, and Trey, let people know where they can find a Biosense device.

Trey Suntrup:  Sure. So the device can be found at MyBiosense.com. So if you just go to that website, there’ll be [an “ORDER ONLINE”] button that you can click. And listeners of the podcast can enter the code ADAPT, a-d-a-p-t, at checkout for a $30 discount on the device.

Chris Kresser:  Oh, great. Thanks for that. [I] appreciate it. And I know all the listeners will, as well. There [are] so many folks out there who are doing some type of restricted carbohydrate dieting, whether it’s just lower-carb or full-on ketosis or something in between. And this device is a real game-changer for anyone who’s doing that.

And also for the practitioners and the coaches and nutritionists and even researchers who listen to the show, make sure to check this out and consider incorporating it into your protocols and the way that you work with clients or patients who are following a ketogenic or a low-carb diet. It’s made a huge difference for us in our practice. And being able to access the data and talk about [them] with your clients and patients is definitely a game-changer. Trey, thanks so much for coming on the show.

Trey Suntrup:  Thanks so much, Chris, for having me.

Chris Kresser:  Okay, everybody, thanks for listening. Please do continue to send in your questions to ChrisKresser.com/podcastquestion. We’re not doing Q&A format these days, but they definitely inform the topics that I choose and the guests that I invite on the show. So thanks again, everybody, and we’ll talk to you next time.

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