The Antisocial Doctors Podcast
Join Dr. Rebecca Berens & Dr. Sonia Singh as they unpack viral health trends with curiosity, nuance, and compassion. No snark, no shame —just thoughtful conversations about what’s true, what’s hype, why we're drawn to it and how to find calm and clarity in the chaos of social media and online health advice.
The Antisocial Doctors Podcast
Episode 21: Is Continuous Glucose Monitoring Actually Helpful?
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In this episode, we dig into the hype around continuous glucose monitors (CGMs) and why they’ve suddenly become a wellness must-have. We share real patient stories that span the spectrum—from genuinely helpful use to unintended harm—and use them to explore what’s driving the trend, what people hope these devices will reveal, and where things can get confusing or stressful. We also unpack what “more data” really means in real life, why interpretation matters, and how personalization can be both empowering and risky.
00:00 Podcast Mission
01:18 CGM Patient Stories
03:38 Social Media Claims
06:24 Why CGMs Are Trending
09:59 Real Benefits And Limits
12:43 How CGMs Actually Work
16:51 Who Benefits Most
23:06 Prediabetes And Healthy Users
27:29 Normal Range Anxiety
33:19 CGMs In Eating Disorders
37:17 Silent Hypoglycemia Risk
38:19 CGM Study Extremes BMI
40:37 Biofeedback Versus Harm
43:06 CGM Harms And Overuse
44:18 Whipples Triad Proof
45:34 Normal Spikes Aren’t Disease
49:18 Psychological Burden Study
54:44 Carb Reintroduction Crashes
01:00:19 Practical CGM Use Guidance
01:07:21 Work With A Dietitian
01:08:43 Final Disclaimer
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You're listening to The Antisocial Doctors Podcast, hosted by me, Sonia Singh, a board-certified internal medicine physician with a master's in nutrition and a special interest in health anxiety.
Rebecca Berens MDAnd me, Rebecca Behrens, a board-certified family medicine physician with a special interest in disordered eating.
Sonia Singh MDWe're also millennial women, anxious moms, and curious humans navigating social media. We've seen firsthand how these platforms can be powerful tools for education and connection, but can also make us unwell.
Rebecca Berens MDThis podcast is meant to be the antidote to your doom scrolling, a solve for the anxiety, stress, guilt, shame, and confusion that comes from social media's messaging around health. In each episode, we discuss a health-related topic trending on social media with curiosity, nuance, evidence, humility, and compassion.
Sonia Singh MDThis is not your average debunking podcast. We wanna explore not just what is trending on social media, but why. Why are so many people drawn to this? What is the nugget of truth here? What are the facts? What can we learn from this as patients and doctors? No shame, no blame, no snark.
Rebecca Berens MDWe're so glad you're here.
Sonia Singh MDHi, Rebecca.
Rebecca Berens MDHi, Sonia.
Sonia Singh MDSo I feel like all of our episodes in this batch are piggybacking off each other which is kinda nice, 'cause they're building. But our last episode that we recorded was about fitness trackers, and now we're doing an entire episode around a more specific subset of that. So do you wanna share the patient story and the topic for today?
Rebecca Berens MDYeah, so I have a few patient stories again. And again, with very different use cases for this situation. So the first one is a patient of mine who's uninsured and has been on multiple medications for managing their diabetes that unfortunately was diagnosed very late because of their lack of access to healthcare. But we made a lot of progress with with meds and were able to get it down to an A1C of eight, and we just could not get it past there despite medications. And they got a commercial over-the-counter CGM themselves online and started using it, and they were able to pretty significantly improve their A1C and get it finally into the low sevens which was wonderful. Then I have another patient who has a recent diagnosis of pre-diabetes and metabolic-associated fatty liver disease, who I referred to a dietician, and the dietician remeng- r- recommended that they start working with a CGM while they were making their, Dietary changes in context with a dietician. And they found it very helpful to understand how food impacts their blood sugar, and they were able to get their A1C from a low sixes down to normal after about four months, which was great. But then I have another patient who was in eating disorder treatment and had a continuous glucose monitor placed for that because they were having hypoglycemic episodes related to their eating disorder, and kept getting alarms after eating that their blood sugar was dropping and noticed that their blood sugar was better when they didn't eat, so then they stopped eating as recommended by the treatment team. So all continuous glucose monitors with varying impacts on people's health conditions and we'll talk about how that... how, why that may be as we go through this episode.
Sonia Singh MDYeah, I'm glad you shared multiple examples in this case, 'cause I think, when you only share one, it starts framing it a certain way, and you d- you covered the full spectrum of- Yeah Highly useful scenario to possibly harmful scenario. Yeah, I'm glad that, I'm glad that we're describing the full spectrum of outcomes. So what do you think are the claims made around CGMs or continuous glucose monitors?
Rebecca Berens MDYeah. So I've seen several, but a lot of it plays into the same things that we've been talking about in general. More data is better. If you have the most data, you can optimize your health. You can learn which diet is right for your body, which foods you react well to and you don't react well to, what you should be eating, what you shouldn't be eating based on how your glucose is responding. I think there's also a lot of telehealth companies or not even telehealth, but telecoach companies- where they're saying "We can help you lose weight, and use this tracker, and it'll help help you lose weight. And we'll help you, interpret the data." Then I think there's also this idea of hidden illness. There could be something wrong with you, and no one's diagnosed it yet, and this is a way that you can get the data to diagnose it before someone else would... before your doctor will know. Again, being, proactive, being more proactive than the healthcare system. The healthcare system is waiting until you're really sick, and this is a way you can proactively address your own health and i- identify a problem before it can be diagnosed a- another way. And then there's also just the idea of glucose is bad, and sugar is bad, and sugar spikes are bad, and they're gonna make you sick, and this is how you can make sure you avoid those. So those are a lot of the claims that I've seen. What about you? What have you seen on social media for these?
Sonia Singh MDYeah, I think, Blood sugar is one of those kind of boogeymen, like hormones and some other things in the wellness world where people feel generally unwell, and they start to think "Maybe it's my blood sugar. Maybe my blood sugar is too high. Maybe it's too low. Maybe I'm having spikes. Maybe I'm having crashes." And it's also one of these things where I think most people have experienced at some times feeling like, "Oh, I'm really hungry. I need to eat," and that badness of that feeling, and then thinking "Oh," "maybe some mild version of that is happening to me at other times, and I'm just not aware of it," and the doctor's not catching it because they're only che- checking an occasional blood test. Or the A1C's just inadequate, and it's not catching that, these... Even though my average blood sugar might be normal, what if I'm having these huge spikes and dips and I'm not knowing about it, so I think that's part of it. Yeah, the, those are the claims that I've heard around them. It's this way to get... get a better understanding of how different foods are making you feel or how your body is reacting to different foods or activities.
Rebecca Berens MDYeah. Yeah, with the idea then that you will increase the ones that make you feel good and make your glucose look good, quote, unquote, and cut out the ones that make you feel bad or make your glucose spike.
Sonia Singh MDYes. Yeah. And it plays into this idea that everyone is really different. And maybe a cup of brown rice is okay for somebody else, but it's not okay for you because- it spikes your blood sugar, and you might not realize. Yeah, I think that all of those are rolled into,, what the claims are around some of these devices.
Rebecca Berens MDYeah.
Sonia Singh MDSo why do you think these are becoming so popular at this time? Because the technology of this is not that new. So why do you think they have risen to fame over the last couple of years?
Rebecca Berens MDYeah. So similarly, like we've talked about before optimization culture has become mainstream with, I think since COVID, since, more social media health content in general. And there's more of a demand for more data, and so there are companies that have these devices that can supply that data to you. And so then they market said devices using social media, using influencers. There's telehealth companies that can capitalize on that trend and and, build into programs. And again, this is something that if a telehealth company is delivering to you not just, "We're gonna talk with you," but, "We're gonna give you data"- like I see a lot of those things where it's like, this is part of our program. It's very comprehensive. Look how much data you get." I think it just it adds to the marketing that plays into that optimization desire. And then like we talked about too, I think the idea of personalized care versus generic healthcare. You kinda touched on this. Like- Yeah what works for me is different than other people, which, fair. It's true. Yeah. But also we'll get into the harms of that as well. But yeah, I think it's an idea of getting something that's more personalized and not just generic and and basic and not the full picture like you get- from normal healthcare, right? And then I think again, the, a lot of this did balloon in the face of COVID, and I think that was partially increased perception of mor- our mortality, fear of health problems. It, it was- commonly discussed that metabolic conditions were a risk factor for more severe COVID cases. And so that obviously is gonna make people concerned. Am I someone that might be at increased risk? Is this something that's a risk factor for me? A lot of people have seen family members go through, horrible complications related to uncontrolled diabetes, for example. The number of patients I have that come in and they're concerned about diabetes specifically because they saw a family member who had an amputation. I think that's a really common fear that people have when they've observed that happening to a loved one, and they're like, "I don't want that to be me." How can I prevent that? How can I... and again, it's like you wanna be proactive. You wanna be doing everything you can t- for your health.
Sonia Singh MDYeah. I also think there's this whole- movement happening right now around metabolic health that weirdly has become politicized in some way. Yes. So I think there's just a lot more interest in and attention in metabolic health, which is... if you had told me that would be a hot topic or people would be into that 20 years ago, I would've just laughed in your face because it just seems it, it seems like a very unsexy, uninteresting thing for, people to be so b- buzzed about. But they are, and it's become, I'm, I'm glad, but people are aware that this is a thing that is happening on a societal level. But I think when you go to the sort of extremes or what I would've considered the fringes of that movement, you'll find people that basically have this view that sugar is the greatest evil that has like ever existed. And so I think, a lot of people come back to the idea that like, okay, if you can just track and monitor your blood sugar, really diligently, all of that other stuff you know- Yeah will not happen.
Rebecca Berens MDIt's the root of all problems. Like everything-
Sonia Singh MDIt's the root of all
Rebecca Berens MDproblems.
Sonia Singh MDYeah.
Rebecca Berens MDYeah. Everything that's wrong with you is because of the sugar, and it's well-
Sonia Singh MDYeah, there was a tweet around this. I can't remember what the tweet was, but yeah. It was something about like sugar was like the most harmful substance or something like that- Yeah that's ever been created. So I, I think along with that demonization of sugar, there's this idea that okay, if you can just control and fine-tune it really perfectly, that would be the ideal. That's the, one of the, holy grails of somebody who's trying to be healthy.
Rebecca Berens MDYeah. Yeah, absolutely.
Sonia Singh MDSo what do you think is the nugget of truth around the benefits with CGMs or around some of those claims?
Rebecca Berens MDYeah. So the first thing I'll say is it is true that having uncontrolled high blood sugar over many years has serious complications. That's why we care about diabetes, right? We treat diabetes because it, there are these long-term complications that can happen with exposure to very high blood sugars, damage to, blood vessels, nerves, Can increase in infections, immune system dysfunction, all of these things related to uncontrolled high blood sugars over time. So it is important, especially if, if you have diabetes, to control your blood sugar. That is true, right? But normal glucose fluctuations, like the spikes that people are worrying about on these CGMs, that's not the same thing. So we'll get more into the details of that. Yeah. But I think, I don't wanna gloss over the fact that yes, it is important to control your blood sugar when you have diabetes. That is absolutely true. The other nugget of truth is that there actually is good data that these devices can be beneficial for some patients, particularly patients who have type 1 or type 2 diabetes, and even sometimes with prediabetes- to help them be better able to manage their blood sugar and support their behavioral modifications, support adjustment of medications, and give more, more insight compared to in the past when we had a lot less data that we were going off of to make recommendations and decisions about changes. And it's real time for patients, too. Yeah. Right? You're, they are able to to learn and adjust their behaviors based on feedback on a more real-time scale versus every three to six months finding out like, "Oh, turns out that I've actually not been doing very well, and I didn't know."
Sonia Singh MDYeah
Rebecca Berens MDyeah, so you know, I think there's truth to that. But again, just because it's beneficial for some people, maybe not for others, and we'll get into that.
Sonia Singh MDAnd just, so just to clarify for maybe some of our non-medical listeners, when we're talking about CGMs, we're talking about continuous glu- glucose monitoring, which is different than checking a finger stick blood sugar- Yes which many people have been doing for many years. The technology for CGMs is a little bit newer. At this point it's not particularly new, it had been only available by prescription for patients with insulin-dependent diabetes. That's the context that I learned it in. And then it trickled down to other patients with diabetes, and then it trickled down to patients with prediabetes. And truthfully, I feel like I was a really big fan of CGMs until they became available as consumer products.
Rebecca Berens MDYeah.
Sonia Singh MDSo you know I, d- you know, with, for my patients with those conditions, I was always encouraging if they wanted them. And now, I, I I guess it's partially just the population that I take care of now, but I'm much more likely to get questions about it or get sent data from somebody who does not have any of those conditions that is asking me- about, this, the, what their results mean. So okay. So let's talk a little bit about what the actual facts are and what the science tells us about CGMs and how they work, what benefits they have. Give us a little more information on that.
Rebecca Berens MDYeah. So I'll start with just explaining like what is- a CGM and how is it different than a finger stick blood glucose? Oh, okay. 'Cause the last year alluded to, they are different, right? Yes. Yeah. And so as you said, a continu- a CGM is this continuous glucose monitor, and so it's measuring your glucose pretty much continuously. The prescription options are measuring every, between one to five minutes, and reporting on that every one to five minutes. The over-the-counter options are also measuring about every five minutes, but they only send reports every 15 minutes to the- the apps associated with them. So that's the difference between those two. But the way that they are measuring glucose is different than the way that a finger stick or a venous blood sample measures glucose. They are actually this is a little small circular device. Everyone at this point has probably seen w- someone walking around with these on their upper arm, 'cause they're everywhere. And it's usually placed on the upper arm, and has a teeny little electrode thing, needle, tiny little thing that goes on, and it's actually measuring interstitial fluid glucose. It is not measuring blood glucose. Whereas when you get a finger stick blood sugar or a venous sample of your blood, that is measuring your, directly the blood sugar. And so the interstitial fluid glucose is the fluid around in between your skin and tissues is what it's measuring. It's not measuring the blood directly. So that's the first sort of important thing to to clarify the difference between the two, because those are not the same thing. Now it is going to approximate the blood sugar, but it's going to lag because the interstitial fluid and the blood glucose levels will equilibrate and approximate each other, right? But they're not the same thing, and there is gonna be a lag. So when your blood sugar is changing, there's gonna be a lag in that showing up in the, Interstitial fluid interstitial fluid. Okay. And the benefit of the CGM is it gives you lots of data over time, and so you can see trends, and that's really what the CGMs are most helpful for, is understanding trends and how your blood sugar is going up and going down, again, with a slight lag a slight delay. Whereas a finger stick or a venous sample is giving you more of an absolute value what is your actual, the actual value of your blood sugar in a very accurate way. And during rapid changes to your blood sugar if your blood sugar is rapidly dropping or rapidly increasing the number that you see on the CGM is not necessarily going to match the number that you see on a finger stick blood sugar. They can be quite different, 'cause again, takes time for it to re-equilibrate, recalibrate. That's the difference between those two things. I think it's also important to note that there are several factors that can influence the readings on the CGM that are actually unrelated to what your blood sugar is. So for example if the device is compressed, and this happens a lot when people are sleeping, if they roll over and press on the device that can restrict blood flow to the area, and it can cause a false low reading. If you're, exercising or sweaty or get dehydrated 'cause you're sick, that's gonna affect your fluid levels- and that's gonna affect the reading. There's certain medications that can affect it. On some older models, maybe not so much the new ones, but Tylenol was one that that did have an impact on on the measured levels with the CGM. Vitamin C at high doses also can, and hydroxyurea, which is taken by some sickle cell patients. And then it also matters how you place it, right? If you place it incorrectly and the little electrode thing is not where it's supposed to be in the skin- if it's in the muscle or, or it's in skin that's too thin or something like that, and it's not able to get a good reading, that's also gonna impact it. That kind of is a brief overview of how they work. Anything you can think of that I might have missed, Sonia, or that you think- questions people might have if they're non-medical?
Sonia Singh MDNo, I didn't know the thing about vitamin C potentially causing false high readings, which is interesting, because when you're taking any supplemental vitamin C, it tends to be high doses. It's always 1,000% of your daily value. I can imagine somebody drinking a little Emergen-C or one of those greens powders or something and being like, "Oh my God, it really spikes my sugar." So yeah, those are all good little caveats to know about. Yeah. So what is the evidence on who can actually benefit from CGMs?
Rebecca Berens MDOkay. So yeah, to start with as we talked about, these were designed for people with diabetes, and initially, in particular, people with insulin-dependent and initially, specifically Type 1 diabetes. For example, people who've been on insulin pumps for- Type 1 diabetes, that's been around for a while. Yeah. Continuous glucose monitoring for them is not a new phenomena. Yeah but it started to be applied to people without pumps, so just with Type 1 diabetes who are insulin dependent without pumps. And I wanna just share a few studies talking about the use of these medications in patients with diabetes, because there, there is good evidence for benefit with these patients. So the first one I'll share is called Effects of Continuous Glucose Monitoring on Metrics of Glycemic Control in Diabetes: A Systematic Review with Meta-Analysis of Randomised Controlled Trials. So this meta-analysis and systemic review the randomized controlled trials that they assessed were looking at changes in A1C time spent in the target blood sugar range, so TIR, time spent below the target range, so TBR, that's if the blood sugar is too low, and time above target range, meaning blood sugar is too high. And it was i- showing the impact of using a CGM on those metrics for these patients. And these were all patients who had either type 1 or type 2 diabetes who were on insulin. So very important to note, these all were patients on insulin. Okay? And this was either continuous insulin or multiple shots a day, so not even just one basal dose of insulin for a type 2 diabetic. This is someone- Yeah who's taking an intensive insulin regimen. And they did see with this a modest reduction in the A1C, which is by about le- minus .17%, so not huge, but a little bit. Increased time in range, and lower time outside of the range, meaning too high, too low. And the increase of time in range was significant and robust independently of diabetes type, so it didn't matter if they were type 1 or type 2, and method of insulin delivery, so whether it was a pump or injections. So good evidence there that there's some improvement in keeping the blood sugar in the target range when you're on insulin if you're using a CGM.
Sonia Singh MDYeah, so fewer extremes, basically- yeah is what they were able
Rebecca Berens MDto achieve. And the extremes are what we care about, right? Because- Yeah the hypoglycemic events, particularly if you're on in, on insulin, and you have a severe hypoglycemic event that can kill you. Medical
Sonia Singh MDemergency,
Rebecca Berens MDyeah. Hypoglycemia is really dangerous. Yeah. And that's something that's important to be able to quickly identify and correct. And then again, if you're persistently above your range, that's keeping your blood sugar in a high range over a long period of time, that's where we see those complications of diabetes increase. And so that keeping them in that target range is not only reducing your risk in the short term, it's also reducing your risk in the long term for complications- of diabetes. There was also a study similarly, that was done in more of a General living population, which was done at the VA. And they initiated CGMs for patients with type 1 and type 2 diabetes within the VA system. And the interesting thing to note about this is that so type 1 diabetes is an exclusion criteria for military service, so these were all patients with adult onset type 1 type- diabetes. Okay. So just important note there on the population. And they were looking to compare glucose control as well as hypoglycemia or hyperglycemia related admissions to the emergency room or hospital, as well as all cause hospitalization. So this is more than just are we keeping the glucose controlled, but is it also impacting the patient's, short term- Clinical outcomes, yeah with health, right? Are they getting hospitalized m- less? And these also, again, were all on insulin, so I have to be very clear with that. These are type, people with type 1 and type 2 diabetes on insulin, not people- Yep who are not on insulin. Okay.
Sonia Singh MDYep.
Rebecca Berens MDSo they did see with this that significantly greater declines in A1C in patients who were using CGMs with both type 1 and type 2 diabetes at 12 months, and a greater percentage of patients who were able to get their A1C less than eight and less than nine. So these are patients who are very uncontrolled with their A1Cs in the past and now have been able to get them lowered with the use of the CGM. And in type 1 diabetics, CGM was associated with a significantly reduced risk of hypoglycemia and all-cause hospitalization. In patients with type 2 diabetes, there was a reduction in risk of hyperglycemia in CGM r- users, so they're reducing the high blood sugar events- as well as all-cause hospi- hospitalization for these patients.
Sonia Singh MDOkay. Pretty good data- Yeah supporting their use in those populations.
Rebecca Berens MDYeah. So if you are a diabetic of either type and you use insulin, solid evidence this is good for you, right?
Sonia Singh MDYep.
Rebecca Berens MDOkay. So next we have the much larger population, which is people who have type 2 diabetes and are not on insulin. Yeah. 'Cause that's a very large number of people with diabetes. And I will say importantly, a lot of times insurance companies will not approve- Yeah the use of CGMs in people who are not using insulin. And so that's a, that's just an important caveat because I think that impacts access for a lot of people to these devices. So this study that I'm gonna cite was continuous glucose monitoring in non-insulin treated type 2 diabetes, a critical review of reported trials with an updated systematic review and meta-analysis of random c- randomized control trials. And, They looked at randomized controlled trials that enrolled mixed populations with Type 2. So some were on insulin, some were not. That's what they mean by mixed populations but were including non-insulin diabetics in these. And then they specifically did a systematic review of the randomized controlled trials that were only non-insulin treated compared to just usual care whether they were using a CGM or not. In these s- in this study or in this meta-analysis and review there was a consistent benefit demonstrated of CGM on both glycemic and non-glycemic outcomes. So meaning improved A1C, improved time and range and reduced healthcare resource utilization for this, these population.
Sonia Singh MDOkay. So looks like there's decent data too for using in patients with diabetes who are not insulin dependent.
Rebecca Berens MDYeah. Great. So solid. No concerns there. Next up, pre-diabetes/ Okay metabolic syndrome. So these are people who do not have diabetes and definitely would not be able to get one of these approved through insurance. But have evidence of impaired glucose tolerance, meaning they have higher than normal fasting glucose, they have a higher than normal but still below the diabetes threshold A1C or average glucose over the last three months or they're showing evidence of insulin resistance or have other metabolic health complications associated with that, like a metabolic associated fatty liver disease, for example. And this was again, a systematic review and meta-analysis continuous glucose monitoring in non-diabetic populations, a systematic review of observational and interventional studies with meta-analysis. And most of the studies that they were looking at were targeting health promotion through lifestyle interventions for improving blood sugar, weight management, dietary behavior modification, and enh-enhanced adherence to recommend-- like medical treatment recommendations when it comes to lifestyle. And they did demonstrate that the CGM significantly improved their blood glucose, but there was no significant difference on body mass index. That was- So
Sonia Singh MDdid not help with weight loss, but- Did
Rebecca Berens MDnot help with weight
Sonia Singh MDloss it did help with lowering the
Rebecca Berens MDaverage Yes. Did help with with blood sugars. But the important thing that I thought was really interesting, was CGM was associated with higher behavioral adherence and specific dietary modifications. Notably, CGM improved glycemic control in individuals with prediabetes, whereas no appreciable glycemic benefit was observed in healthy, normal glycemic populations. So because some of the studies that they were looking at were just general health promotion- there was maybe some people involved that were not actually,
Sonia Singh MDPre-diabetic
Rebecca Berens MDpre-diabetic. And so there was im- improved control for people with prediabetes, but not really an appreciable change if you don't have prediabetes. Okay.
Sonia Singh MDOkay. And is this the best we have in terms of benefits of CGMs for a healthy population, a normal glycemic population?
Rebecca Berens MDThere's not a lot of other study on this population- Okay as it relates to any benefits, that I could find, anyway. And I think when we get into the harms, there's been some study on that in healthy populations who do not have prediabetes. And the key thing also is to understand that we don't have normalized ranges- for glucose fluctuations in healthy individuals, right? It's even hard to say what is a better blood sugar if you're already- Yes normal. How do we make- it better? So it's even hard to measure, yeah. What are we controlling it against? How do we say it's better? We don't know what it's, what we're trying to get it to if it's already normal.
Sonia Singh MDYes. Okay, one thing I wanna point out before you move on is I think what a lot of people's perception of how they feel when their blood sugar is high or low is a little bit not in line with what is the medical reality. And so I think a lot of people turn to CGMs when they're thinking "Why am I so fatigued?" "Why do I feel foggy? Like, why am I dragging? Why do I have this slump in the afternoon?" And of note, there is no study that's looking at CGM effect on fatigue or energy level. There's no study showing-
Rebecca Berens MDYeah
Sonia Singh MDThe things that I think people believe it is likely to help with are things that we have literally no data on. Because honestly, there isn't even a really great physiologic pathway there that makes a lot of sense. Anyway, okay. So there's not much data for CGMs in healthy populations for- I guess you, y- if you were to study in that population, the question would be like what is the outcome you're looking for if there already-
Rebecca Berens MDI'm like, what would you, what
Sonia Singh MDwould you measure? If they already have normal blood sugar. What are you targeting? Yeah. I'm
Rebecca Berens MDlike, how do we measure that it's better when it's already normal?
Sonia Singh MDThat it's working.
Rebecca Berens MDYeah. Yeah. And
Sonia Singh MDthat would... That... that's probably why those don't exist, 'cause, like the question is what are you aiming for? Yeah. What's the goal here?
Rebecca Berens MDYeah. I wouldn't- I wouldn't know what to say. But it is notable that there was no change in BMI because I do think that is often a reason that it is touted. And even in- Yeah this p- in this population who... These are people who do have maybe pre-diabetes or metabolic issues it was not appreciably changing their BMI to use the CGM. Now, does that mean on an individual level if a person uses a CGM and changes their behaviors significantly because of the feedback they're getting from the CGM that they won't lose weight? No, they might.
Sonia Singh MDIt's
Rebecca Berens MDpossible. But it's not something that you can say "This is going to make you lose weight." We don't have data to support that.
Sonia Singh MDOkay. I have- So- I have a theoretical question for you. Within the normal range of blood sugar, what if somebody says my average blood sugar is 95, but wouldn't it be better if it was 90?" So tell me what your thoughts are on that.
Rebecca Berens MDI don't know how we could possibly know. I don't know how we could know that.
Sonia Singh MDOkay. So your answer is we don't really know if that's any-
Rebecca Berens MDYeah. I don't think that we know if that's better. I think we do know if you are, say, at the high end of normal for your baseline-
Sonia Singh MDYeah
Rebecca Berens MDare you maybe going to have a more pronounced response to certain foods when you eat them- and therefore have a higher spike? Maybe. But what matters to me more so is is it coming back down appropriately?
Sonia Singh MDYes.
Rebecca Berens MDOr are you struggling to lower it after it was high? And that, I think, is a different, that's a different measurement than av- what is your baseline?
Sonia Singh MDYeah. I just think about that in terms of... I get this question a lot. I go over lab results with patients in really great and gory detail because I have the privilege of being able to do that in my practice model. But when you do that, you find that people often have these questions about my potassium was 3.6, and now it's 3.9," and, but- or, "Now it's, four point- 4.4 and doesn't that, isn't that kind of concerning? They see something that looks close to the range that is a high or low, and they think doesn't that mean something? And with something like potassium, I feel really confident saying, "Look, it's gonna fluctuate day-to-day." Yeah. That little blip between- Hour
Rebecca Berens MDto hour.
Sonia Singh MDYes. All these little variations within the normal range are so meaningless to me. Do not worry about that. That is not a thing. I think it's slightly harder to make that argument about the blood sugar, and that's where I think a lot of patients get hung up. I even have patients get hung up on the A1C where they're like, but it's 5.5, and 5.6 is the cutoff for prediabetes don't you think I should jump on this now and get the CGM and get this thing down?" And I'm asking you 'cause I genuinely don't know how strong this data is. What I usually tell them is "Look even prediabetes is, for us it's a red flag, it is a sign of something. But many of those people will never progress to diabetes." You still have plenty of opportunity to work on this. And, each of those .1 percentages is probably farther apart than you think it is." I have a whole spiel on it. But I do wonder can I point to data that's "Look, it's okay for you to be 85 versus 90 versus 95 versus 99 o- of an average blood sugar"? And I don't know the answer.
Rebecca Berens MDYeah. I think one thing that I would say is they came up with the cutoffs for a reason. Even for people with diabetes, our goal is not to get their A1C to 5.6. Yeah. Our goal is to get their A1C less than 7.0. And that has to do with with a break point of we see an increased rate of complications- Yeah above that. And targeting too low below that has risks, too- of overmedication, right? And so when you have someone who's not even high and we try to lower it further, I think you are in- incurring greater risk of overmanagement without- Yeah clear evidence of benefit. Yeah. Okay I
Sonia Singh MDthink- I think that's a great answer. Yeah. Yeah. Yeah. No I think the argument that's okay, look, maybe your average blood sugar is 95. Maybe you would like to see it be 90, 'cause that feels safer and better to you. But what we know is having this average blood sugar consistently below 100 is completely within normal physiology. So whatever efforts and changes you would make to try to lower that- may not have any tangible benefit. I guess that's a reasonable answer- Yeah to say m- maybe, but we can't really quantify that benefit or tell you really concretely what that would be, and there would likely be some potential harms in Yes whatever you would be, whatever you would be doing, restricting, changing in order to do that.
Rebecca Berens MDYeah. And I think that's the key is like it's always, okay, what's the potential benefit? What's the potential harm? If we don't have any potential benefit that we can really point to, then you only have harm. So then-
Sonia Singh MDBut I think- a lot of people listening to this, and again, I'm playing devil's advocate. I'm pushing here- because this is what I hear.
Rebecca Berens MDYeah. This
Sonia Singh MDis what I hear from people. Yeah, sure. I think their answer to that would be like sugar... Isn't sugar bad?" Sugar- is bad, and so wouldn't having less sugar, reducing the sugar in my diet, wouldn't that be good? Even if, yes, I'm just moving from five points in the normal range to five points lower than the normal range, wouldn't that still be a positive thing for my health?
Rebecca Berens MDI think that depends very much on what is the current sugar content of your diet because there is a point at which it's too low. Yeah. Right? We need to have carbs. You have to have carbs. I think, we certainly know that if you are eating a lot of highly processed foods with refined sugars that do not have a lot of fiber you're going to get more prominent spikes and dips in your blood sugar, which, we can get into all of that in a little bit here. But, there... Yes, if You're consistently getting a lot of sugar to the exclusion of other important nutrients I could see how, yes, it would s- we could say "Yes, there may be a benefit for you," but I would still say it and add those things, not take away- Yes. The sugar. Like I wouldn't, I would never express it that way because I think it's unhelpful. And also, the sugar is not bad, especially if your body is able to use it properly.
Sonia Singh MDYeah.
Rebecca Berens MDThat's not the problem. The problem is if your body is not able to use it properly and it's staying higher than it should for a longer period after you eat, that is where the problem comes in. I don't think that we can prove that there's any problem to having a spike in your blood sugar that comes right back down again and normalizes in an appropriate span of time. I, I've, I don't know, I've never seen anything that's proven any harm to that.
Sonia Singh MDOkay. I'm assuming we're gonna get into the, the- the, that in more detail. Yeah. But okay. I took you on a tangent. Yeah. So let's get back to what is the data on CGM use in eating disorders? I didn't even know... I am not familiar with this data at all, so I'm really curious what you-
Rebecca Berens MDYeah. So there's not a ton of data, but I will say this is an emerging area of like very active discussion and, And trials, I will say. So there has been some-- for anorexia, for example, anorexia has a very high mortality rate, and some of that is related to suicide, but some of that is related to medical complications one of which is hypoglycemia. Okay? So low blood sugars especially overnight can result in death for patients with anorexia. So there was this idea hey, if we can monitor blood sugar for patients who have anorexia or have another eating disorder, maybe it can help us to avoid some of that complication. I think there's also the idea of maybe we can get more accurate data about, how often the patient is eating because maybe their report is not always accurate, and we can get more information from trends on a CGM. So there's not a hun-- a whole ton of data on it actually but it is something that I think is is being actively discussed and looked at, and probably there will be more data in the near future 'cause it's currently being studied. But I think also there is the idea of helping to prove to a patient that there's a problem. Yeah. If a patient doesn't believe you that they're really that sick which is a common feature of eating disorders is like, "Everything's fine," "I feel fine. There's nothing wrong." And often labs are normal on these patients- Yeah too, and so especially if the patient has a quote-unquote "normal BMI," because only about six percent of people with eating disorders are at a below normal BMI it's really hard sometimes to convince them that what's happening is actually harmful. And so- sometimes having, again, some data to be like, "Hey, this is what we're seeing that, that tells us that you're having a problem," there's some idea of using it for that reason as well. But anyway the studies that I did find there was one which is continuous glucose monitoring assessment in patients suffering from anorexia reveals chronic prolonged mild hypoglycemia throughout the day. And this was a pretty small study. It was done in Europe and it's twenty-eight women who have anorexia and were at a very low BMI, below seventeen point five, between the ages of eighteen and thirty. Eighteen of them were pure restrictive anorexia, and four were binge purge type. And they had no other medical comorbidities that would have been thought to affect their glucose, like diabetes, renal failure, or anything like that. And th- they on average had anorexia for 59.2 months, so almost five years, so long-standing anorexia. So their average glucose was in the normal range, but ninety-one percent of them had at least one episode of hypoglycemia less than seventy. And within the twenty-four hours, the percentage of time pers- spent below seventy was 20.82% with a maximum of fifty-two percent. So for some of these patients, they were spending up to fifty-two percent of the day with low- Yeah blood sugar. But on average, about twenty percent of the day with low blood sugar. So again, evidence of significant concern related to hypoglycemia that can have resultant complications and lead to death for that patient. And so that was basically just a descriptive study of this is what we see happening. And but doesn't tell us anything about does monitoring that help in any way? Do we know anything-- ha- have we made any difference to the patient by knowing that? 'Cause it doesn't give us any idea of what to do about it.
Sonia Singh MDSo then- I'm curious about the symptomatology. What I think of as symptoms of hypoglycemia are feeling shaky, sweaty, jittery, just needing some glucose and then having resolution with food. But if you're chronically in this state, what does that look like? Do you-- I don't know if you're-
Rebecca Berens MDyeah
Sonia Singh MDIt's not what the
Rebecca Berens MDstudy was looking at. That's a great question. And so one thing that's commonly seen in patients with anorexia is they do not feel symptoms of hypoglycemia. Because your body has adapted to being chronically low. Yeah. And that's why it's so dangerous, because they don't know.
Sonia Singh MDRight.
Rebecca Berens MDAnd and that's why the risk of death is so high because you don't know that it's happening. And so you can have th- this drop that eventually can lead to death. Because it's... If you're not feeling anything you may not feel anything until the point of you have a seizure or you go into a coma, which can happen- Yeah with severely low blood sugars. And so I think that's one kind of thought process behind like how can-- what could we use this data for? Can this help us identify who's experiencing that and intervene such that we can improve outcomes? And I think that's where we don't have that data yet. But- Yeah but this is an initial step towards like maybe this is something we can do to better help these patients.
Sonia Singh MDYeah. Interesting.
Rebecca Berens MDOkay. The next study that I wanna talk about is a little bit more, More varied. So this one's called Tracking Glucose Trends, Unveiling Clinical Patterns: Insights from Continuous Glucose Monitoring in Patients at the Extremes of BMI and Eating Disorders Pathology. And so this one's also from Europe. And this one, again, very small, 30 patients. 15 of them had anorexia, 15 of them had binge eating disorder. So again, like the opposite extremes of eating disorder pathology- or behavioral pathology. So they were wearing continuous glucose monitors while while synchronously collecting data on their food intake to correlate with that. And the CGM output was extracted and correlated with their nutritional intake, their dai- daily meals, and their self report. The interesting thing about this was they used different CGMs for the different populations. Okay. Which I felt was a little bit, makes it harder to interpret, but it was a necessity based on their situation, so the the individuals with binge eating disorder had the Dexcom G6, which is a continuous real-time CGM versus the patients with anorexia had an intermittently scanned CGM by FreeStyle Libre which I think was one of the older models that you had to actually scan it- to get the data to pull. It didn't just automatically report. And this was done because for the patients with anorexia they didn't want them to see the data. I see. Because it would influence maybe their behaviors. I
Sonia Singh MDsee.
Rebecca Berens MDOkay and They wanted to remove that variable they wanted it to go to a caregiver. But then it's hard-- You can't compare the two necessarily- Not the same anymore because they're different. It's different situations, right? But anyway and let me see. So what they saw for this was that 74% of the participants did experience hypoglycemia with unique trends based on their diagnosis. So for patients with anorexia, they had prolonged hypoglycemia between meals and including overnight, w- where versus with binge eating disorder, they did have hypoglycemic episodes, but they tended to be short-lived and typically postprandial. After eating a meal, they were getting a kind of an exaggerated insulin response and then a dip in their blood sugar to a hypoglycemic range during the day after eating. So just again, this is describing the differences in how we might see blood sugar trends in these diagnoses.
Sonia Singh MDOkay. Yeah. Interesting.
Rebecca Berens MDBut again, nothing about this to say this is what we should do. I think the thought process is, Now that we know this, and this is again what's currently being studied, and we're still gonna get more data on this, is can we use this information to be able to intervene and prevent deaths in patients with anorexia? Can we use this information as helpful biofeedback advice for patients to understand, how their eating pattern is affecting their glucose, and maybe see over time how it's improving with treatment? But then there's also the potential that it might reinforce their maladaptive behavior. For the patient I mentioned at the beginning- they would get dips, and they were like, "Every time I eat, I get a dip," which is totally expected to happen during treatment for anorexia. But it becomes a concern that's anxiety pr- provoking for them, and so then they're actually not eating what they need to eat- to be able to have the appropriate- Response response. There's also, continuous monitoring while you're already struggling with eating disorder treatment. And there's... eating disorders as a feature already involve a lot of obsession about body metrics- Yeah in most cases, and so we're adding another body metric now for you to worry about. Is that beneficial, or is it harmful? I think that probably depends on the patient. Yeah and again, we don't really know yet what to do with this evidence. It gives us- some information, and at least, say if we have a patient who has anorexia, and we see their blood sugar tanking, and they can get an alarm from a CGM, maybe they can go eat, and maybe we do prevent a death or a hospitalization or something. But we don't have the data to prove that yet, at least that I could find. I could be wrong, but I think that's what's currently being explored and better studied so we can know what impact does this have that's beneficial, and what impact does this have that's maybe not beneficial.
Sonia Singh MDYeah. Honestly, it's just heartening to even hear people studying this because I think so often there's this perception of yeah, it's a technology. We just use it, yeah. It's not... y- you have to think about in each population that you're planning to use this in, what are the benefits, what are the harms, and then what actually happens when you try to do it in people? And so we often, it feels like in, the current wellness landscape, just completely skip that step and jump- Yeah st- straight to slap it on your arm, put it on, let's start using it without ever asking the question of have we even shown this benefits anybody or what the potential harms or unintended consequences might be. So let's talk about some of those. So what are some potential harms from CGMs?
Rebecca Berens MDYeah. So I think one of the first one to be watchful for is, As I mentioned, there are several things that can affect the accuracy of these devices, one of which is compression. And if you compress it, particularly while you're sleeping, you may get a low. And so there was actually a an article I found in JAMA. It's called Continuous Glucose Monitor Use: Avoiding Overuse. And I wasn't able to read the whole full text, which was quite annoying, but it had a case report of a patient who had an unnecessary hospitalization due to misinterpretation of hypoglycemic events on their CGM. And they turned out to be from compression. Based on the summary of the article that I was able to read. But they were getting alerts overnight when they were sleeping for glucoses in the 40s and 50s, which, yeah, it does sound concerning. And they were afraid to sleep so then they ended up getting a whole medical workup.
Sonia Singh MDThe hypoglycemia workup is not a small thing.
Rebecca Berens MDNo.
Sonia Singh MDLike, when patients
Rebecca Berens MDcome
Sonia Singh MDto me- It is very
Rebecca Berens MDchallenging. and they're
Sonia Singh MDlike, "I think I have hypoglycemia," I'm like, "Don't joke about that. We gotta be very specific about what exactly you're experiencing and what the glucose is- Yeah and prove it," because committing you to a true hypoglycemia evaluation is not a small thing.
Rebecca Berens MDYeah. And that to, to your point, which you alluded to earlier, but I wanna just spell out here we have to know is it hypoglycemia, and the way to prove that is with Whipple's triad. Yeah. So Whipple's triad is the patient experiences symptoms of hypoglycemia. They feel shaky, clammy, sweaty, hungry, agitated. They have a demonstrated low venous blood sugar. So your CGM doesn't count, so we have to document it with a venous sample. And then there is a resolution of symptoms with eating. So that is the requirement. And again very difficult to do that because it's very hard to be in the lab when you're having the symptoms. And so we often do end up having to rely on these less optimal measurements. But it is, like you said, a very challenging workup, and not something that you want to submit yourself to unnecessarily. Yeah. And very costly. Yeah. And anxiety provoking. This person was afraid to sleep, that's terrifying. Yes. Yes. And very harmful. Important to be aware of that potential risk. And again, it's difficult if they're having these things overnight. That's, I think, maybe why this happened is it's hard to know if were you having symptoms- When you're sleeping Right But so yeah it's just, it's a challenging case. And so we wanna make sure we're not over-diagnosing potential hypoglycemia and doing the resultant workup when it actually was not necessary. I think the other thing to be aware of is pathologizing normal fluctuation. So this is what I was talking about. If you eat something that... drink some soda or eat some refined sugar, and you have a spike in your sugar, and then it comes right back down. That's normal. That's okay
Sonia Singh MDI mean- so there, there are many people who would disagree with you. And we won't, we shall not name this entity But a certain glucose deity is out there that really strongly believes that those spikes are a problem. So I feel that I can hear... somebody who follows that entire mantra may not even have gotten this far in this episode but-
Rebecca Berens MDYeah
Sonia Singh MDI believe there are people out there that are like, "That is not normal. That is not a normal, appropriate physiologic response, and that's that's because we're eating poison, and that is not what you should be seeing." So not just for this topic, but the pathologizing of normal human physiology and normal human responses is a big problem. And it's funny because I feel like a lot of people can see it when it comes to, Or they think they can see it when it comes to mental health or something. They'll say, "That person's not... That, that doctor just wanted to put them on meds 'cause they said they had depression, but they're just in a slump. They're having a bad day. They're just grieving their mom." Whatever it is. The, "That's not a disease. They're making it a disease. It's not a disease," right? But it seems I think people have a really hard time seeing it when it comes to stuff that has objective data with it. 'Cause they're like, "But look at these numbers," Yeah. But yeah. I think this is a great example of pathologizing and fear-mongering around completely normal human physiologic response.
Rebecca Berens MDYeah. Yeah, 'cause up until, a few years ago, however many years it's been, I don't know, that we had people without diabetes putting these on, we don't know what our blood sugars were doing.
Sonia Singh MDYou're right.
Rebecca Berens MDLike like- We were
Sonia Singh MDblissfully unaware
Rebecca Berens MDso to, to say that you know that, oh, it's because of these spikes that this is happening, like, how could you possibly know that? You can't possibly know that, 'cause we didn't have this information, ever.
Sonia Singh MDYeah. And I, I've heard the claim, and I don't know if this is true, and we came across it. I've heard the claim also that, CGMs are not quite as accurate when you're looking at the numbers within the physiologic range as they are for higher- than normal blood sugars. But I don't know if that's true.
Rebecca Berens MDSo at the very, very extremes, like very low and very high, it's actually more inaccurate.
Sonia Singh MDOkay,
Rebecca Berens MDbut the other thing is that the absolute number is not necessarily accurate. It's the trend. And which is the same as we talked about with the h- with the fitness tracker. So that's the thing is it's if it tells you your baseline is 80, and it tells you next month that your baseline is 85, and you're just like, "Oh my God, my baseline went up," I'm like, "I don't know if it did."
Sonia Singh MDOkay.
Rebecca Berens MDIt may- it probably didn't. It's, but it's the trend over time that matters, and that's why I say when I see a spike, I'm like, okay, if you have a spike and it returns to normal and you go back to your baseline, I don't see how we can say that's harmful. If you have a spike and it never quite returns to baseline, and then you have another spike and it goes even higher, and now your baseline is high, and it's never come back down to normal, yes, that makes sense that's likely an issue that your body is not properly able to lower the blood sugar. But that's not what most people are seeing. Most people are seeing, "There's a spike when I eat, and then it goes back down to my baseline, and I stay at my baseline," right? So I think I think that's the other thing is what are we talking about when we say spike?
Sonia Singh MDYeah.
Rebecca Berens MDI think it's not, I don't think we're even all talking about the same thing when we use these words, and like you said the people that are talking about this on the internet w- with their various credentials or not credentials, it's like I don't know- what you even mean by that. But anyway there was a study which I appreciated because we struggled with this with the fitness trackers, like no one was studying is this har- hurting people psychologically. Yes. But there was a study I found that understanding the benefits and psychological burdens of using continuous glucose monitoring for- Oh lifestyle change. So I was like, "This is great," because- that's exactly what we're talking about. So this was a digital questionnaire adminis- administered to adults with and without diabetes, not on insulin. So no one had insulin, but some of them had diabetes, who had used a CGM in the last year. So tricky because this is retrospective, right? This is not a controlled thing. These are all people who did use it. And so these
Sonia Singh MDpeople independently, like they chose to use this, like they, they went out and got a CGM and used it, or they were, given
Rebecca Berens MDone? They had used one, and I actually, I don't remember how they found these people, but yes, they had already used one
Sonia Singh MDindependently. I'm just wondering if they're self-selecting. Yes. They're, if this is a population that chose to go out and buy a CGM and put it on when
Rebecca Berens MDthey did not have to. My, my theory is yes- Okay because they didn't tell them to use it- for the study. Yes. They had already used it. Yes, okay. So either someone else had recommended- So people- it to them and they'd done it, or they went out and did it themselves. You know- Okay caveats. But, But they then rated characteristics of the participants, psychological traits, and ratings of their CGM-related distress. Which again, retrospective, so I don't know how accurate it all was, but it's just an interesting... these people were then reflecting on their experience with- Yeah the CGM. Okay? There were 56 adults. Their CGM-related distress varied widely. More than two-thirds of participants reported fear of Type 2 diabetes when they observed high glucose levels. Younger age and obesity were associated with greater distress, which I think is very important to mention, because this is exactly who I think is often being recommended-
Sonia Singh MDYeah
Rebecca Berens MDthese devices, is people who are concerned about their weight and people who are young and trying to be proactive. So they are also the people having the highest distress with using CGMs. Agreeableness was associated with greater fear and unhappiness in response to observing elevated glucose levels, and higher eating disorder symptoms correlated with distress over CGM's appearance. And a qualitative theme was that despite distress, most participants reported positive dietary or physical activity changes in response to CGM. Again, positive in their view. But to me, I was just like, "These are the highest risk patients to have an eating disorder." Young, want to lose weight, highly agreeable, maybe already have eating disorder symptoms, and using a CGM and are feeling a lot of distress, and may be fueling their dietary and physical activity changes in what may be perceived societally as a positive thing, but may actually for that person turn into something very negative when taken to an extreme as it would be in an eating disorder.
Sonia Singh MDYeah, don't wanna gloss over that. So 89% thought that... they felt as though they, they made positive dietary and/or physical- activity changes in response to the CGM. Yeah. But
Rebecca Berens MDinteresting- So they were definitely using the data. In their view, they were like, "I was taking that data, and I was making a change as a result."
Sonia Singh MDBut this study tells us nothing about any actual outcomes in terms of their objective health measures.
Rebecca Berens MDYeah. No, this was just how did they feel about using- the CGM.
Sonia Singh MDRight.
Rebecca Berens MDSo it does definitely tell us that yes, people are distressed.
Sonia Singh MDYeah. Which is interesting, 'cause they're, a lot of them are ackno- the majority are acknowledging that it caused them f- some fear and distress. But they're also like, "No, but it was good."
Rebecca Berens MDYeah.
Sonia Singh MDBut again- this
Rebecca Berens MDis
Sonia Singh MDthis is prob- it sounds like this is a self-selected population. Yes. Yeah.
Rebecca Berens MDBut that- But that's who would use it, right? That is- Yes the population we're talking to, is- The population of people who are like, "Yeah, I'm gonna go get one of those 'cause I wanna get healthier."
Sonia Singh MDThat
Rebecca Berens MDis you. And it might be hard for you.
Sonia Singh MDIt's... I- it's funny 'cause there's this phenomenon of patients that I already think are, hypervigilant and overly restrictive, and they're always the ones that want to jump on these technologies that give them more da- I'm like, "I don't want you to have any more reason to become more vigilant and more restrictive." And, they like all of those technologies because often it does give them some reason- to become more vigilant and more restrictive. And, I guess whether that translates to better health is really the root question here. But-
Rebecca Berens MDYeah. And I would argue that we have to look at health as a whole.
Sonia Singh MDYeah. So
Rebecca Berens MDif it makes your blood sugar better, but it makes your life miserable- because you're, fixated on your glucose every second of every day and "Oh, I can't eat this. Last time I ate that my glucose did this," which the other thing I think is important to note is you could eat the exact same meal every day, and every day the response would be different. You're not gonna get an identical spike based on the food that you ate, right? 'Cause there's so many other situational factors that affect- Right your glucose in that moment. But it... So I could see someone having "Okay, I'm gonna have this for breakfast 'cause it didn't do anything to my blood sugar," and then the next day they're like, "I had the same breakfast. Why did it go up higher?" "I gotta take out this thing." And it's like by the end you're like, "What can I eat?" Nothing. Yeah. And so I think it's it's very easy for this to become very rigid and extreme. And even if you are someone who maybe even has prediabetes- and you're wanting to prevent progression to diabetes, and you're, using this data that rigidly and even if it lowers your blood sugar, I don't know if there was net benefit to you.
Sonia Singh MDYeah.
Rebecca Berens MDFor your overall life. For you to have to be so focused on that and miss out on normal life.
Sonia Singh MDYeah. I wonder if before we move on, you can talk a little bit about the conversation we were having before we started recording, which is the response in patients who are chronically restricting, especially restricting carbohydrates, who then start introducing some of those foods, like what happens to their blood glucose? Because I have now... And n- now that we've been talking, I'm thinking of more and more, a few different patients that I've had who have fairly restrictive diets, and, I think the outside world would perceive them as eating really clean, and re- clean in quotes. Really healthy, like only eating real food. And- Almost universally they complain of fatigue and brain fog. And almost universally they will tell me... I remember for one of them, m- we- her cholesterol was high and we talked about trying to in- introduce oats into her diet, and she started eating the oatmeal and she was like, "I just feel so awful after I eat the oatmeal. I have this terrible slump and I just cannot recover, and I just feel like I need to lie down." And I was telling you an- another situation of a similar patient who had ketogenic diet for a long time, introduced some carbohydrates back into her diet, and complained of, "I'm having these big glucose spikes and then these big crashes, and I feel terrible. I think I'm better off not having carbohydrates in my diet." So talk a little bit about the physiology about that and what that... what comes up for you when you hear that.
Rebecca Berens MDYeah. So when you've had chronically restricted intake like for example we looked at these patients with anorexia for several years. Yeah. They are having chronically low blood sugars. Once you start s- do start eating more, or particularly if you haven't been eating carbs and now you're eating carbs, when you eat carbs you will get an insulin spike That is your normal response to take the sugar out of your bloodstream and put it in your body where it needs to go. And if you're someone who's been chronically restricted, you are going to be very much more sensitive to that insulin response than someone who is not. So- I think we talk a lot about insulin resistance, right? People who are insulin resistant, they're not responding appropriately to insulin and so they have to produce- Yeah a higher amount to lower their blood sugar. This is the opposite. You're very insulin sensitive. So you get a surge of insulin pull the sugar out of your bloodstream. Now it's over-corrected and now your blood sugar has dipped. And in extreme cases, like with extremely malnourished people who are refeeding, this is what causes refeeding syndrome. You get the insulin surge is not only pulling glucose out of the cell, but also potassium and phosphorus- are being affected. And that can cause cardiac arrhythmias, and that's why we care about this in refeeding syndrome. But for the average person who's just very restricted, what I think they're feeling is- Yeah an exaggerated insulin response to having not had carbs for a long time, and now when they have it, they're actually getting probably a postprandial or post-meal hypoglycemia, or low blood sugar- Yeah related to having eaten again after not eating consistently or enough for a while.
Sonia Singh MDSo if you were in the patient's shoes and you had this feeling, I think it's a very normal-
Rebecca Berens MDYes
Sonia Singh MDreaction to think I should just not do this 'cause this feels terrible." But in fact, based on the physiology and what you're describing, the solution is really to continue eating carbohydrates regularly in order- to not have this kind of exaggerated insulin response every time you have a carbohydrate. Exactly. Exactly. Which is... I think that's really challenging when you're being bathed in this messaging of "These spikes are bad. Carbohydrates are bad." You don't need them yeah. Ketosis is the goal. I think that's a really hard sell. I'm not sure how I'm going to be able to con- Yeah convince people of that,
Rebecca Berens MDit is a hard sell because, like you said, it is... There's constant messaging to the contrary, right?
Sonia Singh MDYes.
Rebecca Berens MDYeah. And you're telling someone to eat carbs regularly. But I have to tell you even some of my patients who don't have eating disorders who have been restricting carbs... I had one patient recently that I'm thinking of that was, so tired. Their hair was falling out. They were just not feeling good. And they weren't restricting total calories. They were eating- consistent meals. They just were really not eating much carbs. And I did, my labs that I do, and their thyroid, their T3 was low like we talked about on the thyroid episode. Yeah. You're not converting. I was like, "I think you need to eat more-
Sonia Singh MDYeah
Rebecca Berens MDcarbs." And they did. And guess what? They felt better. And- I
Sonia Singh MDmean, did that take convincing? H- I'm
Rebecca Berens MDprobably- It took possibly a year and a half.
Sonia Singh MDOkay. That makes me feel better. 'Cause I just imagine that you have had a lot of practice having that conversation, and you have had that conversation with a lot of people. But to me it's... Yeah, I feel... I know that I am going to be one voice telling them this one crazy thing, and that everything around them is going to be saying the opposite. And I can't imagine how that's going to sound to them, yeah. Or, how they're going to be able to buy into that. But yeah. When you think about the physiology, it makes sense. And now that I've, now that I can think of it in several people, I'm like, "Oh, yeah, I think that really would explain a lot of what these- Yeah people are experiencing." And I have sent a couple of people for hypoglycemia work-ups that I just- you don't wanna ignore it when you see that low sugar, yeah. But at the same time, it, it's, Especially when they're postprandial, people are just like, "Why would this be happening?" "I just ate though." You're, it... But, "And now you're telling me I need to eat more?" "How can that be?" So yeah, it's one of those tricky situations where I think it's counterintuitive, and it's- Yeah hard from the patient perspective to really get on board with that.
Rebecca Berens MDYeah. For sure. It's, it is challenging. And I hope that this episode is something that we'll shout into the void and-
Sonia Singh MDYeah
Rebecca Berens MDand someone will hear it, and it will... The tide will start to turn, and we will stop voluntarily starving ourselves.
Sonia Singh MDYeah. Somebody will take off their CGM and just- Yes put it away Yeah put it in the drawer. Okay. So what can we learn from this as doctors and humans?
Rebecca Berens MDYeah. So I think there are certainly benefits to CGMs for the right patient with the right support also, I think is key. Because I... In trying to interpret this data on your own is very challenging and can be very confusing, and so you need to have support. But there's also harm Right? So it's like everything else. It's not for everyone. It could be really beneficial for some people, it could be really harmful for other people. And so I think it's understanding the specific reason that you're using it and what you're doing with that information and how you're interpreting that information, what support you have in understanding that information. Because I could certainly see... you can buy these things over the counter without a prescription. I could see a person buy one of these devices online and upload their charts into ChatGPT and be like, "Chat, what should I do?" And I have no idea- Yeah what would come out of that. But versus having a conversation, looking at all of the variables with someone who knows them and has some lab data to understand better what's going on with them and is unders- is observing what the psychological impact might be, and being able to discuss all of that and come to a helpful solution.
Sonia Singh MDOr who also is, hopefully you get to the point where you have a relationship where that person can challenge you or push back a little bit- Yeah. Yeah because ChatGPT- Like, that's not going to happen is never gonna do that. No. I am learning really- You're always
Rebecca Berens MDthe smartest person in the world when
Sonia Singh MDyou're talking to ChatGPT and every day I am like... ChatGPT is so sycophantic. It just cannot stop gassing me up. I tell it regularly not to, and then it will still go back to it. So I guarantee you, if you uploaded that data, even if They were completely normal and you were normal a- there's nothing there for Chat to say, it would tell you, "This is a great move. It is so great that you wanna know more about your health, that you're doing this deeper dive to really get into-" what would be right for your body." That's what Chat's gonna say, yeah. 'Cause it's just always gonna build you up. But anyway I would say, for me, some of the take home points from this is especially as a doctor, and for patients, we really have no data to show that there is benefits from this thing for patients who do not have diabetes or pre-diabetes or some pathology going on in terms of metabolic syndrome or something that... And if you really think about it, you should ask yourself before you embark on one of these things or put one of them on, what is the outcome I'm looking for? Am I looking for more energy? Am I looking for less brain fog? Because there's literally no evidence that it's going to do those things, am I looking to lose weight? Also no evidence, even in those populations that have not normal blood sugars. So I think you have to ask yourself that, first of all. And then I think it's really important as a human to just check in with yourself and know yourself and say- How am I likely to respond to having this additional data? Because I have patients that will come to me and say, "Do not tell me to track anything because I will get obsessional over it, and then it will take over my brain- and then I will just do it obsessively, and I don't wanna g- fall into that rabbit hole." And I'm so grateful when they tell me that is how they are because there's a lot of times when I sense that is what is happening, and they don't quite have the insight yet to see that's what's happening and to realize, how much time and energy they're expending or how obsessive they're becoming over these little fluctuations. And so I just think, you have to really notice and check in with yourself about that as a potential harm and whether you're somebody who's likely to respond that way. I generally love data and I love intellectualizing things. I love gamifying things. This seems to me like something that would be right up my alley, and, the reason I'm not such a fan is just 'cause I don't think the evidence is there. But I think if you've been fed lots of content in marketing that suggests that there is evidence for it, you might jump at it. And I think that if I was just a non-medical person consuming stuff on social media I'd have no doubt that I would be interested in getting one. Hopefully having this fuller conversation and giving you a peek into all the reasoning that goes into whether or not we would recommend it for a patient helps people have some of that perspective.
Rebecca Berens MDYeah. And when I do talk to patients about this, another thing I commonly recommend is if they're someone who does have some evidence of benefit, like maybe they have metabolic syndrome or they have diabetes, is using it temporarily- to learn. And then once you kinda have it down, then just stop.
Sonia Singh MDYeah.
Rebecca Berens MDYou don't need to keep using it forever 'cause, one, it's expensive, and and then you're reducing the potential harm, right? 'Cause the potential harms related to psychological impact l- likely increase with prolonged use, right? 'Cause the longer you use it- Yeah the more likely something's gonna happen that for me that's weird, and then you're more likely to then be exposed to the risk of an unnecessary workup or a lot of anxiety over some weird thing that turned out to be a faulty sensor. Anything like that- Yeah could happen. And so if you use it on a temporary basis you can start to learn and understand. And then you, once you kinda have it down, then you just, you don't have to use it anymore.
Sonia Singh MDI think that's a great point. I don't think I've had... Other than insulin-dependent diabetics, I don't think I've ever had a patient that actually did use it for a very long term. Even my patients that have had success with it for type 2 diabetes or prediabetes, typically they're using it for a period of months. And like you said, they kinda get a sense of "Oh- I see the way my glucose response to dinner is so much better when I go take a walk afterwards. Yeah. And oh, I notice when I have sushi I really notice it. They make those connections, and then they know what to do from there, and they don't need to have it on all the time. And like you said, it's expensive to keep buying the sensors and the re- Yeah doing all the tracking. Yeah, I think that really is probably the best case use for these for many people I think there's a benefit from temporary use in the educational piece, and the bio- the biof- it's really biofeedback is what they get. Yeah. Rather than taking a walk and seeing no tangible, objective, result of that, they're taking the walk and seeing how it changes- Yeah the slope of their glucose curve. Okay, cool. Anything else in terms of how you would talk about it with patients?
Rebecca Berens MDThink really honing in on what are you gonna do with this information?
Sonia Singh MDYeah,
Rebecca Berens MDright. Because I think it can be really useful for learning and for seeing the impact. But I think if what you're going to do with it is say "Oh, I'm gonna learn which foods are good for me, which, and which ones aren't based on spikes," I'm... If the answer is gonna be, "I'm just gonna cut out all those foods," that is an extreme- Reaction. I think we need to talk about some nuance there. Yeah. Because, again I don't think it's useful to say cut out lots of things. I think it's useful to add other things that are missing. So even if you have a refined sugar and you see a big spike, it's "Hey, you know what? Maybe try having that with some protein and some fiber next time," and- Yeah see what's different. And then you can see it's actually not so bad. It's just the context that you're in.
Sonia Singh MDYeah. But the scary part about these is that because they're just available to anybody who wants to buy, so many people are going and getting that data, and may not really have anybody to talk to- about what that means or, for instance, suggesting changes that may be actually positive and helpful. Yeah, I think there's a lot of caveats when it comes to, how you interpret that and what you do with the results that you get.
Rebecca Berens MDYeah. I love to use these in conjunction with a dietician in those patients. Yeah. Like the patient I mentioned at the beginning who started working with a dietician and using... amazing results.
Sonia Singh MDYeah. Yeah.
Rebecca Berens MDSo much. And- Yeah they are seeing the dietician every other week. Yeah. Because like you said, it's also a lot of data. It's not practical probably for you to go over that with your doctor,
Sonia Singh MDright?
Rebecca Berens MDYeah. It's probably just not gonna happen. I do generally look at the general trends when I see my patients, but I have a lot of patients that I do see pretty frequently. But Most people are not seeing their doctor that regularly, and you have a lot of other things to cover. It's probably not something you're gonna have a lot of time to get into with your doctor. Dieticians are wonderful. Yeah. This is literally their thing. So they can review this with you. So you can always, I would definitely recommend at least working with a registered dietician if you're using this, not a random coach from the internet.
Sonia Singh MDNot a- Not
Rebecca Berens MDChatGPT nutritionist.
Sonia Singh MDNot a nutritionist who is not a not an RD.
Rebecca Berens MDYeah, someone who has a license as a registered dietician.
Sonia Singh MDYeah. Okay, where can people go for more info?
Rebecca Berens MDSo I'll be linking all of the resources from the papers that we talked about in in the Substack. And I will link also a couple of endocrine specialists that I know that have talked about these as well on their social media and might have some more insights that people can read.
Sonia Singh MDOkay, awesome. Thanks, Rebecca. Yeah, thanks. Hey, guys. Last but not least, we have a very important disclaimer. This podcast is intended for educational and entertainment purposes only. The content shared on this podcast, including but not limited to opinions, research, discussions, case examples, and commentary is not medical advice and should not be considered a substitute for professional medical evaluation, diagnosis, or treatment. Listening to this podcast does not establish a physician-patient relationship between you and the hosts. We are doctors, but not your doctors. Any medical topics discussed are presented for general informational purposes and may not apply to your individual circumstances. Always seek the advice of your own qualified healthcare professional regarding any questions you have about your health, medical conditions, or treatment options. Never disregard or delay medical advice because of something you've heard on this podcast. While the hosts are licensed physicians, the views and opinions expressed are our own and do not represent those of our employers, institutions, organizations, or professional societies with which we are affiliated. Although we do our best to stay up to date, please note that this podcast includes discussion of emerging research, evolving medical concepts, and differing professional opinions. Medicine is not static, and information may change over time. We, the hosts, make no guarantees about the accuracy, completeness, or applicability of this content, and we disclaim any liability for actions taken or not taken based on the information provided in this podcast. By listening to the Antisocial Doctors podcast, you have agreed to these terms. Thanks again for joining
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