Ep. 285 Improving Metabolic Health: Lifestyle Interventions To Optimize Metabolic Health with Kara Collier, RD

Your trusted source for nutrition, wellness, and mindset for thriving health.

Get ready to venture into the realm of cutting-edge health and nutrition as I reconnect with Kara Collier, a registered dietitian and the co-founder of Nutrisense, the revolutionary continuous glucose monitor app! 

Our paths last crossed back in January of 2021, and I am thrilled to catch up with Kara again! Today, we delve deep into the ever-evolving landscape of metabolic health in 2023, exploring the pivotal role of CGM labs and glucometers in understanding our bodies. 

In today’s captivating conversation, Kara unravels the significance of measuring glucose against other metabolites, unveiling the profound impact of macros, exercise, supplements, sleep quality, life stage, and bio-individuality on our well-being. With a plethora of invaluable hacks to optimize your blood sugar, we invite you to join us on a captivating journey that will leave you empowered to take charge of your health and transform your life! 

Gear up for an enlightening conversation packed with valuable insights you will not want to miss! Prepare to be inspired and informed as we uncover the secrets to unlocking your metabolic potential!

“We want to focus on more whole foods, minimally processed, and nutrient-dense items. That rule does not change no matter what we’re tracking or paying attention to.”

– Kara Collier


  • The current state of metabolic health
  • What is leading to obesity in the US?
  • Getting your fasting glucose value below 90
  • The pros and cons of glucometers
  • Glucose monitoring and the 8020 rule
  • Tracking your data to learn about yourself
  • Hacks to improve your diet
  • The role of movement in metabolic health
  • How important is Zone 2 training for mitochondrial health? 
  • Follicular versus luteal phase and insulin sensitivity
  • The importance of protein and carbohydrates
  • Blood sugar and sleep quality

Kara Collier is the co-founder and VP of Health at Nutrisense, one of America’s fastest-growing wellness-tech startups. After becoming frustrated with the shortcomings of the traditional healthcare system, she made it her mission to help others reach their maximum health potential using modern technology & expert coaching. She is the leading authority on the use of continuous glucose monitoring (CGM) technology for health optimization and disease prevention. Kara is a Registered Dietitian Nutritionist (RDN), Licensed Dietitian/Nutritionist (LDN), and Certified Nutrition Support Clinician (CNSC).

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Ep. 132 – Continuous Glucose Monitors: Why They’re Not Just for Diabetics Anymore with Kara Collier


Cynthia Thurlow: Welcome to Everyday Wellness podcast. I’m your host, Nurse Practitioner, Cynthia Thurlow. This podcast is designed to educate, empower, and inspire you to achieve your health and wellness goals. My goal and intent, is to provide you with the best content and conversations from leaders in the health and wellness industry each week and impact over a million lives.
Today, I had the honor of reconnecting with Kara Collier. We last connected on Episode 132 in January of 2021. Kara is a registered dietitian and one of the co-founders of NutriSense, a continuous glucose monitor app. She has a strong background in clinical nutrition, nutrition technology, and entrepreneurship. Today, we spoke at great length about the state of metabolic health in 2023, the role of CGMs, labs and glucometers, why it’s important to measure glucose versus other metabolites, the impact of macros, the role of exercise, supplements, sleep quality, life stage of bio-individuality, as well as many hacks that you can utilize for your blood sugar. I hope you will enjoy this conversation as much as I did recording it.

Kara, welcome back to the podcast. It’s a pleasure to have you back on.

Kara Collier: Yeah. I’m excited to chat again.

Cynthia Thurlow: Yeah. So, it’s 2023, and the last time we spoke unbelievably, it was 2020. And so, let’s talk about the state of metabolic health, which I think we would both agree is at, like, a crisis state. We know that only 78% of Americans are metabolically healthy. Even worse, 80% of us are unaware that we have prediabetes. What do you think is contributing to this? What are your thoughts as a clinician, as someone who’s been on the ground taking care of patients that are not metabolically healthy, what do you think are the biggest contributors, especially over the last three years?

Kara Collier: Yeah. It’s certainly not getting better, as you mentioned, although I remain optimistic, [Cynthia laughs] so we can kind of tie that in at the end. There’s this minority of people who care a lot about this, and they’re growing louder and louder, and there’s lots more information out there, podcasts like this, information that are reaching what I would consider the average person. So, I’ve started to see just more people start to become interested. So, I’m optimistic that maybe if we touch base again in five years, we might be [Cynthia laughs] saying a different narrative. But that’s, like, slow and steady takes time, where if you look at a broader population, we’re in a really, really poor state of metabolic health overall. As you mentioned, it’s certainly less than 10% of the US population as a whole is considered metabolically optimal. And a lot of people are unaware, I think there are many things that are leading towards this.

One is that we just live in a more and more obesogenic environment. We live in an environment where everything is easy, where our predisposition to be lazy and to consume hyperpalatable foods is overwhelming. And if you aren’t highly motivated to break against some of these barriers. And if you aren’t disciplined, it does require discipline, which I don’t think is something a lot of humans are necessarily excelling at, then it becomes really challenging. We have a million different ways to avoid expending energy. We can take drive to basically everything. We can take the elevator; we can take the escalator. We can do all of these various activities to minimize energy consumption. We can turn the lights off with our phone. We can turn the AC off with our phone. So, we don’t even have to get up off the couch if we don’t want to. And then with the food environment, everything is hyper palatable around us. So, it creates this perfect storm where it’s really, really easy to overeat and overeat the wrong foods and overeat them all the time at any hour of the day. So, all of these things combined, in addition to, I think, what’s really happened in the last few years, is increased stress, which only escalates these things. So, we’re getting worse sleep. We’re really stressed as a society, and that makes these temptations or these things that require a little bit of discipline and intentionality even more challenging.

Cynthia Thurlow: Yeah. I couldn’t agree with you more. And it’s interesting, I was at a family wedding, and because of the pandemic, we have not had this very large Italian family together in many years and so my teenagers, who have now gotten really tall, are not recognizing half of the family because we just haven’t all been together. We’re kind of dispersed all across the United States. And it was really interesting to have conversations with people of differing age groups. So obviously, my parents’ generation, my generation, my younger cousins and their children, and everyone’s speaking the same or echoing the same concepts and concerns that why are we becoming increasingly unhealthy? Why are we seeing younger people with diabetes and not just autoimmune type diabetes, but metabolic health type diabetes, which we know type 2 is really a lifestyle related issue? And it was interesting, my older cousin is actually a physician and I said, “Don’t you remember back when were in school like a million years ago that the thresholds for glucose, as an example, were much higher?”

Like, you didn’t really worry, and I’m going to put this in air quotes, “Worry until you saw a blood sugar of 140.” That was the worrying concerning kind of modality. And yet now we’re understanding that sometimes lower is better. And prep for our podcast today, one of the things that I kind of refamiliarized myself with was really looking at the nuances, and this is where I’m directing the conversation. We’re going to start talking about home monitoring devices, glucometers, continuous glucose monitors, but the statistic of those with glucose levels of 90 to 99 mg/dL, so this is not considered to be diabetic yet are three times greater risk of developing diabetes versus levels of 83 mg/dL. And Dr. Robert Lustig, who I know our communities are both familiar with, mentioned that he fervently believes when you see a blood sugar greater than 100, metabolic syndrome is in full force and a fasting glucose over 90 is questionable. Now that is something that Dr. Lustig talks about in his book, Metabolical. He’s been a guest on the podcast. But I think for a lot of individuals that’s shocking. They think they’re safe if they’re under 100. And what we’re seeing from the research is 100 is not optimal. It’s really understanding that we want those fasting blood sugars to be lower than that. And would you agree?

Kara Collier: Yeah. Absolutely agree. And there is a lot of research to support this, despite the fact that maybe it’s not as well known or the guidelines haven’t changed yet. I’m also optimistic that one day they will change, but they tend to be very lagging those types of changes. And that’s to add to the problem we’re already talking about of our environment is also then the healthcare system has its own challenges that do not help the environment issue that we’re in. What I see over and over with the clients that are coming to us is that they reach that threshold of prediabetes, or they’re really close to that threshold, and their primary care was like, “Okay, well, we’ll recheck you in a year.” Keep eating well and exercising, and we’ll watch it where that is the perfect time to really get serious and say you’re in a state of metabolic dysfunction, right now, is when we really need to make some serious changes and you lay everything out and you start making any sort of big lifestyle improvements that you might not have done already. Whereas the narrative is, “Oh okay, well, you’re not quite diabetic yet, so we’ll just monitor it.” That’s the story we hear over and over. It’s not a one-off example. And so that’s part of the problem as well, is that we don’t take things seriously when they’re in that prediabetic range and then those ranges itself are even not set for what’s optimal. So, there’re so few people who are knowing what numbers they should be at to be really optimal. They’re tracking that and then they’re like being proactive about it. So that’s a narrative change that I think has to happen within either the healthcare system or we keep encouraging individuals to be advocates for themselves and go the more consumer led route, which is eventually what I decided to do after the frustrations within the healthcare system. But they’re all related and related to the actual number. We really recommend getting your fasted glucose value below 90 because there’s such strong evidence to suggest that you’re going to better off if that’s kind of where you’re sitting.

Cynthia Thurlow: Yeah. I think it’s important for people to understand that knowledge is power. And so, a part of my desire to have this conversation with you is to help people be their own best advocates. Because I recall in the early 2000s, the university system that I worked at, there were obviously a lot of postdocs, people that came from other countries that were MDs or PhDs that were doing postdoc research. And there was this lovely Australian gentleman that I became friends with and I remember him saying to me, “I don’t know what it is about the United States, but you guys do a really wretched job with prevention.” Really wretched, you wait for your patients to get diabetes. You wait for someone to have full blown asthma where they need steroids to control it. He said, “I don’t understand why you all don’t do a better job.” And at the time I was like, “Umm,” I didn’t really know what to think of that but retrospectively thinking back, he was absolutely correct.

And so, it sometimes takes mainstream medicine 20 years to catch up with the research. So, I want everyone that’s listening to understand that is why these kinds of discussions are important, so that you can take the information to your doctor, your NP, your PA, whoever you see, and just say, “I’m concerned about my blood sugars being in the 90s or low 100s consistently. This is a problem. What can we do to help?” And I think part of our discussion today, we’ll be talking about knowledge is power. And so, let’s talk about the differences between a continuous glucose monitor versus a glucometer. And so, for people to understand these are devices you can have in your home. I have both, and I think it’s incredibly insightful, but there are some important differences. And so that’s where I think this conversation is a great kind of starting point to help people understand how do they work differently, what different types of information do you get from the devices themselves?

Kara Collier: Yeah. Certainly, so there are pros and cons of both. If we start with kind of even more, what is traditional? What are people classically getting? It’s maybe a blood draw once a year where you’re getting a fasted glucose level and hemoglobin A1c. Once again, if you’re doing nothing, at least do that. At least get some labs at least once a year that will tell you a little bit of information. I always have my shtick about the flaws of a hemoglobin A1c. It tells your average glucose over the last three months. But it’s estimating that based off of how much glucose has been stuck to your hemoglobin molecules, which last on average 90 days. But not everybody’s red blood cells actually live 90 days. And so, there’re some flaws there where you could get a little bit inaccurate highs or lows. And then the other flaw of an A1c is that it’s just giving you that average. So, your glucose could be swinging up and down all day and your average could be good. And it’s still a good proxy for kind of how your glucose is doing, it’s better than nothing.

It’s certainly, if it’s very high, that is telling you something, but it’s not as good of information as something that you can get from the glucometer or from the CGM. So, then kind of the next step up is we could talk about the glucometers or the glucose meters. The major pro of these is that they’re cheap and they’re readily accessible. You know the cost isn’t insignificant because you do need to buy glucose strips to keep doing readings. But you can go to any CVS, Walgreens, Amazon and get one of these devices and then essentially what you’re doing is you’re pricking your finger, you’re drawing a drop of blood and then you’re seeing what that glucose reading is in real time. So major pro is you could take it with you anywhere. You can do that drop of blood wherever you want whenever you’re curious.

The major con is that you do have to prick your finger. This is a barrier for a lot of people. Can’t tell you how many diabetics I worked with before CGMs were a little bit more common, where they just would not do it. And we never knew what their glucose was because it is a little uncomfortable for some people. It’s no big deal at all, but it does tell you a lot of information. So, the major pro there is that you can kind of check what your fasted glucose is each morning. And you could do that for 10 days, and you could see what a trend is. Because, as you were mentioning, one fluctuation, one bad day where your fasted glucose value is higher does not necessarily mean that it’s consistently high. If we get a bad night of sleep and then you check it in the morning, I promise your fasted glucose is going to be higher than normal. But hopefully that bad night of sleep is a little bit of an anomaly for you. And when you get back to a normal sleep routine, you see that your fasted glucose improves. So, there’s a huge convenience factor with the glucose meters. And then the next step up is the continuous glucose monitor or the CGM. And what this is doing essentially is it’s reading your glucose 24/7 for two weeks straight.

So, the major pro for the CGM over glucometer is that you’re getting that movie picture of your glucose versus the photo snapshots. So instead of maybe trying to estimate how your glucose responded to a meal and you prick your finger an hour or 2 hours afterwards and you kind of guess what happened in between that hour or two hours, you can actually just see that exact curve. And so, you’re going to learn a lot more, much, much quicker when you see a movie versus a picture. So, I always guess that what you probably can learn in two weeks of wearing a CGM probably takes at least 100 finger pricks from a glucometer. The major con of course, is that they’re more expensive. The hardware itself is just more costly. It’s a more complicated device and so there is a price factor there. But the trade off, again, is that you’ll learn a lot more, much, much quicker, and you don’t have to prick your finger at all, so it stays on the back of your arm for that full two weeks. It’s truly painless. It’s very comfortable to wear and you get that data kind of real time without having to do any blood draws.

Cynthia Thurlow: It’s really interesting to me because I’m one of those people, I hate pricking my finger. And I had plenty of patients who would tell me the same thing. I hate it, I hate it, I hate it. And understanding that, you get a much broader bit of information from a continuous glucose monitor. And I speak very openly that I would not have known, even as someone who’s low carb, high protein diet, there are specific foods that are healthy. I mean, like, a plantain is not an unhealthy food. It doesn’t matter how I cook it. It doesn’t matter what macro sequence I eat it in. It spikes my blood sugar and not just a little bit, substantially. And I don’t feel poorly, so it’s not like I’m getting sweats or anything else or I feel sweaty or anything. And so, for me, it’s very interesting to see that complex interrelationship of nutrition, sleep quality, stress management, exercise, because we can certainly speak to the fact you can see changes on the CGM when you’re exercising.

Maybe you’re running a race, maybe you’re really pushing yourself. Maybe you’re doing high-intensity interval training or very, very complex strength training. And your body’s really in a position where it’s trying to free up extra stored glycogen to be able to utilize. So, I guess one of the most common questions I received in prep for our discussion today was and because my listeners know that I think checking a fasting insulin is critically important. They’re like, “Why are we measuring glucose but not insulin? Is that something that will eventually come to pass? Or is it just so much easier to measure glucose in the blood versus insulin?”

Kara Collier: Yeah. From a technology perspective, it’s much, much easier to measure glucose than it is to measure insulin. So, glucose is a metabolite that’s freely circulating in the bloodstream, where insulin is a hormone in the assay. Even to do a fasting insulin versus a fasting glucose level is a lot more complicated. That’s why you can’t do the point of care either with insulin. With that being said, the technological advances are very impressive and I know there’s a lot of R&D currently happening to measure not just insulin, but a lot of other interesting biomarkers. So, I’m certainly confident that at some point in time we’ll have continuous data streams for more than just glucose. The timeline of that is who knows? But it will happen one day. And so, I think in an ideal world, we would be measuring continuous insulin. We would be measuring some other factors as well. But glucose does tell us a lot about our health.

I kind of think about it as the 80:20 rule where what information is really going to shape some of these core healthy behaviors and really drive our health in the right direction. And glucose is telling you a lot about that. If you want to drill down even deeper, we certainly want to complement that with other things. I never recommend that the only thing you ever pay attention to is your continuous glucose values. That, of course, would be missing some of the bigger picture. But most of the time, things that are going to be driving us towards an insulin resistant state, it’s going to be reflected in the glucose values, and it’s going to serve as a behavior change proxy in the right direction.

Cynthia Thurlow: Yeah. And I think that’s really why I think CGMs are so valuable is, it can allow people to make decisions. Like, “Maybe I really do need to sleep more, maybe I need to do less cardio and I need to do more strength training or Zone 2, maybe I need to eat less carbohydrates.” Being able to see that if you sit down and have a meal of pasta, the net impact on your blood sugar versus a steak and broccoli. And so, this is a perfect pivot into talking about macronutrients. And so, I’ve had the honor recently of interviewing Glucose Goddess, and I think she’s done a beautiful job helping people understand that you don’t want to eat your carbs naked. And for you being on the kind of founder side and also being a registered dietitian, what are some of the common things that you will recommend to patients or clients when you’re counseling them? What are some of the pitfalls when they start monitoring their blood sugar and they realize, “Oh, well, maybe I need to have carbohydrates after I’ve had some steak or after that broccoli.” Maybe that’s the time to include pasta or rice, if that’s within your realm of possibility, depending on your nutritional paradigm that you embrace.

Kara Collier: Yeah. [chuckles] That was a great way of wording that. When it comes to macronutrients, carbohydrates, of course, is going to be what are influencing your glucose values the most? And most people come into this assuming that they’re going to have to completely eliminate carbohydrates from their diet and that’s usually not the case. As you mentioned a lot of times this is just giving you knowledge. Knowledge is power, and it’s informing you with the ability to make more mindful intentional decisions. So, for a lot of people, what we end up kind of working towards is figuring out their unique carbohydrate threshold. It’s how many carbohydrates can you consume and maintain good glucose values, good energy levels, and what types of carbohydrates and different strategies do those work in? Of course, there’s always the golden rule I want everyone to remember, which is we really want to, no matter what, whether it’s carbohydrate, protein or fat, focus on more whole foods, minimally processed, nutrient dense items.

That rule does not change no matter what we’re tracking or paying attention to. But when it comes to carbohydrates, it really runs the gamut of how many carbohydrates an individual can consume and maintain those healthy levels. So, for somebody who is completely sedentary, not doing any strength training, very minimal lean body mass, maybe they’re older, they’re probably going to have a very low carbohydrate threshold. They’re probably not going to be able to consume very many carbohydrates at all. We might be able to increase that threshold over time, but they’re likely going to start with kind of a lower base. Similarly, with someone with insulin resistance or type 2 diabetes, even their carbohydrate threshold is going to be very low because they no longer can fuel partition correctly. Whereas somebody who’s an athlete, young male with lots of lean body mass, they probably can consume a lot of carbohydrates and maintain great energy levels and great glucose values. So, it really differs. And that’s why there’s really no one size fits all optimal diet, optimal macronutrient balance.

We need to find that sweet spot and then within the greater total carbohydrates amount, we also need to figure out which carbohydrates you personally respond best to as an individual. As you mentioned, the plantain example for you personally, those are things you just don’t know until you see the data. You could be as knowledgeable as possible on this subject, but until you’ve actually tracked your own data, you don’t know those little nuances. Everyone’s going to have a high glucose spike to soda, to juice, to instant oats, things that are really processed. But for me personally, I have a very low glucose response to bananas and then higher to other fruits, which is a little counter to the normal glycemic index scale. So, it’s those little nuances you start to learn about yourself that you can then make good tradeoffs.

Maybe I have a really large glucose spike to rice, but I don’t really like rice. Then it’s like, “Well, probably won’t consume it unless it’s in a really good dish somebody is making for me.” Whereas maybe I love bananas and I suddenly learned that they’re actually okay. I can consume them a little bit more freely than maybe I previously might have thought. So, you can kind of make those tradeoffs. And then the final part is the hacks’ part. And so, you’ve learned kind of your unique responses. Maybe you do have higher glucose responses to rice, but you love rice. You’re like, “I don’t want to get rid of rice as something as part of my diet.” So, then we start to introduce what are the hacks that can make this a little bit better for you. And it’s usually the no naked carbs as you mentioned. So, consume some protein and fat before you eat the carbohydrate. So, if you’re eating the rice with a piece of steak, eat some of the steak first and then move on to the rice.

Try to avoid carbohydrates, especially those you don’t tolerate that well towards the evening. So, you might want to only have it at lunch and not at your dinner meal, and especially not if your dinner is kind of a little bit later in the day and then pair it with exercise. So maybe you normally do a morning workout, and then you have your favorite fruit and protein smoothie and you have a low glucose response, but if you skip your workout, you’re going to have a higher glucose response. So then maybe you go with a totally different meal if you know you missed your workout. So, timing things around like exercise, other macronutrients, and then the time of the day are some of the big hacks where you can kind of make those different foods work for you.

Cynthia Thurlow: Yeah. And I think that’s really helpful for people to understand. We’re not advocating that you never consume your favorite food ever again. We’re just saying be conscientious about when you choose to do so and embody some of these suggestions. I find for a lot of patients; they’re surprised to know that they’re more insulin sensitive during the day and less so at night. So, I would say when it’s light outside, you can get away with a whole lot more than you can at night. Number one, I just recently learned about soleus pushups. So, when I have patients who tell me, “I don’t have time to exercise,” I’m like, “You can still do a soleus push up.” And so, for listeners, Glucose Goddess did actually talk about this, and there is actual research around it, but you can literally be sitting at your desk and be flexing your calf and to be doing that several times an hour, and you actually have some degree of glucose disposal. So, understanding that for every excuse I’ve heard, I always try to come up with some way to be [Kara laughs] able to meet people where they are. But those kinds of easy things, I mean, we can walk after meals, timing your carbohydrate intake, making sure you’re not having a big bowl of pasta all by itself, I think those are really reasonable things. So, we just say, okay, just change one or two other things and then it will have less net impact on your blood sugar and overall metabolic health.

Kara Collier: Yeah, absolutely. And to your point about movement, little movement makes a difference. So, it doesn’t have to be this hour and half workout. If you don’t have time for that, it doesn’t have to be a three-mile walk. A little bit of movement makes all the difference. So, I live in Phoenix, Arizona. We’re entering summertime here. It’s a little hot. [laughter] So normally I like to go on at least a 15 minutes’ walk after each meal, just kind of map that out. But in the summer, I’m not going in the middle of the day when then I need to jump on a work meeting right after because I will be sweaty, guaranteed, it gets to 120 degrees here so instead, I just do a quick set of body weight squats and pushups in between meetings and after meals. And that works. That’s the movement that’s for my body’s way of kind of circulating and picking up some of that extra glucose stimulating my muscles.

Like you’re mentioning, there was that study that came out of that calf flexing, [Cynthia laughs] those little things actually matter. So, if you can build that into your routine and just make it a habit that you don’t have to think about, those are hacks when the environment is not great either. I know I have to deal with hot summers, some people have to deal with really cold winters. You can also get one of those– if you work from home a lot of my coworkers have the standing treadmill desk, little walking desk. So those are helpful hacks too. There’s always a workaround.

Cynthia Thurlow: Yeah, absolutely. And I guess one of the things that I find utterly fascinating about the human body is when we’re talking about the role of movement after eating, perhaps we can touch on what’s actually happening. Like our skeletal muscles really are these glucose disposal units, if you want to think about it that way. And helping people understand this is one of many reasons why I know we both advocate that people strength train throughout their lifetimes, that they maintain muscle mass, which maintains a degree of insulin sensitivity and how important that is. I would say it’s not just about body composition, it really is about metabolic health.

Kara Collier: Yeah, absolutely. Exercise, lean body mass, and movement in general are some of the most powerful tools not just for insulin sensitivity and metabolic health, but for longevity overall. It pretty much is going to have a positive ripple effect into every kind of area of health that you can think of. So, it’s one of the most important tools in our toolbox. But when it comes to glucose, specifically, over 80% of our circulating glucose ends up getting picked up by our skeletal muscle. And so, if you think about that, anytime you’re stimulating your muscles, so that’s why a little bit of stimulation can go a long way. Some walking, some movement, cleaning your house, doing various errands, chores, all of those things are helpful. And then also building up that skeletal muscle provides more of a sync for your glucose to go towards. And so, if you think about skeletal muscle as kind of your savings account, it provides that extra level of security that you have kind of a backup. If you want to be a little bit more flexible, maybe it’s your birthday or it’s your significant other’s birthday and you’re going out to eat and you want to indulge. Having some of that extra bit of lean body mass on your body is protective in those kinds of situations and allows you to be a little bit more flexible, but then stimulating your muscles as well, moving around kind of helps stimulate some of that glucose pickup that is happening.

Cynthia Thurlow: And do you recommend that your patients and clients strength train several days a week? What is your usual kind of set of recommendations? Because I think most women in particular love cardio and they want to do cardio all the time. They want to run 10 miles every day, they don’t want to pick up the weights, they don’t want to do Zone 2 cardio. But yet we acknowledge that each one of these can be very important for overall metabolic health.

Kara Collier: Yeah. So, it certainly depends on where you’re starting from. So, if you’re doing no strength training right now, trying to get an hour in the week is a great place to start. Start small, start somewhere where you think it’s actually realistic for you. So maybe that’s one one-hour session a week, if that’s all you can manage if you love cardio and you don’t want to get rid of it completely or if it’s two 30-minute sessions a week, that’s helpful. You can do an upper body day and you can do a lower body day or you can do a full body movement. The great thing too is there are so many apps and YouTube videos and tutorials, and things you can follow if you have no idea what to do. There are many, many resources out there to help guide you or hire a personal trainer if you’re worried about kind of an injury or doing something incorrectly. There are certainly things to overcome that barrier as well. But I think sort of an optimal dose for a non-athlete, just a person who’s trying to live a healthy, sustainable life, is to try to get strength training in three to four times a week.

So at least a 30-minute session, ideally closer to an hour session, is what I would consider pretty optimal amount of strength training for most people and then include some aerobic activity in addition to that [unintelligible [00:30:43] Zone 2, a little bit of Zone 5, and then I personally think it’s really helpful to try to do something that has coordination required in it. If we’re really talking about the kind of the optimal workout routine, if you’re stacking some of these things. So, whether it’s playing sports that require a little bit more coordinated movement or it’s dance or something more along those lines, there’re lots of classes that require coordination if you want to do more of a class version. This kind of helps stimulate both cognitive function and physical ability. Learning new movements, learning new physical skills is kind of helpful for that overall health as well.

Cynthia Thurlow: Yeah. I think it’s interesting in prep for an upcoming podcast with a brain researcher, he talks about in a recent book doing things like pickleball, that it’s important to have this hand-eye coordination, how important that is. And when I told my husband, because pickleball seems to be a thing right now,-

Kara Collier: It’s a thing, yeah. [chuckles]

Cynthia Thurlow: -we have never even played it. But were in a city recently where they had this whole pickleball tournament that was going on and I said to my husband, “Is this what middle-aged people do for fun? Is this now like the new thing?” But understanding that those sports activities, all those things like hand-eye coordination, we want to continue to stimulate our brains and not just our bodies throughout our lifetime. What is unique about Zone 2 training? Because this is now something that I think has become much more mainstream. You hear a lot of podcasters and physicians talking very openly about how important it is to find some balance. So don’t just go out and kill yourself doing HIIT, which should not be an hour long, it should be like 10 minutes. [chuckles] Helping people understand how important Zone 2 training is for our health.

Kara Collier: Yeah, absolutely. And speaking to doing excessive amount of HIIT. I have seen this so often where women come to us and they’re eating one meal a day, they’re eating almost no carbohydrates. They’re doing HIIT every single day as their go-to work out. They’re doing sauna, they’re doing cold plunge and their body is in stress overload. And their glucose values are skyrocketing to each of these stressors because they have filled their stress bucket too high and it’s overflowing. It’s kind of this idea of hormetic stressors are good, but the dose makes the poison and we can certainly overdo it. So, I don’t believe that HIIT every day, all day is the solution either. If you’re going to do only one thing, I always just recommend strength training. But if you’re looking for the optimal routine, adding in that Zone 2 can be really helpful. And really the underpinning for the why behind that is mitochondrial health. And so, Zone 2 really stimulates healthy mitochondria. And as we all learned in 6th grade biology, mitochondria are the powerhouse of the cell.

So metabolic health in general is just our whole complicated processes to balance energy. And really each individual unit that’s powering those energy sources is our mitochondria in our cells. And so, when we can keep those really healthy, that helps drive good metabolic flexibility. So, the ability to utilize fuel when is appropriate. So sometimes fat is appropriate, sometimes glucose is appropriate, sometimes ketones are appropriate. And so having healthy mitochondria help our body to understand when we need to be utilizing different fuels and switching appropriately and quickly so that we have that optimal energy system. And Zone 2 really trains that and also stimulates what’s called mitophagy. And so, autophagy got really popular. Mitophagy is the same thing, but for our mitochondria specifically. And it’s kind of that healthy cleansing, that repair system for that organelle specifically.

Cynthia Thurlow: Yeah. It’s really important and I’m so glad. I call it the triad. When I see women that are over fasting, over restricting, overexercising and hormesis is a good thing, but it’s beneficial stress in the right amount at the right time. And I find more often than not that people fall into the habit of not eating enough and thinking if they’re weight loss resistant, if they exercise harder, longer, more strenuously, that somehow that is going to be the antidote for what they’re struggling with. And I think that in many ways this is where a CGM can if someone’s saying to me, like, “I just always see these high blood sugars and I’m 120 pounds, I don’t understand why this is happening.” Helping them understand that if your body perceives that there is too much stress going on and your cortisol levels are up, well, guess what happens? Your blood sugar also goes up and so that glucose will go up and it can show up on that CGM.

It can show up in many other ways. But understanding that this role of hormesis or hormetic stress in people that are just– it’s like the extreme of everything. I have to sit in an ice bath for an hour and I have to do all the infrared sauna and I have to do all these strenuous activities, whether it’s just to prove themselves they can handle it, or they saw someone suggesting that one minute of cryotherapy or one minute or two minutes of cryotherapy is beneficial. And it is, but in the right person at the right time. And so, I’m so grateful that you brought that up because that’s definitely something that I’ve seen in kind of the fasting space that there are a lot of people. I always say fasting is good to a point and then it can become detrimental if you’re doing too much of it, too much intensity at the wrong time. And this is a segue into talking about women in particular because there are gender differences when we’re looking at CGM data. And so, when you’re talking about younger women, 35 and under that have a menstrual cycle, what are some of the insights that you and your colleagues are seeing in terms of follicular phase versus luteal phase and insulin sensitivity?

Kara Collier: Yeah. Absolutely, we do see a lot of gender differences across the board. I think it was Stacey Sims who said, “Women are not small men.” So, we have a different biology, we have different hormone system, and we respond differently. So specifically, just the regular monthly menstrual cycle, we do see variations in glucose values at different times of the month. And so, this will always be a little bit personalized to the individual of how much they see this effect taking hold and kind of their unique little nuances. But typically, what we see is that we have higher glucose values during the luteal phase and then lower glucose values during the follicular phase. And so usually the reason for this is of course the hormonal changes that happen during this. So, during the luteal phase, it’s not a perfect hormone fluctuation, but we tend to have lower estrogen during that time and then progesterone is peaking. And that just normally naturally makes our body a little bit more insulin insensitive.

So, we tend to have those higher glucose values, a little bit higher responses to maybe foods you normally tolerate well. And this also tends to be the time where we have our classic PMS symptoms. So, it is an amplified effect where we’re a little bit more higher glucose values at baseline during this time. And then it’s also a time where women tend to have a more difficult time sleeping, more cravings, kind of mood swings, bloating, all of those things coming together, which maybe then lead us to reach for foods that are not as optimal for us. And then we’re seeing that even more amplified effect. So, a lot of times just the awareness of this change helps women make better decisions. When you see, oh, it is my body just doing its normal changes, normal physiological processes that are resulting in some of these emotional changes or glucose changes, then you don’t feel like you’re doing something wrong or something is wrong with you.

You see it and you’re like, “Okay, this is normal, this is expected.” And that tends to empower women to just make better choices, where this craving is just because I’m in this part of my cycle, so I’m not going to give into it. So, a lot of that is kind of knowledge is power once again, where that awareness tends to lead towards better decisions. But then on the flipside, in the follicular phase, this tends to be when we are more like a man, in that we tend to be able to put on muscle better during this phase, exercise harder, we have better glucose values, insulin sensitivity. And so that’s also powerful to know if you are really into strength training. A lot of women will hit their PRs during this phase and maybe they’ll have to drop some weight during the luteal phase. And knowing that’s okay, these are normal fluctuations is also really empowering.

Cynthia Thurlow: Yeah. And it’s interesting because I’ve always advocated that women not fast the week prior to their menstrual cycle and understanding that this is a time to be a little more gentle. You may need a little bit more discretionary carbohydrate understanding that a potato is not going to get you in as much trouble as sitting down and having, like, a massive brownie sundae that is really going to skyrocket your blood sugar. And helping women understand that if they’re noticing that there are changes throughout the month in the gym that we’re really at the beck and call of our hormones, really that’s what it comes down to and that’s normal, it’s not abnormal. Now, on the other side, women that are in perimenopause and menopause, so women that are 10 to 15 years out of menopause, late 30s, early 40s, is when it’s starting, or they’re in menopause, you probably are also seeing some changes. And women are losing insulin sensitivity as they’re getting into those perimenopause years for a variety of reasons.

Kara Collier: Yes. So, there’s a lot of research to back up that menopause is an independent risk factor for insulin resistance and high glucose values, especially high fasting glucose values. And a lot of this is due to that decline in estrogen. And unlike our menstrual cycle, it’s not coming back up, it’s going to stay declined. And so, what we really need to realize here is that that might mean that what worked for you before menopause is not going to be what works for you after menopause. And again, that’s okay. It’s not that you’re doing anything wrong. It’s not that you’ve done something bad. It’s just a natural, normal physiological changes where now maybe we need to adjust what we’re eating a little bit to match this new normal. And so, a lot of times what we’re seeing and what the research shows is that there’s this decrease in glucose disposal, glucose effectiveness, when our estrogen is lower. And so, I think it’s estimated that insulin sensitivity can decrease by 30% to 50% when we’re postmenopausal. And so, because of this, usually we tend to have a lower carbohydrate threshold at this point. So as were mentioning before, it’s really about finding your personal carbohydrate threshold. And your personal threshold can change throughout life as well.

So, this tends to be a time where you just don’t tolerate carbohydrates as well as you used to. And it might be that low carb is what works for you all the time at this point. And low carb, again, is broad on purpose because what’s low for somebody is a little bit different for maybe somebody else that’s also still considered low. The other thing that’s really important during this time is needing even more protein than we needed before because we’re having higher protein turnover, less protein synthesis ability. And so, we need to increase our protein demands, the protein we’re getting from our food even more than we might have been doing before menopause. So that’s kind of like the tradeoff is, we might need to decrease carbohydrates and then think about increasing protein even more to match it. And as I’m sure you’re aware of, and you’ve talked about many times, this can make still for very enjoyable meals, like, it doesn’t have to limit your satisfaction. It’s just something to be aware of and to get on top of, or else you’re going to lead towards more of that kind of beeline towards insulin resistant state, which is going to make it challenging to lose weight, which nobody wants. It’s not just about body composition, as you’re aware of, but that’s kind of that added bonus of adjusting to your new physiological state is that it’s going to be easier for you to maintain your weight as well.

Cynthia Thurlow: Yeah. And it’s interesting because I feel like the whole protein discussion helping women understand that we’re in a catabolic state in middle age, so our protein needs actually increase. And if we’re not on hormone replacement therapy so if you’re a woman that is chosen not to be on HRT and you have low estrogen and high follicular stimulating hormone, your body really accelerates this catabolic process. So, the other kind of piece is this loss of muscle mass with aging. So, if you’re not lifting weights and you’re not able to hit those protein thresholds, which is why I’m never a fan of sustained OMAD. I’ll just plug that in there. [chuckles] Again, my listeners definitely know that, but I just keep saying this is why we have this rhetoric. But helping women understand that our relationship with carbohydrates need to change. It doesn’t mean you never eat another carb, but you’re probably going to be much better off having it from low glycemic berries, root vegetables, non-starchy veggies, as opposed to pasta, bread, and ice cream, cake and cookies, and things that tend to be harder to limit consumption of in their totality. And so. thank you for that because I think that’s invaluable.

Now, it comes up often and so obviously lifestyle comes first. So, we’re going to talk about walking after meals or doing a soleus pushup, making sure your macros are put together properly, not eating huge meals in the evening. What have been some of the supplements that you have found in your research or your experience that have worked really well now, I’m sure that we have some common ones that we probably have both seen are very effective. Chromium picolinate seems to have not gone away. That was like in the very beginning when I was kind of pivoting from traditional allopathic medicine. Chromium picolinate seemed to be pretty popular. But I always say it’s kind of like kindergarten compared to berberine as an example I think of as graduate school. It can be helpful, but berberine is going to be much more efficacious. If someone’s really kind of struggling, maybe they’re not ready for medication, but they want to do all the things to improve their insulin sensitivity. What are the things that you generally recommend or really like?

Kara Collier: Yeah. I would definitely agree with you that berberine is what we have seen to be the most effective and kind of across the board. So, there are a lot of supplements where we see work with some people, don’t work with others. But berberine seems to be pretty effective for most individuals. So that’s a good place to start if you are seeing still slightly higher glucose values and you are doing a lot of the right things. So, the thing with berberine too is you want to take it consistently. A lot of people will take it before a high carb meal at kind of like ad hoc situations. And there are a lot of berberine supplements that are mixed with other things that are marketed as a carb tolerance supplement and we have not seen that work as well as if you’re taking it consistently. So, if you really want to kind of see those long-term improvements, try taking it for several weeks and see how your glucose values improve, twice a day typically with meals is how we see it most effective.

With that being said, depending on maybe where your Achilles heel is so to speak, you might want to take some supplements that help for stress because that’s one of the big things as you’re mentioning that we see people struggle with. It can be a lot easier for people to adjust what they’re eating to figure out the optimal exercise routine, add in the movement and then it can be a lot more challenging sometimes to really address and dig into those stressors and the cortisol issues. So, if that’s one of the driving components to somebody’s metabolic disturbances then something like ashwagandha or other stress-modulating supplements tend to be really helpful. The final thing that really works kind of universally is apple cider vinegar which is not really a supplement, but you don’t eat it on its own so it’s not really considered a food either. But that is helpful more of the pre-meal type of situation. So, if you do know you’re about to really kind of indulge in maybe more carbohydrates than you normally do, having some of that apple cider vinegar beforehand either in supplement form or just dilute it in water and drink it as a beverage, that can be really helpful for those per meal situations.

The other thing that we see with supplements is sometimes if you have a deficiency or you’re not getting enough through your food, there are certain supplements that really help improve insulin sensitivity. But if you are getting enough through food, we don’t typically see it make an additional benefit. So that’s of course some of your classics like vitamin D and fish oil, omega-3 to omega-6 fatty acid balance, but also that’s where I see the chromium be the most helpful and also zinc and magnesium. So those are things to consider if you don’t think you’re getting enough through food. If you’re not sure, you can kind of try it out and see how your glucose values change. But those can be helpful as well.

Cynthia Thurlow: Yeah. It’s interesting because I know for myself, I don’t take berberine with any regularity, but I would take it like, “Oh, I just ate gluten free brownies. Or I just had dessert after dinner.” And I found that when I was monitoring my blood sugar, if I ate a steak and then broccoli and then had a dessert, my blood sugar response was pretty minimal and I didn’t notice any appreciable difference if I changed the way I eat things and then still had the dessert and even adding in berberine as needed. So, I agree with you that I didn’t see an appreciable difference, but there are definitely patients and clients of mine that are trying to avoid getting on oral medication for their prediabetes. And so, we try to do a trial, like a three-month trial to see how they do. One supplement that I found that’s been really helpful and not nearly as strong as berberine, that’s usually better tolerated is myo-inositol, definitely helps with insulin sensitivity and it’s one of those things that also helps with sleep. And most of the women that I talk to are struggling with sleep too.

It’s kind of this you move into like peak fertile years into middle age and then all of a sudden thing that you take for granted, all of a sudden aren’t working quite as efficiently. Well, Kara, it’s always a pleasure to connect with you. I do want to talk about one last topic because it’s one that I find for a lot of people can be very insightful in terms of trying to manage their blood sugar better is sleep quality. A lot of us wear wearables, wearing Oura Rings or Whoop bands and so we get a sense of how much REM or deep sleep we’re getting. For you and your work, what have been some of the insights? Is there a minimum of sleep that you generally suggest or recommend or where you see blood sugar or glucose better controlled and how does that show up the following day for most of these patients and clients?

Kara Collier: Yeah. With sleep we really want to think about both quantity and quality. So, when it comes to quantity, tends to be a little bit of personal deviation of what is best, but anywhere from seven and a half to nine hours of sleep. So not time in bed, but of actual sleep. So, depending on how long it takes you to fall asleep and if you’re waking up at all, you need to add that time into your total in bedtime. I think a lot of people are like, “Well, I was in bed for seven hours. It’s like, well, you might have been sleeping for only six, which is certainly inadequate quantity. And then we also want to focus on quality. As you mentioned, a good proxy for this is any of the sleep trackers out there. They’re not perfect, but they’re going to give you a general idea of how your sleep quality is.

What I really want to let people be aware of, if you haven’t already mentioned this though, is that not to get hung up on the tiny little differences on your sleep trackers from day to day because the accuracy isn’t 100%. So, we see people get worried about, “I had five minutes less of deep sleep last night, and now I feel like I’m not as on today.” And it’s like that could just be noise. So, look more at the overall trends you’re seeing in your sleep tracker. If it’s consistently showing that you’re getting poor sleep scores and you’re getting minimal deep sleep over and over, that’s an important signal. But the little deviations might just be kind of noise that it’s either picking up incorrectly or who knows what’s going on there. But both of those things are really important for glucose control. And I think one of the biggest surprises that most people take away when they start using a CGM for the first time is the impact of stress and the impact of sleep and how dramatic those can be. And there’s research to back it up with the sleep as well, where a poor night of sleep, whether it’s the quantity or the quality or both, can make our glucose values almost 40% higher the next day. So, we can essentially induce a state of insulin resistance from one night of poor sleep.

The good news with that is that it’s temporary, it’s fixable. So, if you got a really bad night of sleep because you’re traveling or something was going on, you’re sick, and then you get back into a normal sleep routine immediately after, we see those glucose values normalize. Where of course, we really get into trouble just like chronic stress versus acute stress is when we’re chronically sleeping poorly, because then we’re seeing that basically state of insulin resistance every single day. And that’s where we have to fix the root cause, which is sleep. But we also need to compensate by adjusting what we’re eating and doing the next day until the sleep is fixed, because your carbohydrate threshold, your ability to process that glucose is going to be greatly reduced if we’re not sleeping well. So, for some people who maybe are new parents or there are certain situations where maybe your sleep is not going to improve overnight, then you might need to pull on that nutrition lever a little bit differently and kind of adjust how you’re eating. If you know your sleep is going to be taking a hit for a more consistent period of time, for a little bit.

Cynthia Thurlow: No, such a good point. And again, focusing in on minutiae versus the big picture, and for all of us looking at broad themes as opposed to five minutes less of deep sleep day to day, that’s really irrelevant. These are always invaluable conversations Kara. Thank you so much for your time today. Please let listeners know how to connect with you. Obviously, NutriSense is a podcast sponsor, so we will tag all of that information, but let them know how to connect with you on social media. How to connect with NutriSense overall.

Kara Collier: Yeah. You can follow me on Instagram @karacollier1, and then you can also follow @nutrisenseio on all social platforms. With our NutriSense account, we’re always putting out kind of the N of 1 stories that we’re hearing, research we’re finding interesting, different experiments to try learning. So, it’s a great place to just kind of continue learning about this subject. We also have a blog and a newsletter on our website, nutrisense.io, where you can keep kind of learning some of this information as well. And then if you’re interested in trying out a CGM, you just sign up on our website also. So, nutrisense.io, fill out a quick health questionnaire, and we take care of everything else for you. One of the most common questions we always get is, do I need a prescription from my doctor to do this? Do I need to do anything on my own? And you do not. We take care of all of that. So, all you have to do is kind of sign up on our website and then eventually the CGMs will show up at your doorstep.

Cynthia Thurlow: Awesome. Thank you again.

Kara Collier: Yeah, absolutely.

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