Unlocking Insights: Demystifying Your Blood Glucose with a CGM
Picture this; It’s four in the afternoon, and you’ve been working hard all day. Interactions with colleagues, copious amounts of sent emails and texts, disarming the occasional disgruntled patron, and your profession’s equivalent to completing complex geometry (thank you, Pythagorean theory), all have had your brain smoking like a 98’ Chevy Blazer that’s skipped its last five oil changes. You feel it setting in—that unmistakable feeling that could potentially turn the next social interaction into a jekyll and hyde moment. Some innocent person’s favor request flips a switch, turning you into an unpleasant jerk.
Hangry.
You’re hangry, and if only the person asking if you could “just put the cover sheets on the TPS reports” knew that your blood sugar was dropping below 80 mg/dL (stay tuned), this whole situation could’ve been avoided. More importantly, if only you could’ve known what your blood sugar was—or, more specifically, why it was at that level at that point in time—everyone would be better off. This is all thanks to an organ that, while only weighing two percent of your total body weight, consumes almost 20 percent of your daily energy. Today’s topic: blood sugar, how to measure it, and why knowing that measurement may just help you not only reduce your hangriness, but also make better food and beverage choices.
Getting Started
This whole curiosity started simply when I became aware of a more affordable and available iteration of something that has been around since the early 2000s, the continuous blood glucose monitor (CGM, for short). Once I found out that there was a CGM device that I could purchase without the need for a prescription, my mind ran wild with just how amazingly cool that was. I could not only monitor my blood glucose levels but also gain a better understanding of what certain foods, drinks, behaviors, and forms of exercise did to that metric (measured in mg/dL). Now is probably the time when most people reading ask my favorite question of all time, “Why?” It’s fairly standard for anyone going to a doctor’s physical to be asked for a blood test prior, and one of the more important metrics obtained through said test is one’s fasting blood glucose. Also important (perhaps more) is one’s A1C level, which is essentially a three-month average of blood glucose levels. The CGM measures your blood glucose continually (hence the name), and through a Bluetooth connection, it can transmit the data to your phone, providing you with a treasure trove of actionable information. Luckily for consumers, there are a variety of sensors and companies that leverage those sensors to build out their own unique platforms. Dexcom series, Medtronic Guardian, and Freestyle Libre are just a few of the hardware options out there, with companies like Nutrisense, Signos, and Levels all partnering with these brands to provide functional, intuitive, and easy to use apps to compliment the devices.
Driven by price and Google search priority, I decided to go with Nutrisense. Full transparency: I paid full price and am not affiliated with Nutrisense in any way. I paid approximately $300 for a one-month subscription, but the price per month goes down the more months you commit to up front. That one-time payment came with two 14-day Libre Sensors (Abbott Laboratories), access to the app (which you can still engage with after your membership ends), and one month of Registered Dietician insights and correspondence (which was an outstanding feature, in my opinion). I’m assuming that, with a doctor’s prescription and insurance, the price could drop substantially. You can even use an HSA to purchase these as well.
Let the Games Begin
Perhaps the most hesitation I sense from potential users of this technology is due to the imagined obtrusive nature of having a small needle in the back of your arm for a month, but after wearing one of these for two months, I can reassure you that not only is the application easy and painless, but I honestly forgot that I was wearing it for large portions of the day. Only when I received an alert on my phone to “not forget to upload your data at least once every 8 hours” did I remember I had this microneedle (3 mm in length and about the width of a sewing needle point) attached to my arm. The sensor was not only covered by a waterproof patch that stayed secure throughout many showers, but the adhesive held the sensor in place for many vigorous workouts.
Once the sensor was on, so too was my mission to discover just how this whole blood sugar/insulin response mechanism worked in regards to specific parts of my daily routine. It started with a simple experiment- comparing how my blood sugar responded to a savory breakfast versus a sweet breakfast (admittedly, I like to combine the two every now and then on a weekend). My savory breakfast was two pieces of whole grain bread, an avocado, and four scrambled eggs with “everything bagel” seasoning. My sweet breakfast was the same two pieces of whole grain bread with peanut butter and a sliced banana on top. The results were revealing; my peak blood glucose spike was about 15 points higher with the sweet breakfast (136 versus 120 mg/dL) than with the savory breakfast. By simply switching out the banana’s high glycemic load profile with the scrambled eggs, I was able to lower my spike, obtain more daily protein (which we all need), and stay satiated for much longer (avoiding the hangriness).
Contrast the “sweet breakfast” with the “really sweet breakfast”, which was comprised of 3 pancakes, some walnuts, half a sliced banana, and a serving of maple syrup, and my blood sugar took off like a rocket ship. Instead of the modest 136 mg/dL measurement from the sweet breakfast, these pancakes sent me to 193 mg/dL, which meant that as my insulin response kicked into overdrive, my blood glucose came crashing back down within two hours to below my pre-meal level. After deciding to go for a walk (albeit a bit too late to hedge against my blood sugar spike; more on that later), I started to feel ravenous and desperately searched for any kind of calories I could get my hands on. Unfortunately, the option I opted for was the leftover pizza from the night before, which, due to the additional high carbohydrate intake, sent my blood sugar right back up past it’s normal baseline. As you can see, this one five hour period is a microcosm of what the average American is dealing with on a daily basis.
Exercise’s Effects
We all know by now that exercise is good for us- better metabolic health, better cardiovascular and musculskeletal function, increased feelings of subjective well-being, better cognitive function, etc. How this fact relates specifically to our blood sugar is important, and going back to the “really sweet breakfast” example from before can help illustrate that.
When we engage in exercise, our muscles pull free floating sugar from our blood to help maintain fuel levels, so generally speaking, exercise will decrease the average person’s blood glucose from pre-exercise levels. If the timing is right for this exercise (immediately following a meal), it can be a useful tool for helping control just how high that peak will go, which then leads to a lower insulin response. Remember that we want to avoid extremes, so less gas pedal (blood sugar rise) can usually mean less slamming on the brakes (blood sugar drop from insulin release), which keeps all mechanisms in the metaphorical car happy and healthy. Knowing this, it is safe to assume that because I opted to go for that long walk over an hour after my really sweet (and very high carbohydrate) breakfast instead of immediately after, my blood sugar crash intensified.
Seeing how exercise impacts our blood sugar in real time can help us leverage it as a gas/brake mediator. This means that the more lean tissue (muscle) mass we have as an overall percentage of our overall weight, the better control we can have over our blood sugar during those occasional high carbohydrate meals. Think of lean tissue as a free floating carbohydrate “sink”, and the bigger your sink, the more your body can handle the excess carbohydrate load without overflowing onto the floor (which, in the case of how your body stores excess carbohydrates, would represent adipose tissue or fat cells).
Bottom Line
Overall, the CGM experience with Nutrisense was extremely insightful and led to some behavioral changes in my own consumption patterns. It also helped educate me as to why particular foods triggered spikes while others didn’t (i.e., my lunch versus dinner comparison video found below). Here are a couple of actionable key takeaways gleaned from this two month experiment-
Consuming meals high in protein, healthy fats, and fiber can help hedge against a blood sugar spike from the carbohydrates within that meal. (ex: eggs and/or avocado in addition to a slice of bread)
Go for a walk after a high carbohydrate meal to help lessen the overall peak in post-meal blood sugar.
Make simple, higher protein/healthy fat/fiber substitutes for higher carbohydrate snacks to help keep your blood sugar closer to baseline throughout the day. (ex: mixed nuts or add peanut butter to your apple).
If you or anybody you know would like to know more about my experience using a CGM, please don’t hesitate to reach out, or simply ask me in passing at the Fitness Clinic! Knowledge is only powerful if we decide to act on that knowledge. Obtaining data is great, but putting that data to work in order to better help you realize your potential is the ultimate goal.
Yours in health,
Sam