What I learned from wearing a continuous glucose monitor.
Those that know me best know how fascinated I am with blood sugar. I started checking my blood glucose daily with this glucometer (purchased from Amazon) in 2016, two years following my PCOS diagnosis. And let me tell you, the results weren’t always pretty!
Since coming across this informative blog post by my favorite RD a few months back, I’ve wanted to get my hands on a continuous glucose monitor to gain more insight into my spikes, dips, and average readings throughout the day. (Pricking your finger is tedious work, and unless you’re doing it every 15 minutes, there’s a good chance you’re missing out on valuable data. Ain’t nobody got time for that, and with a CGM, the process is much simpler!)
Before we dive into all things blood sugar—like why it matters for everyone, not just diabetics—let’s chat about the logistics of a CGM and how to get one.
What is a Continuous Glucose Monitor (CGM)?
A continuous glucose monitor (CGM) is a federally-approved medical device intended for diabetics that tracks blood sugar levels in real time. The brand that I used is the Freestyle Libre System, a system that consists of two parts: a sensor (the white circle that attaches to the back of your arm and inserts a thin, flexible filament just under the skin to provide glucose readings) and a reader to scan the sensor. Rather than use the reader, I downloaded the LibreLink app and scanned with my smart phone.
How I Snagged My CGM
In the US, you can only obtain a CGM with a prescription from a doctor, which can be tricky to get if you haven’t been diagnosed with diabetes. Such a bummer, because I believe that so many people could benefit from taking a peek at their blood sugar patterns.
Luckily, the endocrinologist I’ve been seeing since pregnancy is all for preventative health and was happy to write me a prescription for two 14-day sensors. Moral of the story: Don’t be afraid to ask! The worst your doctor can say is no (which, rude). And if you’re seeing a functional medicine doc or naturopath, they’re more likely to be on board.
Because I’m not diabetic, insurance understandably did not cover the cost. I willingly paid out of pocket for the two sensors and the reader, totaling $124.96. Not bad for such a nifty contraption.
Why I Check My Blood Sugar
Now that the logistics are out of the way, I want to explain why I’m so intrigued by blood sugar in the first place! If you think a non-diabetic keeping tabs on her blood glucose is silly, you wouldn’t be the first—but maybe this statistic will change your mind:
According to the 2020 National Diabetes Statistics Report, 34.2 million Americans (that’s approximately one in ten) have diabetes. And more than one in three of us have pre-diabetes, 80% of which are undiagnosed.
One. In. Three. (Let that sink in.)
My go-to snack of tahini and stevia-sweetened dark chocolate chips on dried corn cakes doesn’t have a noticeable effect on my blood sugar.
So while we’re all up in arms about Covid-19 (for good reason), there’s another pandemic kicking our country’s ass right now—and most of us aren’t even aware of it. This is a sad reality, if you ask me, because chronic diseases like diabetes don’t just happen overnight. They sometimes take years to manifest, and can usually be prevented or reversed if caught in time.
That said, I don’t think Americans are to blame. There are a multitude of factors that have led us here, and I believe our broken healthcare system is likely one of them. Unfortunately, conventional western medicine is not designed to prevent disease, only to treat it once it’s full-blown. (I’ve heard it dubbed a “sickcare system” for this reason.) My story is a classic example.
At 21 years old, after years of disordered eating, my hemoglobin A1c results came back in the pre-diabetic range—something my doctor told me not to worry about at the time. I was young and thin, after all! *Enter eye-roll.* Had I taken measures to reverse my insulin resistance back then, though, I do wonder if I could have dodged the PCOS bullet altogether. (I was diagnosed three years later.)
Obviously, we can’t change the past—but we do have some degree of control over our future. And, knowing what I know now, I’ll do whatever I can to make sure diabetes isn’t in mine.
What Do Optimal Blood Sugars Look Like?
Over the past several years, I’ve spent hours upon hours researching this stuff, and I STILL don’t have a black-and-white answer to this question.
The American Diabetes Association defines “normal” blood sugar as less than 100 mg/dL fasting and less than 140 mg/dL two hours after eating, but it’s hard to know what is normal vs. optimal (especially since we’re living in an age where “common” does not equate to normal OR optimal). The ADA also states that non-diabetics tend to see their blood glucose stay within a range of 70-130 mg/dL—a little more helpful but still kind of vague.
Some doctors claim that occasional spikes above 130 mg/dL are no big deal, as long as your blood glucose returns to baseline within a couple of hours without dipping too low in response (a condition called reactive hypoglycemia, which can occur when your body produces too much insulin). Others argue that maintaining the flattest curve possible—with little to no spikes at all—is best for optimal health. One such person is Chris Kresser, practitioner of integrative and functional medicine, who wrote that prolonged exposure to blood sugars above 140 mg/dL causes irreversible beta cell loss (the beta cells produce insulin) and nerve damage.
Most people are in agreement about one thing, however: The less work our bodies have to do to keep our blood sugars stable, the better. Frequent spikes and dips can be very stressful on our pancreas, so my personal target range for this experiment was 70-120 mg/dL. (As you’ll soon see, maintaining this was a bit tougher than I expected!)
What I Learned About My Blood Sugar While Wearing a CGM
Finally, onto the main point of this post: my findings! Not all of these observations are news to me (as I said, I’ve been checking my BG since 2016!), but I think they’re still worth pointing out. Remember: Blood sugar is very individual and complex, and what works for me may not work for you (and vice versa). Okay, let’s jump in!
NAKED CARBS CAUSE BIGGER SPIKES.
This one is kind of a no-brainer if you think about it. But first, let me clarify what I mean when I say “naked carbs.” Naked carbs are carbs eaten alone, sans protein or fat. Like a piece of plain toast or a bowl of noodles. Both of these foods are made up of mostly carbs, and if eaten by themselves (or with other carbs), will digest quicker than, say, toast with peanut butter or noodles with meat. Why? Because fat (peanut butter) and protein (meat) slow down the absorption of glucose into your bloodstream, causing a flatter curve and therefore less of a spike. This is why most nutritionists will tell you to always pair carbohydrates with protein and fat for more stable blood sugar and longer-lasting satiety (feeling of fullness).
Not hard to understand, nor to put into practice: Who would want to eat toast without peanut butter, anyway? I rarely eat carbs without fat and protein, but the one time I did (a banana), my blood sugar responded with a sharp rise and fall, leaving me hungry again an hour later.
“PALEO” DOESN’T MEAN LOW GLYCEMIC.
There were several Paleo foods that sent my BG levels soaring, and one may surprise you more than the rest.
No. 1: Paleo flours (like tapioca flour).
This wasn’t much of a shock, but I still was a little disheartened to see my blood sugar’s response to a few “healthified” versions of some of my favorite foods. Like, for example, a Paleo chocolate chip cookie. Even though the cookie was made with grain-free flours, I doubt my pancreas could tell the difference when my blood glucose landed on 170 mg/dL at the one-hour mark!
In another instance, after consuming three slices of a 10-inch pizza made with zucchini and tapioca flour, I saw a higher spike than when I had eaten a small serving of vanilla custard a few days before. Consider my mind blown, y’all. Regardless of their Paleo label, flours of any kind just ain’t my friend.
But these paleo “treats” weren’t the only troublemakers!
No. 2: Sweet potatoes!
Everyone’s favorite tuber is a blood sugar BOMB for this girl! How depressing, right? A small sweet potato eaten with peanut butter (fat) spiked my blood glucose to 160 mg/dL. And this was post-workout, so I thought I’d be in the clear. But nope. Turns out my bod just doesn’t love them sweet taters.
However, I was able to eat a small portion of sweet potato with steak and asparagus without so drastic a spike (~130 mg/dL). And, interestingly enough, a moderate serving of white potatoes didn’t have the same negative effect on my glucose. Phew.
No. 3: Dried fruit.
I’m not sure if dried fruit is technically considered Paleo by purists, but regardless, they didn’t pass the glucose experiment test. Dates especially (like the ones in RX Bars and Larabars) set me on a blood sugar rollercoaster.
GRAINS SHOULD BE APPROACHED WITH CAUTION, BUT LEGUMES ARE A-OKAY.
See that arrow next to the number? This was the only instance in a whole month that I had a straight-up arrow, which meant my BG was very rapidly increasing.
I don’t like to deprive myself of any food group, and I do believe that grains can be a part of a healthy (and delicious) diet. My body didn’t seem to mind oats and corn, but one grain that certainly did not work for me was RICE.
I’ve known for a time that white rice is problematic, but this was the first time in a loooong while that I tested brown rice. The results were startling: After consuming a medium-sized dinner of red curry with tofu, veggies, & 1/2 cup of brown rice from our local Thai bistro, my blood sugar shot up to 194 mg/dL within the hour. My worst spike ever, as far as I know.
To put this into perspective, anything over 180 mg/dL is considered diabetic levels! Wowza.
Luckily, my insulin decided to show up to the party and the numbers started falling rather quickly after that. By the two-hour mark, I was at 130 mg/dL and at three hours, back down below 100 mg/dL. This sort of thing should NOT happen often (if ever), and I’ll definitely be staying away from rice for the foreseeable future.
Legumes, on the other hand, seemed to be tolerated just fine. Even in pasta form.
In all situations, though, portion size mattered. One slice of sourdough bread wasn’t anything to sweat over, but any more than that and my blood sugar would take off like a bat out of hell.
CAFFEINE MAY CAUSE HIGHER GLUCOSE LEVELS. AND STRESS DEFINITELY DOES.
I noticed some wonky blood sugar readings on days that I drank more coffee than usual. This might be because caffeine promotes the production of our stress hormones (cortisol and epinephrine), and the liver responds by releasing glucose into the bloodstream. On top of that, less insulin is produced to curb the spike. The human race is still alive and kickin’ today thanks to this ancient survival mechanism, because glucose in the bloodstream gave us the burst of energy we needed to outrun and outsmart predators that wanted to eat us.
We no longer live in a world where we need to escape lions, thankfully, but our body doesn’t know that. So when our stress goes up, so does our blood glucose. Run, Forrest, run!
BUT A GLASS OF WINE MAY DO THE OPPOSITE.
From what I observed, a glass or two of wine with dinner may help curb spikes in the short-term. Makes sense, as the liver produces less glucose while metabolizing alcohol—but there’s not enough information to conclusively say how regular alcohol consumption affects blood glucose in the long term.
A note on alcohol and health in general: Although there is research to support the idea that light to moderate drinking may be protective against heart disease, excessive alcohol use has been found to contribute to both inflammation in the brain and leaky gut—both of which can lead to chronic diseases over time.
Also, the type of alcohol makes a difference. Red wine may have more heart-healthy benefits than other forms of alcohol because of the antioxidant component, and as mentioned, it won’t spike your blood sugar like carb-heavy beer and mixed drinks. Choose your drinks wisely, friends!
MY BODY DOES BEST ON A MODERATE-CARB DIET (FOR NOW).
Staying in that target range—ideal!
I know, I know. Carbs are the best! But if I’m being totally honest with myself, I feel better when I’m not eating a ton of grains, tubers, or sugar. And now I have the data to prove it: On the days that I stuck to a moderate amount of carbs—I don’t count macros, but my best guess would be 120-150 grams of carbohydrates—my BG never ventured out of my target range, and I was able to maintain a 24-hour average in the high 80s/low 90s. For a girl with a history of PCOS and insulin resistance, this is where I’m comfortable.
It’s important to note that my body will probably not always be this sensitive to carbs. As I mentioned previously, the more stress I’m up against, the more erratic my blood sugar will be. When I take into consideration the fact that my mineral stores are still depleted from postpartum AND that I’m basically operating on a low level of anxiety pretty much all the time (a result of my personality), it makes sense that my body can’t handle a lot of carbs right now.
The good news is, my dark chocolate habit is here to stay! Dark chocolate (85% and above) may actually help lower blood sugar levels in diabetics because of cacao’s rich magnesium content. If that’s not a win, I don’t know what is!
So… How Long Will You Keep This Up?
I have a few more days left on my second sensor, and I’m calling it quits after that. It’s easy for the perfectionist in me to become obsessed with my numbers—but obsessing over my health only causes unnecessary stress (which if you remember, can contribute to high blood sugar). That said, I got the information I was looking for and I know what foods I need to be careful around to meet my goals. That’s enough for now.
As critical a factor as blood sugar is in our wellbeing, I have to occasionally remind myself that good health is the means to an end—not the end itself. If I’m feeling well and doing the best I can to prioritize my health (while still living my best life), why worry?
I think that everyone should experiment with a CGM just once. And if it were up to me, ALL diabetics would have access to a CGM at all times, free of charge. Depending on who you are, having this sort of information at your fingertips could be life-changing at least and life-saving at most.
Let Me Know Your Thoughts!
Have you ever tried testing your blood glucose at home? What did you discover? Leave me a comment!
More Resources (Updated in 2022):
+ If, like me, you geek out on this sort of stuff, check out @glucosegoddess for some fascinating comparison graphs.
+ For an interesting look into how our mineral status impacts blood sugar, read this newsletter I wrote for Hormone Healing RD.
+ Want to try a CGM without a prescription? Levels and Nutrisense are two companies that are making this technology accessible to non-diabetics.