Why I decided to wear a continuous glucose monitor 

As someone with a health science background who has several in-law relatives with type-1 diabetes, I’ve always been pretty familiar with monitoring glucose. Although I’m not diabetic, I’ve wondered what it would be like to constantly know what’s happening with my blood sugars throughout the day, particularly when I binge on junk food or when I’m eating healthy food. Throughout my time at LifeOmic I’ve also been learning about the impact that reducing insulin levels has on my risk for a variety of conditions and diseases. Glucose control in the body is a major driving factor in lowering insulin levels over time, so the idea of wearing a continuous glucose monitor became even more intriguing to me. 

Putting a continuous glucose monitor on

Recently, I had the opportunity to try one out.  A doctor friend was willing to prescribe me the Freestyle Libre 14-day, a simple quarter-sized disc that is attached to my upper arm and that lasts for–you guessed it – 14 days. It synced easily with my iPhone, so all I had to do was get over the thought of jabbing myself with a needle, and I was all set. 

Putting it on was super simple. There was a moment of minor discomfort, but the application process was much smoother than I anticipated. Syncing with my phone was straightforward the first time and every time thereafter. My experiment was made super easy by the simplicity of the device itself, which really let me focus on the data that I was getting as a result. 

What I ate while wearing a continuous glucose monitor 

I started the test by eating as I would normally. My day 1 was on a Friday family night with pizza and a beer or two, which felt like a great way to start seeing what this little device was all about! Over the course of the weekend and early days of the following week, I simply ate how I normally would have and watched the results.  I tend to cheat more on my meals Friday and Saturday, but I take a healthier approach throughout the week. After the first several days of eating as I normally would, I started playing around with mixing and matching my foods to see what impact it would have on my blood glucose. The results were extremely interesting, if not altogether unsurprising. 

What I learned from wearing a continuous glucose monitor 

 Insight #1 – white rice – whoa! 

The first Saturday night was Sushi and other Asian-style food takeout!  I love this type of food and it’s a real treat when we get it as a family.  My meal consisted of sushi as well as some chicken and white rice, plus a nice juicy IPA to go along with it. It was a blood sugar disaster!  It was as high as 148 mg/dL within an hour.  I had the leftovers of this meal on Monday as a repeat test and had the same result, blood sugars in the high 140’s! 

While that value isn’t considered dangerous, I knew that’s not a place I personally want my body to be with any regularity. On Tuesday, I had the last bit of leftover chicken and rice, but this time paired it with a salad with spinach, walnuts, extra-virgin olive oil, and balsamic. My sugars peaked out about 20 points lower, in the mid-120’s. Insight: When eating simple carbs like white rice, pair them with healthy veggies and fats to limit the sugar spikes. 

Insight #2 – What you eat now, matters even later…sometimes much later! 

This is the one that surprised me the most and the one that had the biggest impact on my behavior going forward. After a “guys night” with my two boys where we ate an entire pizza and breadsticks while watching football, my blood sugars were much more variable throughout the following day and evening compared to days when I had a healthier dinner. This happened despite the fact that I had a healthy breakfast the morning following our pizza dinner. This really drove the point home that eating healthy is a consistency thing, because the impacts of a binge night can be felt throughout my body long after that episode. I’m not saying cheat nights or meals are bad, and I’ll still have them, but I’ll do it a bit less now that I know the effects.  

My blood sugars were variable the day after “guys night”
My blood sugars were more stable the day after a healthy dinner

Insight #3 – Break a fast the “right” way 

This one I knew, but seeing the data was fun. I regularly fast for about 16 hours, and I could tell a difference in my blood sugar spike and trough when breaking a fast with a breakfast burrito with a ton of simple carbs, compared to my normal smoothie, which is full of complex carbs, fat, and protein. The makeup of the smoothie was much friendlier on my body, and as a bonus I get about 3.5 servings or more of healthy plants. 

My blood sugars (mg/dL) when I break my fast with a carb-heavy burrito:

My blood sugars (mg/dL) when I break my fast with a healthy smoothie:

Insight #4 – My blood sugars rose in the early morning, especially if I ate a high-carb meal the night before  

I was interested to see how my blood sugars responded during the latter stages of fasting. Theoretically, in the later stages of my fast my body should go from using the glucose in my blood from my last meal, to stored glycogen in the liver, to converting stored fat into ketone bodies for energy. What I could see was, like clockwork, in the last several hours of my fast my blood sugars actually started to creep upwards. My doctor friend explained that a big part of the morning rise in glucose is due to cortisol secretion early in the morning as part of your circadian rhythm to help you wake up. This  sugar comes from the glycogen stored in your liver. How much your blood sugars go up in response to cortisol in the morning depends on your carb intake the night before. My levels were a bit higher in the mornings following a carb-rich dinner.  

Below is a good example of the last half of a 19-hour fast, where you can see my blood glucose trending up a little bit at around 7 am.  I’m very interested to see how my body responds to a longer fast, as well as what’s happening to my ketones during this time, and I plan to find all that information out as part of a research study on 24-hour fasting that we are doing here at LifeOmic in the coming months. 

So what did I take away from my little “test”?  The most meaningful thing that I can apply to my day-to-day is to focus on eating fewer simple carbs.  I always knew it was important to do that, but actually seeing the impact on how it affects me personally made it sink in a lot more.  I’ve been trying to focus on eating more proteins and fats and making the carbs that I do have be whole-grains and legumes, and other complex, low-glycemic index kinds. 

If you are up to it, and your doctor is too, you might consider wearing a continuous glucose monitor to run a little test of your own.  The resulting data might just change your life! 

 


Matt Ferguson

A kinesiologist by schooling, I've spent my entire career at the intersection of science, public health and technology. I oversee our mobile products at LifeOmic, and I'm passionate about anything that involves watersports with my tribe.

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