What I learned from wearing a CGM for 10 days.

Continuous glucose monitors are becoming all the rage these days. For those of you who are new to CGMs, they check your blood sugar every 5 minutes for about 10 days. With such frequent testing, without having to prick your finger over and over again, you are able to see real time data on how what you are eating NOW impacts your blood sugar.  

​Why should you care? Repeated suboptimal elevations in blood sugar levels can lead to inflammation and promote cellular aging. High blood sugar levels leads to the production of advanced glycation end products, otherwise known as AGEs which can lead to chronic health conditions and accelerated aging. Excessive spikes are also a risk factor for developing type 2 diabetes, heart disease, kidney disease, Alzheimer’s, etc. 
 
So I decided to try it for myself. Why? Because I love n of 1 experiments and I wanted to see how my dietary choices, my lifestyle, my exercise, and my sleep affected my blood glucose levels. I used a Dexcom G6 for 10 days. The first 5-6 days I ate as I normally would. The remainder of the days I adjusted things to try to achieve what I considered optimal glucose management. Based on research I had done (here, here, here, and here), the goals I wanted to achieve were:

1. Rarely ever go over 140mg/dL (no more than 1%) after a meal and rarely go </=60mg/dL fasted.
2. Limit time spent >120mg/dL and <140
3. Aim for levels to be <100mg/dL most of the time
4. Reduce variability in glucose levels to <20%
5. Aim for <30mg/dL rise after meals, spikes above this indicate likely too many carbs were consumed.
6. Aim for fasting levels between 70-85 mg/dL
7. Aim for post meal glucose level of <115mg/dL
8. Aim for average glucose of  <105mg/dL, ideally closer to 83mg/dL
9. Aim for pre-meal glucose of around 82mg/dL or even closer to 76mg/dL

 
So what did I learn about myself?? Well, that's what is so interesting…I learned a lot! Without the insight of the CGM I would never have this deep understanding of what I can do to tweak things to better control my blood sugar, reduce inflammation and AGEs, and ultimately support optimal health. Here is what I learned:

1. A single serving of coffee (no sugar added) spikes my blood sugar by about 20 points. Yikes!
2. Cosmic Bliss Chocolate Mint Ice Cream spikes my blood sugar much less than No Sugar Added So delicious coconut ice cream bar. 
3. Cantaloupe spikes my blood sugars very, very high. My highest spike was after eating 3 slices of cantaloupe followed by 1 slice whole grain GF bread with cold cuts, tomato, onion, and ricotta. 
4. My favorite oatmeal with chia, cinnamon, whole milk, ½ apple, handful walnuts, and 2 hard boiled eggs, only spiked my blood sugar by 15-20 points. Yay!  
5. My favorite chocolate Alter Eco Burnt Caramel or Puffed Quinoa spikes my blood sugar significantly more than Cosmic Bliss, even with only a 2 square serving. Bummer….
6. Lunch often caused the highest blood sugar spike, likely because I am more stressed from work around that time, or eat more convenience meals like sandwiches. Unfortunately, turkey sandwiches AND Alter Eco chocolate was not such a good combo for me. 
7. Organic breaded chicken tenders, organic French fries with ketchup, and cucumber salad only increased my blood sugar by 20 points. So interesting…
8. I always had my lowest spikes at dinner – likely less stress and more enjoyment in my food. 
9. A single glass of wine with dinner did not cause low blood sugars, nor a reactive spike.
10. Protein and fiber make a big positive difference in my total blood sugar spike. Duh. 
11. Walking AND breastfeeding both reduced my blood sugars after meals. 
12. Eating a moderate carb diet, not too little, and not too much, works great for me. 45-60g  per meal is seems to be my sweet spot to keep my increase to <30 points. 
13. As for data points, I met most of my goals:
    1. My average glucose was 86mg/dL. Yay!
    2. My standard variability was 12mg/dL. Yay!
    3. I spent 94% in range. Yay!
    4. Pre-meal glucose was often around 70-75mg/dL. Yay!
    5. Some meals caused >30mg/dL point increase – gotta work on that.
    6. I had four spikes >140mg/dL – yikes!
    7. With some easy dietary adjustments, my post meal spikes were often <115. Yay!
    8. My fasting levels were within 70-85 all the time. Yay!
    9. I tend to run low- mid 60’s to low 70’s often – likely because I am nursing and am quickly depleting my glycogen stores. 

 
Overall, what I learned just confirmed what I knew, but also individualized things based on ME and MY current lifestyle. Currently I am a breastfeeding mama of two, that prioritizes quality balanced meals with lots of veggies, that isn’t exercising hardcore (rather just taking long walks most days), and getting VERY bad sleep. This experiment showed me that yes, I can make sure my blood sugars are well controlled if I am more mindful of my food choices and my exercise, despite having very poor quality sleep (which unfortunately negatively impacts insulin sensitivity). Interestingly breastfeeding helps increase insulin sensitivity, so together these two factors are likely a wash at this point for me. So based on this experiment, what will I change?

1. I will switch from Alter Eco chocolate to Cosmic Chocolate Chip mint ice cream for my daily little treat. 
2. Enjoy most fruit (especially cantaloupe) either with or after meals and in smaller portions, definitely NOT before meals or on an empty stomach (which I already knew isn’t ideal)
3. Continue to eat my protein and veggies first, if the meal is not mixed, and then eat my carbs. 
4. Make sure my protein intake is adequate (not too little, not too much) and that my meals are high in fiber – which is always a good reminder, even for a dietitian! 
5. Limit/avoid caffeine. With my lack of sleep, it’s definitely not supportive. 
6. Walk or breastfeed after higher carb meals to increase insulin sensitivity and help reduce spikes >120. 
7. Eat balanced snacks more often! With low glycogen stores due to breastfeeding, I need more regular fuel otherwise I drop too low (low 60’s) and feel light headed. Three meals and 2-3 snacks is actually a good routine for a breastfeeding mama who is constantly running after her kids!
8. Take even more time at lunch to wind down before eating to help reduce my stress hormone cortisol, which also increases blood sugar levels. 
9. Use this information positively but will not let this dictate all my food choices. Enjoyment in food is part of a happy life, even if it will cause a spike. 

 
Now I am curious what will happen when I stop breastfeeding and my sleep quality improves… Maybe then I will reach for another CGM experiment!

And just for those of you who are curious, the pictures below are a fews of the meals and snacks that met all my blood sugar goals.