My Continuous Glucose Monitor Experiment
There is new research showing how differently blood sugar levels fluctuate when different people eat the same foods so I had to do an experiment on myself to learn more. I’ve had a blood glucose monitor for several years but it’s difficult to constantly prick your finger so I was very excited when continuous glucose monitors (CGMs) became available. They are only available with a physician’s prescription but there are now rental services where one can rent a monitor for 14 or more days. Sign me up I thought, so I did!
You may be wondering why should we care? Higher levels of blood sugar can lead to type II diabetes but if you are not diabetic does it matter? Yes, it does. Type II diabetes is typically diagnosed by a high fasting blood glucose level or high hemoglobin A1C. But what happens at other times of the day? When you eat, your blood sugar will raise but it should then fall back down after eating. How high it spikes or how slowly it lowers back down can impact health. Higher blood sugar levels can contribute to cardiovascular disease, kidney function, immune system response, nerve impairment, poor circulation and even erectile dysfunction!
I get my fasting blood sugar level at my annual physical so isn’t that enough information? In short, not really. That’s just one marker and it doesn’t show how your body responds to food. Some people have a high spike after eating bread and some don’t. As expected, adding fat to a meal lessens the blood sugar spike for most, but not for everyone.
In the past year, we have learned the great impact of metabolic health. Those with obesity and diabetes are at greater risk for severe implications from the SARS-Cov-2 virus and only 12% of the population are considered metabolically healthy!
One study found that the blood sugar response to the same meal varies among people. Some things that will affect the response include sleep, exercise, microbiome and other health markers.
Watch this short video to learn more: Personalized Nutrition by Weizmann Institute of Science
I was hoping to learn more with my CGM:
How steady are my levels throughout the day and while I sleep?
How do different foods and food combinations affect my blood sugar?
How does my blood sugar fluctuate during exercise and how do different sports nutrition products affect my blood sugar?
I expected that my blood sugar would be fairly steady based on my diet of high healthy fat, protein and lower glycemic carbohydrates. Overall, that was the case but a few things surprised me and a few things were reinforced, such as:
Liquid stevia drops in my matcha green tea had really no impact.
Carrots increase my blood sugar more than other vegetables, even when consumed with healthy fat.
Grainless granola (made with honey) had a lower impact than a mixture of raw seeds.
Dark chocolate at night (various dark chocolate percentages and stevia-sweetened options were tested) raises my blood sugar around bedtime, which can impact sleep.
My blood sugar does not drop on bike rides at two hours or less. Longer than two hours it will start to drop so nutrition is needed. I’ve been training with no nutrition on bike rides unless longer than two hours but it was great to see the data supported my approach.
Popcorn popped in coconut oil and topped with butter has minimal blood sugar impact. There’s that benefit from adding fat and I like a lot of it on my popcorn!
Alcohol lowers blood sugar and it doesn’t really spike later if eaten with a higher fat and lower carb meal. I did not test but I’m told that it will spike later if the alcohol is combined with higher carbohydrate meals. This would likely happen during sleep, which we don’t want.
Berberine (sometimes called the natural metformin) does reduce blood sugar levels.
Light exercise, even just a walk, reduces post prandial blood sugar spikes. This is the overall belief but it really makes a difference when you see the data!
Higher intensity exercise early in the day keeps blood sugar spikes and overall levels lower for the rest of the day.
Most of this was not surprising and I didn’t have time to test many different foods or sports nutrition products but that will be coming in phase 2!
This is just another example of why nutrition has to be individualized and not one diet is right for everyone. I will be testing another CGM shortly and another next year. I hope to have my clients use a CGM so that I can guide them towards the best diet for them. More to come on that!