Dev Mishra, M.D.
President, Sideline Sports Doc
Medical Director, Apeiron Life
Fellow, American Academy of Orthopaedic Surgeons
Institute For Joint Restoration, Menlo Park, CA
September 15, 2020
- Continuous glucose monitoring (CGM) is a technology that involves real-time glucose measurement without having to take a blood sample
- CGM has unquestionable benefits for a person with type 1 or type 2 diabetes, as well as those with metabolic syndrome
- A new concept is using CGM in the non-diabetic, to optimize metabolic function
- I outline my recent experience with CGM
Our metabolism is comprised of a complex set of cellular processes that result in energy production in our body. Regulation of insulin and glucose are critical to metabolic regulation. Insulin is not easy to measure, but glucose is a blood sugar that’s easily measured. For type 1 and type 2 diabetics, measuring blood sugar is a key component of health maintenance.
Continuous glucose measurement (CGM) is a technology that allows a person to monitor glucose levels in real-time, without having to prick your finger for a blood sample. This technology has been a game changer for diabetics, allowing very precise control of insulin dosing in type 1 diabetics, and monitoring response to foods and exercise for type 2 diabetics.
Why would someone who’s not a diabetic want to use a continuous glucose monitor? The theory is that getting this extremely precise data will allow someone to take steps before a problem like type 2 diabetes sets in, and by doing so you’ll lose body fat, get to your optimal body weight, and reduce your chances for chronic illnesses like heart disease, diabetes, stroke, and even Alzheimer’s disease.
I used a CGM for a couple of weeks, and presented below are my summary thoughts.
How It Works
The CGM consists of a sensor (tiny needle inserted into the skin on the abdomen or back of the upper arm), and a monitor to display readings. Inserting the sensor is easy and painless, and you don’t really notice it at all once it’s on. I used the FreeStyle Libre from Abbott. Dexcom is another popular device. I used an app called Levels to record the glucose levels and correlate the readings to food and activity.
Your most important task is to carefully record everything you eat or drink, and every exercise session you perform. If you do this, you’ll be able to see the response to what you did. As in, “ok I ate this, and my glucose went really high”, or “this exercise was really effective in lowering my glucose level”. Recording food and activity is critical.
- The system works, but you absolutely must record all your food, drink, and activities in order to get the meaningful insights to help change your behavior. If you want to optimize your glucose level you need to accurately know what helps and what hurts. This is all on you, if you’re not into recording everything you won’t get much benefit.
- For me, the largest glucose spikes came from refined wheat (a bread roll) and high fructose fruits such as dates. I had negligible spikes from fruits such as berries, or a glass of red wine.
- The effect of any carb can be reduced if the carb is part of a balanced meal consisting of protein, fat, and fiber. For example, if I had an omelette for breakfast along with the dates, my glucose change was far less than if I had the dates alone. I was very surprised to see this.
- Resistance training was extremely effective at lowering my glucose. This was another surprising finding, as previously I thought aerobic exercise was the most effective way to reduce glucose.
- My current eating habits (focus on Mediterranean flavors within the guiding principles of the South Beach Diet) are already very effective.
Should You Use Continuous Glucose Monitoring?
CGM is unquestionably helpful if you’re a type 1 or type 2 diabetic, and you’ll use the monitor under careful supervision from your physician.
If you’re not a diabetic, I believe there are several groups who will benefit from CGM.
First, if you’re truly interested in doing everything you can to optimize your glucose metabolism to improve overall health, you’ll likely get a lot of benefit from CGM.
Second, if you’re not a diabetic but fall into the category of a “prediabetic” or someone with “metabolic syndrome”, then you’ll also gain valuable insights from CGM. A substantial number of Americans fall into these categories. Remember that you have to absolutely commit to recording food and activities for 2-4 weeks.
Third, folks interested in using deep objective data to guide health decisions will probably enjoy using CGM. These are folks interested in the Quantified Self.
Finally, I believe endurance athletes will have extremely useful insights from CGM that will help guide nutrition, hydration, and training strategies to result in performance improvements.
I should also add that CGM generally requires a doctor’s prescription. Using CGM in a non-diabetic is a new concept and many primary care doctors may be uncomfortable in prescribing the device. There are companies such as Levels that are focused on CGM for the non-diabetic, if you’re interested in CGM check them out.