How to Use a Continuous Blood Glucose Monitor (CGM) for Non-Diabetics

Article by Lucas Rockwood


If you’re a non-diabetic trying to improve your health and fitness and you’re wondering if one of the new breed of continuous glucose monitors (CGM) could help you, this article is for you.

Continuous Glucose Monitors (CGMs) are used to manage diabetes, but anyone interested in disease prevention and overall health can benefit from a two-week experiment wearing one of these devices.

I wore a FreeStyle Libre continuous blood glucose monitor for a month, and it had a measurable impact on my eating habits and health. So much so, that after this experiment, I stopped eating mango (my favourite fruit!) and started eating bread again after avoiding it for years.

An estimated 80 to 90% of the adult population has some type of metabolic imbalance. And while checking your blood sugar is nothing new–finger prick devices have been around for nearly 60 years and continuous monitors for decades–the new devices link to your smartphone, so they allow you to see how your food, sleep, and stress impact your blood glucose and your health in real time.

What is a CGM?

A continuous blood glucose monitor (CGM) is a device used to measure and monitor glucose levels in the blood continuously throughout the day and night. It works by inserting a small sensor just beneath the skin, usually on your abdomen or arm. The sensor is equipped with a tiny, flexible filament that measures glucose levels in the interstitial fluid, which surrounds your body’s cells.

The sensor contains an enzyme which, when it comes into contact with glucose in the interstitial fluid, undergoes a chemical reaction that produces a small electrical current proportional to the glucose concentration. This electrical current is picked up by the sensor which is connected to a transmitter above the skin. The transmitter wirelessly communicates with a receiver or a smartphone app, transmitting the glucose readings at regular intervals.

The receiver or app receives the glucose readings and processes the data to provide real-time glucose values and trends. Those readings can provide valuable insights into how different lifestyle factors, such as diet, exercise, stress, and sleep, affect blood glucose levels. A CGM can also serve as an early warning system by detecting potential abnormalities in blood glucose levels.

Learn How Foods Uniquely Impact Your Body

You’ve no doubt heard of low glycemic and high glycemic foods, but you might not know that your unique gut bacteria and metabolism respond differently. This means that a piece of fruit might be a great, low glycemic food for one person, and it might send someone else’s blood sugar into a spike. Individual differences vary wildly, and this is one of the key things you can learn from wearing a CGM. How does your blood sugar respond to your typical foods?

Energy Balance

There are many factors that contribute to your experience of energy throughout the day, but your blood glucose levels play a key role. If your levels are spiking high and then dropping low again and again—which is extremely common—you might feel fits and spurts of energy, followed by lethargy and brain fog. Learning to manage your own blood sugar can, in some cases, help you achieve steady state energy and focus throughout the day.

How To Buy A CGM

Glucose monitors are medical devices, so they fall under strict regulation. There are only two commercial manufacturers of devices: Dexcom and Abbott Labs FreeStyle Libre devices. Dexcom is too expensive and not as easy to obtain, so you’ll want to purchase a FreeStyle Libre 2 or 3. They are available online and from most pharmacies around the world.

  • Expect to pay $75 per sensor, sensors last 2 weeks
  • Freestyle Libre 2 or 3 are both great options
  • Say this to your doctor: “There is type II diabetes in my family. I’d like to do everything I can do for prevention, so I’d like to wear a CGM for two to four weeks.” If your doctor gives you a prescription, it may or may not be covered by insurance.
  • In some countries (like the USA) you’ll need a prescription to purchase online or offline. In all cases, you can still find them for online purchase.
  • If you live in a country were CGMs require a prescription, you can either order from overseas or else use a third party vendor like Veri, Levels, or Nutrisense (they sell the same device, but the cost is 20-50% more).

Don’t Be Scared!

At first glance, these devices can look a little scary—but don’t be concerned. The “needle” is a little filament, and you will feel nothing. It’s painless, safe, and simple to use. In fact, it’s far safer and much more comfortable than standard finger prick monitors that have been around for decades. Watch this video to learn how to install the device.

Once you’ve invested in a device and installed it, you want to make sure to make the most of your experiment period. Luckily, you’ll find tracking your blood glucose levels to be simple and intuitive.

  • Morning glucose – aim for less than 100 mg / dL and under 90 is even better
  • Post prandial glucose – in the one to two hours after a meal, aim for a spike of no more than 140 mg / dL, less is better
  • Stress and poor sleep – see how these affect you, we’re all different
  • Entertainment foods and snacks – see how your guilty pleasures impact your blood glucose (or not)

The FreeStyle Libre app (no cost) is very simple and intuitive. There are other companies with other apps, but most are overly complex and confusing.

Safety Disclaimer

Neither Lucas Rockwood nor YOGABODY has an affiliation with Abbott Labs. This article is for educational purposes only. If you are considering trying a CGM, please work with your doctor.