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Cyborg or CGM?

For those of you that follow me on social media @MendozaProgram, you will have noticed my stories related to personal data from wearing a continuous glucose monitor. So what the heck am I doing and why? Have I become a cyborg or am I just a health junkie trying to optimize my daily activities to prevent chronic disease and live a long, healthy life. I'll take the latter.

Continuous Glucose Monitors (CGM) track glucose levels throughout the day and night and can alert you if your levels go too high or low, both extremes having harmful and even fatal consequences. CGM systems take blood glucose measurements at regular intervals, 24/7, and translate them into dynamic data to show glucose direction and rate of change. They are primarily used in the treatment and management (emphasis on management) of diabetes. The body aims to keep glucose at a stable level, called homeostasis, throughout the day by utilizing hormones such as insulin and glucagon in order to reduce or increase, respectively, the amount of glucose in the bloodstream at any given time. As such, CGM data can alert the wearer of harmful directions and levels and allow for the wearer to adjust their lifestyle choices in order to balance glucose levels. Of course, in today's healthcare environment, one needs a prescription for these devices and in certain circumstances jump through insurance hoops in order to get their hands on one at an affordable price. Also, the goal of CGMs in today's health industry is not to modify lifestyles, but to regulate an insulin pump. Today, a CGM is typically connected to an insulin pump and automatically pushes insulin into the body when glucose levels get too high. The applications and guidance provided by medical professionals do not connect the lifestyle choices to the actual levels, nor do the devices interpret the data as such. It is not in the interest of the medical industry to free you from disease with lifestyle changes. No one gets paid if you simply run a mile or choose an apple instead of gummy bears.

I want to make the argument that only making these devices available after a diabetic diagnosis or medical event is too late. I am not diabetic nor have I been alarmed to any harmful glucose levels from bloodwork. So why am I wearing one?

As I have stated in previous articles, I live with the goal and theory of disease prevention, rather than treatment. Thus, I seek technology and information that may work as a hedge against the development of chronic disease or illness. Herein lies the reasoning behind my excitement and willingness to wear a CGM. With this data, I am able to see how lifestyle factors such as food, stress, exercise, and sleep can affect my glucose levels. Ok, but why glucose?

I briefly dove into how glucose is an energy source for our bodies in my We Are Engines article. It is made readily available through the ingestion of carbohydrates and provides quick fuel in times of need for explosive activities. It is easily stored through the release of insulin by the body in our liver, muscle tissue, and fat cells to be accessed in order to fuel us throughout our daily activities. However, as we all know, too much of a good thing may be a bad thing. Such is the case with glucose. Our bodies have a mechanism of storing ay excess glucose in unlimited quantities through our fat cells. Thus excess energy is "signaled" by fat cell accumulation and excess body weight. As discussed in my article discussing fat, this excess can be external or internal body fat, both being harmful. Outside the harmful and unwanted effects of storing excess energy, high and low glucose levels on a daily basis have a direct correlation with energy levels, and the ability to focus. Many struggle with energy crashes after meals or afternoon fatigue at work. These feelings and symptoms are directly correlated with your glucose levels. Too low, and you get that foggy head, lack of energy feeling. Too high and you feel jittery and unable to focus. So how do you know when your body has reached an excess or is there a way to become alert or avoid you hitting your tipping point?

Enter the CGM.

Due to the ability of the CGM to produce real-time, continuous readings directly associated with food intake, exercise, and other factors, users can close the loop and watch their body's increase and decrease in energy demand and utilization by observing their blood glucose levels. You can break down if you are in a state of metabolic flexibility or made aware of a certain lifestyle choice that has put you in a harmful position. It all comes down to managing the variability in your glucose. As stated before, the body's goal is homeostasis and chronic variability is harmful, so why not promote the food and lifestyle factors that will help it achieve this goal and avoid variation. Said another way, we want to minimize the activities that cause large spikes in glucose and those that keep it elevated for a long period of time. Chronic occurrences of these events and an elevated glucose level are known to cause a metabolic issue that our body may not be capable of bringing down our glucose called insulin resistance or hyperinsulinemia, a key symptom of metabolic disease. So what does this mean?

First off, while wearing a CGM, you will be able to see your fasted glucose level. Right off the bat, this number should be within the range of medical guidelines. From the Mayo Clinic, a fasting blood sugar level less than 100 mg/dL (5.6 mmol/L) is normal. A fasting blood sugar level from 100 to 125 mg/dL (5.6 to 6.9 mmol/L) is considered prediabetes. If it's 126 mg/dL (7 mmol/L) or higher on two separate tests, you have diabetes. Thus, from wearing your CGM, you will immediately be made aware if you have an irregular fasting blood sugar level.

However, we know there has to be a starting point in the development of the disease. As such, even if you start out at a normal baseline, the chronic elevation and chronic glucose variability may lead to irregular levels down the road and development of the disease. (For a more in-depth analysis and step by step guide explaining the development of diabetes, I suggest this article.) Therefore, this data is critical in the prevention of the disease and will give direct insight into maintaining a healthy, energetic, and focused life. So how do we apply this goal of maintaining steady glucose levels to our daily lives?

Food Choices

Our food choices have a direct impact on our blood glucose levels. As discussed in my Wait, No Calories article, the basic understanding is that different macronutrients (protein, carbohydrates, and fats) in isolation have different effects on our blood glucose levels. In order from highest to lowest impact, carbohydrates, in isolation, elevate glucose the most, then proteins, then fats. However, different combinations of macronutrients will have different outcomes, yet without being able to see the data in real-time, you will not be able to be made aware of such differences. Thus, we will seek to use this information to reduce or eliminate those foods that cause harmful glucose spikes. As a reminder, these effects are exclusive of calories. Another reason that optimizing the metabolic reaction to foods is more important than tracking calories when trying to achieve health and wellness.

Due to the body's conversion of carbohydrates into glucose, foods high in this macronutrient are the main culprit in our daily glucose spikes and crashes. Thus, it is key to measure and reduce is the severity, frequency, and duration of these glucose spikes and troughs. These waves can be associated with the energy surges and crashes we feel throughout the day. Each time carbohydrates are ingested, blood glucose increases. In order to prevent harm to the body from elevated blood sugar, the pancreas will secrete the hormone, insulin, in order to find ways to bring these levels down. Chronic elevation of blood glucose levels will force more and more insulin to be released in order to regulate blood sugar as overtime, our cells become dull to the insulin and require higher doses to produce the same effect. Remember, it is not the one time effect of this mechanism that is the danger. It is the chronic, cyclical state of elevated blood sugar and insuin secretion that begins to become the symptoms and cause of metabolic disease. Now one can see how our food system littered with highly processed foods with carbohydrates in the form of refined grains and added sugars is the main driver behind our chronic disease epidemic.

Wearing a CGM will come in handy to recognize the foods that not only spike your blood glucose but those that keep it elevated for a long period of time. You will become aware of your daily sugar levels and may realize that a carbohydrate-heavy breakfast is great in the short run but leaves you hungry and tired only a couple of hours later. In real-time you will see the increase in blood glucose and then your body's natural response to bring it down, the crash. You can even evaluate the efficiency at which your body is able to clear the spike. The shorter the duration, the better your body is able to handle these spikes. Once you recognize this, you can make an adjustment to any meals that have drastic spikes or long curves. As I stated before, there are some combinations of macronutrients that are effective at mitigating the severity and duration of the spikes. Because protein and fats do not produce such a drastic glucose reaction, incorporating some of these foods can help "flatten the curve." For example, if your daily breakfast is a bowl of oatmeal (carb), topped with berries (carb), a slice of toast (carb), and a glass of orange juice (carb), you can see how this might create a drastic glucose elevation and require a large dose of insulin to regulate. However, simply substituting the berries for nut butter (fat) or the juice for water can help reduce the effect. Most diabetics or prediabetics are advised to measure their blood glucose using a finger prick. However, this "point in time" method will cause the user to miss the spike or not be able to evaluate the duration of it without constantly pricking their finger at different time intervals. Who wants to keep making their finger bleed after each meal? With the help of a CGM, constant data is available for the entire day so the feedback loop is closed. Once a meal is consumed, you will have the data from before the meal, during the meal, and after to see its effects.

In summary, a CGM will empower you to make personally educated food choices and the ability to experiment with different macronutrient combinations in order to optimize your daily intake to provide you with long-lasting and constant energy throughout the day. Remember, different foods will have different effects on all individuals. An oatmeal cookie might not spike my glucose but may throw yours off track. Also, your stress levels, time of day, and activity will have effects. The key is observation and the beauty of it all is that it is extremely personal. This exercise should be done with all meals and daily activities to see where the most harm is being done with current habits and how they can be fixed. Speaking of exercise, movement has a direct and incredible effect on blood glucose and can be used as another tool to promote homeostasis for the body.


Glucose is a form of energy for the body. As such, there is no surprise that movement and activity will have a direct effect on the body's use and production of glucose. The mere acts of pumping blood, breathing, and cognition require an energy source. However, exercise is the best way to use any stored amounts as these efforts will force the pancreas to secrete the hormone, glucagon, in order to release glucose into the bloodstream from the liver, muscles, or fat tissue to provide the energy for the activity. One of the coolest observations while wearing a CGM is the ability to see your body's demand and utilization of glucose while exercising. There is a direct correlation between intensity and the amount of glucose required. I exercise, for the most part, in a fasted state, that is, I do not eat prior to workouts. Therefore, with my CGM, I can see the level of glucose in my bloodstream before, during, and after my workout. Due to being in a fasted state, I know that the increase in blood glucose levels has to come from storage as no external sources have been ingested. I have found, personally, that more glucose is released into the bloodstream during explosive, short term exercise such as powerlifting or high-intensity interval training (HIIT) than when I am doing longer duration, lower intensity cycling or walking. This is valuable data as one can evaluate based on their fasted glucose level and planned exercise whether you may want to eat before you workout or wait in order to maximize the clearing of stored glycogen. Said another way, if your blood glucose is low and you know you are about to go for a max lifting session, it may be valuable to eat something that will provide you with energy before your efforts. However, if you are trying to achieve a ketogenic state, you may want to engage in the HIIT exercise knowing that your performance may suffer, but you will be maximizing the glucose clearing efforts. This is beneficial for those trying to achieve metabolic flexibility by forcing the body to switch fuel sources to ketones, but that topic is for another day. The premise here is that your body will use stored glucose and even produce its own in order to provide energy to complete any exercise or activity demands. With a CGM, one can track intensity levels against glucose spikes and then utilize the data to make educated refueling and training decisions.

Although discussed in the previous section, exercise activity does not have to be intense to have an effect. Many CGM users are coming to recognize the benefits of simply taking a 10-15 minute walk after meals in order to mitigate blood sugar spikes from meals. Many observations have been made that these brisk strolls allow the body to utilize the readily available energy from the meal to support the walk rather than dipping into energy stores. This allows for the utilization of the available glucose rather than the need for the pancreas to secrete insulin to store it. As such, the CGM has allowed for a healthy activity to be created after meals as a direct result of having the data available.

Again, finger pricking during exercise is not practical, much less sanitary. Who wants to be grabbing equipment after someone has done multiple finger pricks in order to monitor their glucose during exercise? This is where these devices become extremely powerful. For those seeking increased athletic performance, the CGM allows users to monitor energy availability and can be a direct feedback loop for the cause of bonking episodes. Lastly, and my personal goal, for those that use exercise as a form of enjoyment and pursuit of a healthy lifestyle, the CGM can be a tool to "check" on metabolic health. After exercise efforts, users can see whether or not glucose was utilized, analyze if they were properly fueled, and make any adjustments needed.

For me, I like to be sure that my body is able to switch over to burning fat for energy and creating ketones so I use my CGM to see the amount of utilized glucose, then measure if there are any ketones in the bloodstream. If so, this means that my exercise sufficiently depleted my glycogen stores and my body is metabolically fit enough to switch over to ketones for energy. This metabolic flexibility is a critical component in a life free of chronic disease as individuals that have chronically elevated glucose are unable to tap into fat storage and become insulin resistant as the excess energy available is always in the form of glucose. This is why low carbohydrate diets are effective for weight loss. If the source of glucose is cut off from the source the body is forced to work through what is available in storage first. Hopefully, if not insulin resistant, the body taps into the fat cells and releases the stored glucose causing them to become smaller and, in turn, weight is lost. Without this mechanism, the individual is in a chronic state of fat storage and is on the path to metabolic disease.

As discussed above, exercise is an important element of a healthy lifestyle and can be quantified with the help of a CGM to be a key tool in the pursuit of metabolic health. Without the data, individuals succumb to the dogma of quantifying exercise through "calories" or minutes spent sweating which are not useful in making decisions to promote the ability of our bodies to tap into stored energy sources. The inability to tap into these fat stores causes stalled weight loss efforts and stress. This can be a nightmare scenario as stress is another factor that plays into blood glucose levels.


We are all told that high stress correlates to an unhealthy lifestyle and is even labeled as a cause for many metabolic diseases and coronary issues. Without the data from a CGM, one is left to ponder as to why. Measuring blood glucose throughout the day can lend insight as to how stressful situations such as client phone calls, parenting episodes, or life events may impact blood glucose levels. Remember, the name of the game is homeostasis, thus any events that cause daily imbalance throw us off and are harmful towards this goal. A critical observation of CGM users is that in times of stress, our blood glucose levels become elevated. Further, based on the severity and length of the stressful episode, glucose can be elevated to a harmful amount for extended periods of time. This chronic state of high blood glucose levels mirrors the harmful effects of having chronic, elevated glucose levels from food that causes insulin resistance, hypertension, and diabetes. Herein lies the connection between elevated stress levels and disease. Take the American population that has chronically elevated glucose levels from food and from stress and you can see how only 12% of the population is metabolically healthy. Knowing this, it is important that we work to minimize these stressful episodes in an effort to mitigate the resulting glucose impact.

Wearing a CGM can make you aware of the daily situations that cause stress and elevated glucose levels and allow for the implementation of mitigation tactics. For example, breathing exercises and meditation have been shown not only to reduce stress but reduce blood glucose levels. Thus, it might be best to do 30 minutes of meditation before a hectic morning getting the kids ready for school or taking a client phone call that you know will elevate your stress levels. You are able to influence and disarm the elevation before it happens. Further, you can implement the strategies discussed above with food and exercise to buffer your stressful environment. For example, air traffic controllers who are shown to have some of the highest job-related stress levels may benefit from incorporating a low carbohydrate diet, daily exercise, and meditation practices. Wearing a CGM will provide them with the data they need to bring down the glucose impact of their stressful activities as the stressful nature of the job is innate. However, by mitigating the effect, one can free themselves from the road to metabolic disease. Without a CGM, it would be nearly impossible to associate stress or meditation with biological functions.

I have personally incorporated these efforts in my daily life. One of my most stressful parts of my day is the morning routine with the kids. We are on a schedule to get everyone up, ready, fed, and out the door to take on the day. Thus, I have implemented a 20-minute NuCalm session to help balance my stress level before "going into battle." It is a form of meditation utilizing binaural beats that has shown on my CGM to reduce blood glucose levels. Without a CGM I would be unable to know that my daily activities outside of diet and exercise have a direct and measurable impact on my health.

Above we have discussed how food, exercise, and stress can be monitored and influence glucose levels. We know the harmful effects of chronically elevated glucose levels and the even more harmful path of developing disease such as riding the glucose roller coaster of spikes and crashes. We can start to see how insulin resistance is developed and understand the development of diabetes. Thus, the daily use of a CGM continues to prove its value. This device is powerful enough to make the user aware of the metabolic and biological impact different mental states create and further connect these mental states with the occurrence of disease. I can't think of a more useful and powerful tool that should be made available to the public in order to move the needle for a healthier, more fit population. Imagine reducing the instances of diabetes, heart attacks, stroke, stress induces arrhythmias, cancers, and the list goes on. These devices allow users to shape their daily lives around achieving optimal energy levels creating a more productive population free from the afternoon crash and releasing the caffeine IV drip we all crave. CGMs allow for the discovery of many more activities that play in the game of glucose homeostases such as sunlight, saunas, cold plunges, exposure to nature, toxins, and others. These activities can then be used as lever to increase metabolic health and well being. As stated before, these devices are currently prescribed too late in the process. They should be used as a means of disease prevention much like the hundreds of wearables out there today. I hope someday that our Whoops, FitBits, and Apple watches are equipped with this data as the impact would be incredible. Currently, there are tech companies gaining traction with the biohacking community and health optimizers such as myself that are layering the CGM data onto analytical data platforms in order to make the data more easily interpreted and accessible. I am currently working with Levels Health and their app @unlocklevles to analyze my daily glucose levels and map it against my activities. Their founder Josh Clemente has an incredible background and I encourage you to do a deep dive on their blog to learn more about their goals and metabolic flexibility. Plenty of the podcast hosts on my resources page have episodes related to their personal CGM use for further exploration. More specifically, Peter Attia, Paul Saladino, and Ben Greenfield.

I am not sure how long I will be wearing my CGM, but I am extremely fortunate to have access to the technology. Given my data-driven pursuit of metabolic health, it's going to be hard to separate myself from it. I hope to have clarified my purpose of becoming a cyborg and hopefully put my followers at ease that I am not trying to become the bionic man. I am truly on the path of optimization and have benefitted from the experience. I will keep updating my Instagram account with new findings and discoveries.

As always, thanks for reading.

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