Before we jump ahead, it’s worth taking a moment to define and understand what is meant by metabolic health. Metabolic health is not a binary outcome or on/off switch. Metabolic thresholds don’t exist for determining whether you're metabolically healthy or unhealthy. Think about metabolic health as a continuum or spectrum. Josh Clemente, co-founder of Levels describes metabolic health as “when the body is able to produce energy effectively without harmful byproducts, such that you can perform to the maximum extent you need to and can age gracefully”.
To help shift the mental framing of being either metabolically healthy or unhealthy, we will use metabolic fitness as a term that contributes to overall metabolic health. Metabolic fitness can be thought of as performing “metabolic repetitions” to increase metabolic health. These metabolic repetitions will take the form of altering various behaviors to help keep your blood glucose stabilized day in and day out.
Postprandial glycemic response
Postprandial is synonymous with “after-meal”. For this guide, your postprandial blood glucose response is what we are referencing. Your postprandial blood glucose response is a very good indicator when it comes to metabolic health. Because your CGM is constantly feeding you data points, you can draw pretty accurate inferences into your postprandial metabolic processes. After your meals, use your libre app to measure things like rapid spikes and drops, blood glucose remaining high for longer than normal (>2hours), blood glucose falling then bumping back up, and severe drops. Your postprandial blood glucose response provides good information about your metabolic response to meals.
Glycemic or Glucose Variability
Before the use of CGMs, this term did not exist. In the past, we’ve relied on the glycemic index and glycemic load to help paint a picture of glycemic responses. These are of value and should not be discredited, but with the emergence of CGMs, we can now understand glycemic variability. Glycemic variability refers to the up and down swings of glucose throughout the day. The swings can be related to various factors such as food, stress, exercise, or sleep. Glycemic variability is an extremely important marker because it’s an independent predictor of cardiovascular death and developing diabetes in the future. Major contributors to glycemic variability are the refined carbohydrates and sugars.
Blood Glucose Levels
First, let’s take a look at your body’s set point which is your fasting blood glucose levels. When you go in for regular blood work, this is the value commonly seen on lab reports. Think of this as your baseline blood glucose value. While the “optimal” fasting blood glucose levels remain unknown, we do have “ideal” fasting blood glucose levels established by the American Diabetes Association (ADA). The ADA has broken these down into the following three categories.
- Normal: Under 100 mg/dL
- Prediabetes: 100-125 mg/dL
- Diabetes: Over 126 mg/dL
These fasting blood glucose levels are considered the standard and in our opinion these values are sub-optimal. For instance, someone could have a fasting blood glucose level in the upper 90’s and nothing further is checked because they are considered normal. Quite honestly, the upper 90's is not a great indicator of metabolic health and something deeper could be ensuing. The good news is that high blood glucose levels can be reduced through dietary and lifestyle interventions.
Our optimal blood glucose values are:
- Optimal fasting: Under 90 mg/dL
- Optimal range throughout your day: 70 mg/dL - 110 mg/dL
Post-meal glucose levels
Your post-meal glucose levels are another important value to closely monitor. Your body’s ability to return to its pre-meal state in a given time, ~ 2 hours is a good indicator of metabolic fitness.
After eating a meal, a rise in blood glucose is expected, however, eating with our methods can help keep post-meal values down. What we would like to call your attention to is monitoring your postprandial glycemic response through the Libre and Levels app.
Observing the length of time it takes your blood glucose levels to stabilize can tell us a lot about your insulin response. If your body is having trouble returning to its pre-meal level, this could be related to insulin not working properly - possibly insulin resistance occurring somewhere.
For nondiabetic individuals, the International Diabetes Federation (IDF) established a post-meal blood glucose threshold of 140 mg/dL. According to the IDF, remaining under this value after any meal and returning to your baseline within 2-3 hours, is considered normal.
Similar to the ADA fasting blood glucose levels, we think these post-meal values are set higher than they should be.
For nondiabetic individuals, we recommend staying beneath 120 mg/dL and staying below a 30 mg/dL spike from pre-meal values.
This is a term we will use and believe it's worth defining before we begin. Somatic awareness simply means being attentive and aware of your body’s physical sensations. For example, the feeling of your heartbeat after an intense workout, or something like butterflies in your stomach because you are excited or anxious. Our physical sensations come in many forms. The trick is noticing them.
We are very good about being aware of our thoughts, but not so great when it comes to listening to physical sensations in our body. These physical sensations are telling us things and this is why building somatic awareness is fundamental for health and behavior change.
A natural byproduct of the Wearable Challenge offers you help with developing your somatic awareness. Like anything, this will take time and practice. Start by associating your CGM data, various behavioral changes, and your internal states. This process of association will naturally assist your ability to cultivate somatic awareness.
Bio-individuality is another important term to acknowledge. Bio-individuality simply means your dietary blood glucose responses are going to be unique to you. An 800 person study, reported that factors like your genetics, gut motility, and microbiome contribute to your specific needs for determining best dietary practices. This rules out the one-size-fits-all solution. Participating in this challenge and wearing a CGM allows you to quickly unlock your bio-individuality and begin doing what is optimal for your body.