NutriSense Blog

Metabolic Flexibility: Everything You Need to Know to Get Started

March 24, 2021
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Metabolic Flexibility

Modern conveniences hugely impact the way we eat today. Our grocery stores stock up on processed foods promising meals in minutes.

We can use our phones to order from a seemingly limitless number of both healthy and not-so-healthy food options. In this new world of convenience, our natural ability to be metabolically flexible has changed.

When food was not as readily available, metabolic flexibility allowed our bodies to limit the impact of going long periods without eating.

Easy access to high-calorie processed foods combined with physically inactive lifestyles has directly impacted our ability to be metabolically flexible

But having that flexibility in our metabolism is essential to feeling our best and avoiding many health problems down the road.

Let's explore what metabolic flexibility really means and how it affects your overall health. 

What is metabolic flexibility?

The easiest way to explain metabolic flexibility is to use an analogy. Let's take cars for example. 

A standard car has one fuel source, gasoline. This is like someone who is metabolically inflexible.

Easy access to processed and high carbohydrate foods creates carb-dependent, metabolically inflexible people. So relying on carbs as a single fuel source means the body loses its ability to easily use fat as fuel. 

What is metabolic flexibility

A hybrid vehicle is flexible, switching between gasoline and electricity for its fuel. Sometimes it gets all its power from the electric motor, sometimes the gas engine, and sometimes both. 

In each case, the car uses its fuel sources to run as efficiently as possible. This is metabolic flexibility. Instead of gasoline or electricity, our bodies use glucose and carbohydrates as fuel.

When you are metabolically flexible, you can easily switch between fuel sources to maximize efficiency. If you have good metabolic flexibility, your body will quickly adapt to burn what it consumes.

For example, if you eat carbs, you will burn carbs for energy. If you eat fat, you will burn fat. 

When you go long periods without food, your body will continue to burn its fat stores for energy, meaning you don't have to rely on snacks. Good metabolic flexibility allows your body to switch between breaking down carbs or fat easily. 

Achieving metabolic flexibility can help you achieve:

  • Better weight maintenance
  • Increased energy levels
  • Better health
  • Lower odds of developing a metabolic disease
  • More consistent, healthy glucose levels
  • Improved sleep
  • Optimized workout performance

Metabolic flexibility vs. metabolic health vs. metabolism

metabolic health

Terms like “metabolism” and “metabolic health” can be difficult to understand at first glance. But they play a major part in understanding metabolic flexibility. 

Once you learn the role they play, it’s easier to understand why they matter so much.

What is metabolism?

Metabolism describes all the chemical processes that happen in your body to turn food and drink into the fuel that keeps you alive. All the chemical reactions that occur in your body are part of your metabolism. 

These chemical processes break down into two main categories:

  • Anabolism is the process of building and storing. An example of anabolism is when your body takes the food you eat and uses it to build organs, bone, or muscle. Anabolism uses small molecules to build larger molecules like carbs, fats, or proteins. Our bodies use these larger molecules to maintain body tissues, grow new cells, or store energy. It also needs energy for these anabolic processes to work. 
  • Catabolism is the opposite, breaking down tissues and energy stores. Catabolic processes break down large carbohydrate or fat cells to release energy. 

Your metabolism works in your body every minute of every day. It’s at the very root of your body’s ability to survive. But, it may not be working as efficiently as possible. 

Your basal metabolic rate (BMR) is the number of calories your body burns when at rest just to live.

Many factors can affect BMR, including: 

  • Gender
  • Age
  • Hormones
  • Genetics
  • Body size/weight
  • Body composition (fat/muscle ratio)
  • Diet
  • Hydration
  • Physical activity
  • Medication
  • Sleep patterns
  • Stress
  • Environment
  • Illness

The efficiency of your metabolism affects your metabolic flexibility and health. Healthy lifestyle decisions in diet, sleep routine, stress management, and physical activity help metabolic processes work effectively. 

Just as you have to work at being physically fit, you have to work at being metabolically fit.

With the right choices, metabolism efficiency improves and the body learns to be more metabolically flexible.

Metabolic health 

There is no standard definition of metabolic health. Scientists generally describe it as the absence of metabolic syndrome.

According to research published in the journal Current Hypertension Reports, metabolic syndrome affects approximately one-third of adults in the United States. 

Five conditions lead to metabolic syndrome: 

  • High blood pressure
  • High blood sugar
  • Abdominal obesity
  • Abnormal cholesterol
  • High triglyceride levels

Having three or more of these risk factors leads to a metabolic syndrome diagnosis. If all five are present, it greatly increases the chance of developing heart disease, diabetes, and stroke.  

So the main factors that lead to metabolic syndrome (being metabolically unhealthy) include physical inactivity, being overweight, age, and genetics. 

Differences between metabolic health & metabolic flexibility

Metabolic flexibility drives metabolic health.

When your body becomes metabolically inflexible, problems like high blood glucose begin affecting your metabolic health and wellness. 

Why metabolic flexibility is important for your glucose levels 

Metabolic flexibility means more energy efficiency

If you are metabolically inflexible, your glucose levels will likely go up higher than normal and stay higher for longer than they should.

You can't have optimal glucose values without being metabolically flexible. Metabolic flexibility allows you to properly utilize energy rather than inefficiently storing it.

Why metabolic flexibility is important

Weakened metabolic flexibility can lead to insulin resistance

The best example of compromised metabolic flexibility is insulin resistance. Remember, when you’re metabolically inflexible, it can lead to raised glucose levels. 

If you continue to have these high glucose levels long-term, your pancreas has to produce more insulin to manage the increase. The cells that make insulin in your pancreas then become overworked and dysfunctional. 

Over time, your cells start to ignore the persistent insulin signal and stop removing the excess glucose from your blood.

This insulin resistance can lead to long-term health problems.

Long-term metabolic inflexibility can cause serious health issues

There are several long-term health effects that result from metabolic inflexibility:

Short-term metabolic inflexibility can bring immediate negative symptoms

Not being able to use fat stores between meals leads to not feeling full. This is why metabolically inflexible people tend to snack often. 

Other short term symptoms of metabolic inflexibility include: 

  • Feeling “hangry”
  • Sleepiness after meals
  • Midday energy crashes
  • Constant caffeine intake to boost energy
  • Being overweight
  • Feelings of anxiety 

Better metabolic flexibility = reduced micromanagement

The more metabolically flexible you are, the less you have to micromanage your macronutrients and calories. Metabolic flexibility allows your body to maintain healthy glucose values without worrying too much about being “perfect” 24/7. 

If you occasionally eat a carb-laden meal that’s high in fat, your body will be able to cope with it. Your satiety signals will reset, meaning you won't feel the need to consistently snack. Your energy levels will also naturally increase. 

Metabolic flexibility and glucose are intrinsically connected. That’s why understanding your body’s relationship with glucose is key to achieving metabolic flexibility. 

See how glucose affects your metabolic flexibility in real-time
Start your journey toward metabolic flexibility by using a continuous glucose monitor (CGM). Track and analyze your body’s response to glucose, then understand the data with the help of personalized nutritionists. Sign up today.

How to get started with metabolic flexibility

How to get started with metabolic flexibility

If you're not sure how to assess and adapt your metabolic flexibility, here is a guide on how to get started:

1. Track your glucose

It’s challenging to know what is happening to your glucose levels unless you actively track them. You can’t physically see what foods make your glucose levels spike and put a strain on your cells. 

The only way to track your glucose in real-time is to use a continuous glucose monitor (CGM). It lets you actively see which lifestyle influences and foods directly impact your glucose levels.

Armed with this knowledge, you can make simple yet effective changes that improve your metabolic health. It also allows you to experiment with foods to ensure you find a nutrition plan personalized to your individual body reactions.

Tracking glucose gives you statistical data that directly shows you the impact of any lifestyle changes you make on your body.

2. Focus on your diet

Diet always affects your metabolic flexibility. Remember the phrase, “you can’t outrun a bad diet.” 

Even with regular exercise, a bad diet puts stress on your body at a cellular level. Eating whole foods and avoiding processed foods is the best place to start.

Standard American Diet

• Avoid the Standard American Diet 

The standard American diet contains excess sodium, refined grains, processed vegetable oils, and added sugars. This contributes to the fact that approximately half of all American adults have one or more preventable chronic diseases. 

To improve metabolic flexibility, focus on whole foods and minimize your added sugar and refined carbohydrate intake.

Lowering your carbohydrate intake helps to:

  • Reduce your glucose and insulin levels
  • Put less stress on your cells
  • Improve metabolism
  • Improve metabolic health 

• Try cyclical ketosis

If you’re already thinking about changing your diet or starting a new one, then cyclical ketosis might be a good option for you.

A cyclical ketosis diet involves eating a standard keto diet for most of the week but adding in periods of eating more carbs.  

The standard keto diet is a low-carb, high-fat diet. Adding in some carbohydrates to your standard keto diet brings your body in and out of ketosis. This process allows your body to use both glucose and fat as fuel to become more metabolically flexible. 

The perfect cyclical keto diet is very personal. Some people thrive with one higher-carb meal per day in their routine. Others do better by adding in one full higher-carb day per week. 

The best way to find your ideal pattern is to use a CGM so that you can assess in real-time how your body responds.

• Eat within your energy requirements

Overeating and excess energy intake, regardless of the food, can lead to inflexibility. Extra calories lead to excess glucose, which leads to insulin resistance and fat storage. 

Ensuring you eat within your energy requirements reduces this risk and improves metabolic flexibility. 

3. Get enough exercise

Physical inactivity is one of the leading causes of metabolic inflexibility. Exercise is key in fighting this because it helps control glucose levels

Studies show that exercise increases mitochondrial content, improves glycemic control, and improves insulin sensitivity. Improving insulin sensitivity helps your body maintain healthy glucose levels. 

Trying different types of workouts in your exercise routine can also assist your body to become more metabolically flexible.

Any type of exercise is beneficial. But, experts believe that incorporating a mix of aerobic cardio (zone 2 heart rate training — 60%-70% of heart rate max) and strength training gives optimal results.  Zone 2 training improves mitochondrial function while strength training promotes insulin sensitivity and glucose management.

Regardless of the type of exercise, regular muscle activation stands as a frequently recommended preventative measure against developing metabolic disease

Intermittent fasting

4. Intermittent fasting

Timing when you eat plays a pivotal role in metabolic health.

Intermittent fasting (or not eating for a set period each day of 14-24 hours) helps combat insulin resistance and improve metabolic flexibility. Fasting helps to reduce insulin levels quickly, prompting your body to switch fuel sources to use ketones. 

Research identifies that intermittent fasting has several other benefits, as it:

If you are looking to improve metabolic flexibility without affecting your lean muscle mass, then intermittent fasting is a well-researched place to start.

5. Get enough rest and repair (stress and sleep management)

The connection between sleep, stress, and metabolic health is a popular topic in clinical research.

Sleep deprivation can lead to chronic health problems such as diabetes or an increased risk of cardiovascular disease. Both the quality and length of sleep are essential to metabolic health.

Even partial sleep deprivation can lead to insulin resistance in an otherwise healthy person. 

In fact, poor sleep can:

  • Affect hormone levels (lowering leptin increasing ghrelin)
  • Increase inflammation in the body
  • Promote insulin resistance
  • Cause chronic health problems
  • Increase weight gain

So, good sleep hygiene is a key part of improving metabolic flexibility. This goes hand in hand with managing stress, which has a very similar impact on your metabolic health.

Stress causes our bodies to release hormones such as adrenaline and cortisol.

When facing a “fight or flight” stress response, our bodies release glucose to provide the extra energy required to deal with the situation. 

Chronic stress causes excess glucose to consistently build up in the body. That built up glucose can lead to long-term conditions like diabetes.

Taking steps to reduce stress and improve sleep reduces extra glucose levels, positively affecting metabolic flexibility. 

Why glucose monitoring is important to metabolic flexibility

Why glucose monitoring is important to metabolic flexibility

As you can see, glucose, metabolic flexibility, and metabolic health are all incredibly closely connected.

You don’t have to have diabetes to have high glucose levels, and high glucose levels cause metabolic dysfunction. 

Being metabolically inflexible drives up glucose levels and holds the body back from switching fuel sources.

To develop a true understanding of your individual metabolic flexibility, you need to monitor your glucose levels. 

How can you monitor your glucose levels?

A CGM is the only way to track glucose in real-time. Glucose monitoring provides biometric data that empowers you to understand what your body needs for the healthiest version of you. 

There is no “one size fits all” approach to achieving metabolic flexibility and optimal health. Every individual has a different genetic makeup and response to external factors. 

Using a CGM to improve metabolic flexibility allows you to:

  • See in real-time how your body responds to food, drink, exercise, sleep, and stress
  • Try experiments to find what works for your body
  • Actively track changes in your glucose levels
  • Make lifestyle changes based on data, not dogma
  • Take control of your metabolic health

How to take control of your metabolic health

Metabolic flexibility is critical in keeping your glucose at healthy levels. 

Without monitoring your glucose levels, you can never truly see the response your body has to any dietary or lifestyle changes you make.

If you want to take a big step towards metabolic health, the NutriSense Continuous Glucose Health Program can provide you with a combination of leading CGM technology and personalized support from Registered Dietitians. The program makes monitoring and understanding glucose simple so that you can take charge of your metabolic health.

Try it for yourself to analyze your glucose levels and meet your health goals. 

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