Free Discovery Call

How to Improve Metabolic Flexibility with Lumen

Jan 30, 2022

This episode explains how to improve your metabolic flexibility using Lumen. Lumen is a small, convenient breath device that helps your body develop metabolic flexibility. That means you can efficiently switch between using carbs and fat for fuel. 

 

How Does Lumen Measure Fat Burning?

Lumen identifies if you’re using carbs or fats for fuel by measuring the level of carbon dioxide in your breath. When your body's cells produce energy from either carbs or fats they release carbon dioxide into your bloodstream. 

When you're using carbs for fuel, more carbon dioxide is released than when you're using fat. This translates into carbon dioxide levels in your breath which Lumen measures. Pretty cool. A higher level of carbon dioxide means your body is using carbs. A lower level of carbon dioxide means your body is using more fats. 

To get the most out of Lumen, you're going to want to use it each morning at the very least, and follow its personalized macronutrient plan each day. What your body uses for fuel in the morning is a main indicator of your metabolic health. 

Lumen has 5 levels. Level 1 means you’re burning mostly fat for energy, while level 5 means you’re using carbs for energy. Ideally, a good goal to have a Level 1 or 2 when you wake up in the morning. That means your body is burning fat overnight. Using a lower-carb approach and intermittent fasting are two excellent tools to help you get into a fat burning mode. 

If your body is using carbs for fuel right when you wake up, several things could be going on. You may have eaten later at night, eaten too many carbs the day before, been stressed out, or have had a bad night of sleep. In my case, sometimes I overdo it on the protein, which can be turned into glucose and hamper my fat burning ability. So seeing that higher lumen level in the morning is a good reminder to check-in with yourself and see where you can optimize for fat burning.

If you are constantly eating carbs throughout the day, your body won’t have a chance to utilize the glucose in your blood, and glycogen in your liver and muscles to truly tap into excess fat storage for energy. 

As a friendly reminder you can become metabolically inflexible the other way, too. If you're eating very low carbohydrate for a sustained amount of time, your body reduces its ability to efficiently process carbohydrates. This is when I get reports of people who have gone keto have such a strong rebound of weight gain when they don’t sustain that diet and start eating carbohydrates again.

Lumen also likes to keep track of things like your daily exercise, sleep, and carbohydrates. Based on this information it gives you customized macronutrient goals for the day to improve your metabolic flexibility. 

Lumen’s Metabolic Flexibility Score

What's interesting about Lumen is that it provides a metabolic flexibility score which is measured on a scale of 0 to 21. A great metabolism is flexible. It's good at shifting quickly between fuel sources based on its needs. 

To estimate how healthy and flexible your metabolism is, Lumen relies on three factors. Your body's ability to burn fat. Your body's ability to burn carbs. And how closely your morning flex score is in sync with your daily lifestyle data that you’re entering. 

Levels 0 - 6 means your metabolism is not as flexible as it could be. 7 to 14 means your metabolism is healthy. And 15 to 21 means your metabolism is very flexible. 

To teach your body to use both sources of fuel, Lumen recommends a customized nutrition plan each day. What this means is that it gives you slightly different macronutrients goals for the day. 

It also gives you high carb days which they call Boost days to help your body shift to burning carbohydrates. The ratio between the low carb and the high carb days will depend on your personal metabolism and goals. 

Benefits of Having a Flexible Metabolism

There are a lot of benefits to having a flexible metabolism. Your blood glucose levels will be more consistent so you'll have more energy throughout the day with less energy crashes. 

You'll perform better during workouts and have fewer carb and sugar cravings. Your insulin sensitivity will improve which will help your body burn fat more effectively, build lean muscle mass, and improve your body composition more easily. As your insulin sensitivity improves, your insulin resistance goes down, which is what I’m all about for sustainable weight loss and disease prevention. 

A strong level of metabolic flexibility has also been linked with a stronger immune system and better sleep quality. One of my new members spoke truth into this as just a month into her lower carb, intermittent fasting lifestyle - and mind you she wasn’t doing anything more than about 13 hours of fasting each day, reported better sleep quality, better fitting jeans, a thinner face, and less PMS symptoms - in just one month. 

Research has shown that people who are more metabolically flexible are less likely to develop chronic health issues like obesity, diabetes, and heart disease. Again this goes back to reducing insulin resistance. 

Lumen’s Personalized Nutrition Plan

Based on my own research, Lumen’s nutrition plan (or daily macronutrient ratios) lined up with what I typically recommend to my members so I was happy to see that. The amount of protein remained pretty steady each day while the amount of carbohydrates and fats is what fluctuated. 

To make it easier to follow their nutritional recommendations they've included some tools inside their app and highly encouraged you to focus first on carbohydrates. I liked this because when you’re just starting out, it may be overwhelming to try and focus on optimizing all your macros. Prioritizing reducing carbs is a good call. 

There are a few basic trainings in the form of click through images and short videos - sort of like instagram content - explaining how to use Lumen and get the most out of it. They also provide some resources to track your carbohydrate servings in a day. They have a food database which will give you the food and how many carb points it is for the day. Lumen also has some nice recipes for meal inspiration. They are planning on rolling out an in-app food tracking system so that you don't have to use a separate app like the Carb Manager App I like using.

Personally I think it's a lot simpler to just track net carbohydrates instead of trying to learn their rules for how many carbohydrate points certain carbohydrate foods have. And you can absolutely do that, too. 

They just use the points system to try to make it simple for people who don't want to track their macronutrients. However from my experience I know that carbohydrates, specifically added sugar, are hiding in a lot of “healthy” foods. To get the most out of Lumen I do recommend that you also track your macronutrients.

It will be highly beneficial when they have their own macronutrient tracking system inside of their app, a feature that should be rolling out very soon. I'm interested to see if the daily macronutrient goals change according to their recommendations based on your breaths. 

The Carb Manager macronutrient goals are the same every single day, which makes getting the most from Lumen a little difficult, and why I think they emphasize focusing on tracking carbs first to make it simpler. My guess is that in the Lumen tracking app your macronutrient goals will be automatically updated each day to help you reach your metabolic flexibility goals.

Who Might Benefit the Most from Lumen?

Personally I think that the Lumen device would be most beneficial for athletes who want greater insight into how to optimize their performance during workouts. You can take a breath before your workout to understand if you're using carbohydrates or fat for fuel before your workout. 

Carbohydrates are the preferred fuel source for high-intensity workouts because they're very efficient for your body to use when it needs quick energy. 

If you don't have enough available energy before a high intensity workout you may feel sluggish and light headed, so the Lumen goal before a high intensity workout would be to achieve at 3, 4, or 5, indicating you’re using some or mostly carbs. 

If you're at a level one or two (meaning you're using mostly fat) a small dose of carbohydrates before your high intensity workout may help improve your performance. For a low intensity workout such as a walk or yoga, you'll be just fine using fat for fuel. 

 

What is a Lumen Boost Day?

The last thing I wanted to talk about was what Lumen calls a Boost day. When you're practicing a low-carb diet for a long time, you're risking your body's ability to use carbs as fuel efficiently. This means when you do eat carbs, you’re going to feel bloated and gain weight quickly. 

On your Boost day you'll be eating significantly more carbohydrates than your baseline, but they do recommend getting them from whole food carbohydrate sources such as fruit, veggies, or grains. It's important on your Boost today to take a breath measurement 30 minutes after eating your high-carbohydrate meal. Getting a 3, 4, or 5 will show that your body has shifted to use carbs for energy and that your Boost day worked. 

This information is worked into your overall metabolic flexibility score which you can get after having a couple weeks of data. That’s why regular breath measuring and following their nutrition plan is important for accurate results. 

In Zivli we teach exception days. We recommend following your baseline plan about 90% of the time when you're losing weight and 10% of the time having an exception day. Everyone's exception day will look different based on their personal goals, nutrition preferences, and mindset around how loose they want to get with their nutrition. 

Measuring Fat Burning with Ketones Versus Carbon Dioxide

My overall assessment of Lumen is that it's a lot like anything else in life. You're going to get out of it what you put into it. I found it interesting that Lumen measured fat burning via carbon dioxide levels, whereas I was used to measuring my ketones to assess my level of fat burning. 

Ketones are a byproduct of fat metabolism so they are a really accurate way to assess if your body is burning fat for fuel. I did notice the Lumen tended to be easier to manipulate. If you take a test breath too close together you're going to get false data that you're leaning more into fat for fuel. 

So, definitely take several relaxing minutes between breaths if you're going to be doing repeat testing to get more accurate information.

I did appreciate that the Lumen was easy and convenient to use and that I didn't have to prick my finger or get a ketone test strip out to check if I was in a fat burning mode or not. 

I believe that this would be best utilized by someone who already is comfortable tracking their macronutrients and is ready to optimize their metabolic flexibility. If you want to start tracking your macros we have free trainings for you here. I would also love to use this device during a longer fast to measure how my metabolism was changing throughout the fast.

Because I am so evidence-based, I did appreciate that they tried to make the evidence behind how to achieve a flexible metabolism as simple as possible. Lumen tells you what to do. However, if I was a newbie I would probably need a little bit more information for how and why to do things. They do have a Facebook group that likely offers some level of support. They also have nutritionists customer support to help Lumen users get the most out of their experience. 

Knowing what to do works well for some people, for other people they need a little bit more support and accountability to learn how to do it consistently. Our goal with Zivli is to give you what to do, how to do it, why to do it, and the ongoing coaching and behavioral support so that you do what you know you need to do consistently. 

How to Get Lumen

If you're highly motivated, detail-oriented, love learning, and you want to take your results to the next level, give Lumen a try. I'll put a link in the description below this episode for how you can try Lumen yourself. You can learn more on their website here. The code DRNOLTE40 gives $40 off for the first 100 people who use it! This episode was sponsored by Lumen.

 

Listen to This Episode

 

Download My Free Weight Loss Masterclass

This free 55-minute training explains why insulin resistance and inflammation are at the heart of weight gain ... and how to fix them!