This Lumen Metabolism Tracker review is not sponsored, but if you are interested in trying it, you may use my affiliate link and the code AHEALTHYSLICE will get your an additional $30 off your purchase.

Have you heard the term metabolic flexibility? Being a health podcast junkie, I’ve heard the term really pick up popularity over the past couple of years. Being metabolically flexible refers to your body’s ability to switch it’s main fuel source between carbohydrates and fat.

Being metabolically flexible can help you achieve better weight maintenance, higher and more steady energy levels, and better blood sugar control, among other benefits.

What is the Lumen Metabolism Tracker?

The Lumen is a handheld, portable device that allows you to track your metabolism in real time. With a breath or two inhaled and exhaled through the device, it can tell you if your body is currently using fat or carbs as fuel. From there, it is able to offer you customized recommendations to optimize your metabolism.

The goal is metabolic flexibility, so knowing this reading and being able to track it throughout the day, before and after meals and workouts, will allow you to focus in on the fuel your body is using. Lumen uses these measurement to guide you in adjusting your habits to teach your body to switch between the two fuel sources.

What is the science behind it?

Lumen helps you to “hack” your metabolism. It does so by measuring your respiratory exchange ratio, which is the ratio between the amount of carbon dioxide produced in metabolism and oxygen used. The Lumen has a flow sensor in the device that measures your oxygen intake/carbon dioxide outflow as you breathe through the device.

When I was a health coach, which feels like a lifetime ago, I offered metabolic testing as part of my services. It was such a great way to kickstart a client’s health journey, as it offered detailed and personalized data. That was 10 years ago, and it’s incredible to me that now power of that information is available in such an accessible way. My testing machine cost thousands of dollars, and now it’s less expensive, handheld, and able to be used daily, instead of every few months.

How to Use the Lumen Metabolism Tracker

One of the things I found most impressive about the Lumen is its ease of use. Initial setup is simple: plug in the Lumen to charge, which takes about 20 minutes. While it charges, download the app to your phone and let it guide you through the simple set up of adding your basic information (age, weight, activity level, etc). Once charged, you’re ready to get started!

The app will guide you through a couple practice breaths, teaching you to inhale and exhale smoothly. It will keep count for you and guide your through an inhale, holding your breath for 10 seconds, then steadily exhaling. Usually you will do this twice, then immediately receive your rating on a scale of 1-5.

1 indicates you are mostly burning fat and 5 indicates that you are mostly burning carbs. The goal is to have your score be a 1-2 in the morning, indicating your body has burned through it’s carbohydrates from the day before and has switched to fat burning mode.

After receiving your morning measurement, Lumen creates a plan for you for the day, including macronutrient goals. This is created by taking into account your fat/carb burning level and your planned workout for the day (it will adjust if you have a heavy workout planned).

Lumen also offers meal suggestions to fit your carbohydrate needs for the day. Their in-app support is wonderful and provides answers to any question you might have (why track macros instead of calories? Should I track all macros or just carbs? Should I track carbs in grams or servings? etc)

*What I have found really interesting and will continue to monitor before I go into it more, is my ability to get into fat burning mode easily changes drastically depending on where I am in my monthly cycle. Is this even a thing? I don’t know, but since Lumen also tracks your cycle and offers recommendations based on where you are in it, it’s been something brought to my attention.

Why is the Lumen helpful?

If you’re into personalized health data, then Lumen is very helpful in teaching you more about how your metabolism works and ways to improve it. Here are some overall pros I’ve found in my use:

• Easy to use device with a quality build
• Good accuracy in measuring your metabolism
• Intuitive app that is easy to navigate and packed with personal data points
• Nutrition guidelines and macronutrient recommendations are helpful, especially if you are new to learning more about how your body reacts to food, workouts, fasting, etc.
• Offers nutrition and exercise recommendations based on where you are in your monthly cycle
• It integrates with Apple Health, Google Fit, and Garmin (I have not used this feature personally but I imagine it might be helpful for those that do!)

How much does the Lumen cost?

Depending on your length of commitment, the cost is between $249-$349. Right now they are having their winter sale, and offering $100 off! If you combine the sale with the code AHEALTHYSLICE, you will receive an additional $30 off if you purchase before January 31, 2022.

Is a Lumen Worth the Cost?

That’s a personal choice. If you are someone that has struggled with weight management, someone who enjoys learning about how their body can function more optimally, or just nerds out on personal health data, Lumen could be a great fit for you!

Personally, I find the device fascinating and will continue to use it. I am working on remembering to take measurements more often throughout the day (before and after workouts especially) so I can get more clarity on how my body functions throughout the day, as well as improve my Flex Score.

What is a Lumen Flex Score?

After 4-8 weeks of data, Lumen provides you with a flex score, showing you how flexible your metabolism is. The measurement is a comprehensive evaluation of your metabolism initially based on 4-8 weeks of measurements and other tracked metabolic factors to determine your flexibility.

My first flex score was a 13 (on a scale from 1-21). While I was initially disappointed, I now see it as exciting because I have room for improvement! (After the holidays, I definitely have some room for improvement…)

While I don’t typically count macros, I am going to attempt to abide by the carbohydrate recommendations for a couple weeks to see how it makes me feel. As someone with a history of insulin resistance, this is the most intriguing benefit for me.

If you have any other questions about this device, please ask; I’m happy to answer! I’ll also be sharing a video on IG today of a breath measurement so you can get a better idea of how it works.