Skip to content

A Deep Dive On The Lumen Metabolism Tracker & How It's Changed My Health, From An RN

Amanda Lundberg, RN
Author: Medical reviewer:
Updated on August 21, 2023
Amanda Lundberg, RN
Registered Nurse (RN)
By Amanda Lundberg, RN
Registered Nurse (RN)
Amanda is a registered nurse with over a decade of experience in clinical nursing and a member of the Association of Healthcare Journalists.
Scott Nass, M.D., MPA, FAAFP, AAHIVS
Medical review by
Scott Nass, M.D., MPA, FAAFP, AAHIVS
Board-certified Family Physician
Scott Nass, M.D., MPA, FAAFP, AAHIVS is a family physician and HIV specialist in California. He takes a holistic approach to healthcare, incorporating principles of functional medicine and using food as medicine when working with patients.
Lumen Metabolism Tracker
Image by mbg creative
August 21, 2023
We carefully vet all products and services featured on mindbodygreen using our commerce guidelines. Our selections are never influenced by the commissions earned from our links.

If you've ever struggled with weight loss or maintenance, you may have already done a lot of research on how to optimize your metabolic health (and perhaps to no avail).

As a registered nurse who's been in those shoes herself, I've dug deep into the best metabolism trackers and made the informed decision to invest in a Lumen Metabolism Tracker.

After all, even successful athletes have sworn by this device's ability to provide life-changing feedback. Below, I'm sharing my honest Lumen review, including tips and tricks on how to integrate it into your own life.

Lumen Metabolism Tracker

Lumen Metabolism Tracker

What is metabolism?

Your metabolism is a complex series of processes in the body that help transform food into energy and waste. This essential reaction supplies our bodies with the energy it needs for vital functions, such as cell growth and other bodily processes.

Metabolism affects our bodily functions in a variety of ways, including how quickly and efficiently we are able to burn calories and convert carbohydrates, proteins, and fats into energy. 

Poor metabolism can lead to a number of health conditions, such as obesity, diabetes, and high cholesterol levels. People with higher metabolism rates tend to have more optimal overall health than those with lower metabolism rates, due to improved efficiency in burning off excess fat. As such, boosting your metabolic health can greatly improve your overall health and well-being.

What is the Lumen metabolism tracker?

Lumen is a handheld device that gives you real-time insight into how your metabolism is functioning. There are two parts: the brand's app and its device. The sleek and compact Breathalyzer device fits in your palm and is charged using a micro-USB.

It's incredibly easy to use, with prompts on the app that will tell you to inhale for 10 seconds, hold your breath for 10 seconds, and then exhale slowly for 10 seconds. Your results will instantly be viewable within the app, with real-time insights on your current metabolic state. 

The comprehensive app houses your breath measurements from the device, along with a food diary and an option to track your weight, exercise, and macros. The brand recommends taking the breath measurement each morning, at which time the app is updated to display a recommended daily nutrition plan, including macro counts.

Added features on the app include a brief daily video with helpful tips, as well as a direct connection to the brand's support chat.

When used regularly and correctly, Lumen enables you to understand the impact of key lifestyle factors (such as nutrition, sleep, and stress) on your body. The device and its recommendations are science-based, and the app acts as an insightful, personalized health coach, guiding you to make healthier choices to improve your metabolic health.


The Lumen is a handheld device that provides unlimited real-time metabolic measurements.

How much does Lumen cost?

Lumen's pricing plan is dependent on an active membership, which includes the device, access to the Lumen app with real-time insights into your metabolism and data about your metabolism health, a personalized daily nutrition plan, and daily video coaching.

The Lumen device is not meant to be shared (unless you opt for the duo subscription), as the device is linked to your personal account and is meant to learn your habits over time. 

There are three subscription options available:

  • 6-month subscription for $249
  • 12-month subscription for $299
  • 12-month duo subscription (one device shared by two users) for $479
Lumen Metabolism Tracker
Image by mbg creative

How it works

Lumen uses patented algorithms, CO2 sensors, flow meters, barometric pressure, and temperature-sensing technology to determine the carbon dioxide concentration in a single breath.

While this is not new technology, the mode of testing CO2 is usually a lengthy, cumbersome process requiring a trip to a medical facility. Lumen has taken this technology and designed an at-home device, giving anyone access to real-time metabolism insight. 

The concentration of CO2 in your breath indicates the type of fuel your body is using for energy: carbohydrates or fats. After each breath measurement, Lumen calculates a metric (the "Lumen level") on a scale of one to five (one indicating fat is being used to fuel your body and five meaning carbohydrates are being used).

It's important to understand that your metabolism is a flexible process, which either uses fats or carbohydrates to convert to energy. If your body has excess carbohydrates, it will use these first since they are more easily converted to energy.

Alternatively, if your body has little stores of carbohydrates, it will switch to using excess fats to convert to energy. The ideal scenario? Your body begins in fat-burning mode first thing in the morning before shifting to burning carbohydrates throughout the day and eventually going back into fat-burning mode before bedtime. 

The Lumen device makes it easy to determine whether you are eating too few or too many carbohydrates, plus how the timing of your meals affects your metabolism. This data allows users to adjust their diet and movement patterns to align with their metabolic goals. 

Lumen Metabolism Tracker
Image by mbg creative

Is Lumen the same thing as following a keto lifestyle?

People often ask if Lumen is the same as following a ketogenic lifestyle—and the short answer is no. Lumen's nutrition plan is not based on a ketogenic diet but instead focuses on metabolic flexibility by recommending varying days of low, medium, and high carbohydrate intake. 

Who should try Lumen?

Lumen is a noninvasive product recommended for just about anyone, whether you're looking to lose weight or hoping to optimize your athletic training. That said, Lumen is not suitable for anyone who is:

  • Under the age of 16
  • Women who are pregnant or exclusively breastfeeding
  • Has a history of eating disorders
  • Has diabetes
  • Has severe asthma
  • Has Chronic obstructive pulmonary disease (COPD)
Lumen Metabolism Tracker
Image by mbg creative

Getting started with Lumen

The Lumen box is akin to a work of art. Its sleek and modern packaging illustrates the quality of the device, and the handheld Breathalyzer comes with a neoprene carrying case and a charging cord.

Once you receive your package, the first step is to download the Lumen app and begin your journey by inputting your current health goals, weight, and lifestyle habits. 

A feature I found most helpful was the weekly live onboarding webinar. This supportive presentation goes in depth on how to use Lumen and ends with a friendly Q&A. It's recommended that any new user attend this webinar to gain a better grasp of the product and its comprehensive features. 

Lumen Metabolism Tracker
Image by mbg creative

My experience with Lumen

During the first few weeks of using Lumen, I was waking up in carb-burning mode only, meaning I had extra stores of carbohydrates from dinner (or perhaps from those Girl Scout cookies). In other words: My body was never in fat-burning mode, which meant the way I was eating would never allow me to lose weight.

Lumen recommended eating a lower-carbohydrate diet each day and increasing protein and fat macros. For me, it was just enough to track my carbohydrates to eventually see a shift in my metabolism.

After a few weeks of tweaking my diet, I finally woke up in fat-burning mode. This positive reinforcement from Lumen was the drive I needed to continue altering my diet. If you are someone who thrives on little wins rather than the number on a scale, I recommend trying Lumen. 

In my experience, the science behind Lumen worked, and I could see firsthand how each meal affected my metabolism. I truly feel as though I've found a product to take me away from fad or restrictive diets, and instead toward focusing on my personalized plan to optimize my metabolic health.

I plan to continue using the device and its recommendations—and I'm learning more each day about how to "hack" my metabolism and improve my overall health.

Lumen Metabolism Tracker

Lumen Metabolism Tracker

Is Lumen worth it?

Lumen is worth it if you plan to use it regularly and are committed to learning about your metabolic health (and open to making the changes it suggests). 

While, yes, the device is easy to use and the results are displayed instantly, it does require a time commitment to take multiple measurements throughout the day. Although only the first-morning measurement is required for Lumen to create your personalized nutrition plan, multiple measurements throughout the day will further enhance your learning. There are many other times when it makes sense to take a measurement, including before and after workouts, before and after each meal, after fasting, and before bedtime. Again, the measurement itself takes less than a minute, but it's something to be mindful of when considering the purchase.

If you have ever kept a food diary, you know it can be time-consuming to measure portion sizes, read labels, and so on. Additionally, you'll want to consider the learning curve of exploring how different foods, exercise, meal times, sleep, stress, and menstrual cycle affect your metabolism—it's truly an endless process. With that in mind, many reviewers say the process becomes effortless after a few months, as you gain more of an understanding of your body. 

At the end of the day, the science behind Lumen makes it worth it. Testing your CO2 levels to find out whether your body is using fat or carbohydrates for energy is a tried-and-true method—but Lumen is so much more than just a breath test. The integrated app offers a way for users to alter factors that affect their metabolism. What you eat, when you eat, how long to fast, when to exercise, and even your sleep habits are all factors to keep in mind when learning how your body processes energy. 

Given the amount of time it takes to explore all that the device and the app have to offer, it makes sense that Lumen's shortest subscription available is six months long. To make the most of your time with Lumen, I strongly suggest taking advantage of the live onboarding webinar and the brand's responsive live chat, which is available 24 hours a day.

Frequently Asked Questions

Can you use Lumen without a subscription?

Lumen will only work with a subscription. The brand offers six- or 12-month subscriptions, which renew automatically if not canceled. 

How long after eating should I use my Lumen?

You should wait one to two hours after eating to see a shift in your metabolism. Although not required, the more daily measurements you take, the more comprehensive and impactful your results will be.

Does Lumen help you lose weight?

Lumen helps users learn if they are using fats or carbohydrates to convert to energy. To lose weight, your body needs to fluctuate fluidly from fat-burning to carbohydrate-burning. Using the Lumen device alone will not make you lose weight, but it will help guide you to making healthier food choices personalized to your body and your metabolism, which can lead to weight loss. 

How quickly does Lumen work?

Lumen provides an instant assessment of your current metabolism, but it takes at least two weeks of continued use for Lumen to calculate a flex score. This score represents how flexible your metabolism is.

Is Lumen FDA approved?

Lumen is currently not FDA approved, nor is it considered a medical device. Lumen should be used to provide individuals with personalized nutritional guidance; it should not be used to diagnose or treat medical conditions. We recommend discussing your results with your health care provider.

Is Lumen evidence-based?

Yes: In 2021 the brand worked with San Francisco State University on a peer-reviewed validation study that compared results from the Lumen device with those from a TrueOne 2400 metabolic cart (ParvoMedics). The study found that the CO2 levels obtained with the Lumen device matched the values from the metabolic cart. 

Lumen Metabolism Tracker

Lumen Metabolism Tracker

The takeaway

As a nurse and a woman who has struggled with weight loss and a slow metabolism her whole adult life, trying Lumen was eye-opening and validating. Lumen is an excellent product for anyone who wants to take control of their metabolism.

Combining modern technology with time-tested nutrition science, it provides a unique approach to understanding and managing your bodily functions. Of course, as with any lifestyle change, making a habit in a short amount of time can be tricky.

However, with patience and dedication to Lumen, the rewards can greatly impact your health.

Amanda Lundberg, RN author page.
Amanda Lundberg, RN
Registered Nurse (RN)

Amanda is a registered nurse with over a decade of experience in clinical nursing. Her passion for wellness and preventative care led her to focus on collaborating with patients to manage disease processes. Aiming at continuing active lifestyles for her patients, Amanda has become an expert in adjunct therapies. Now she's taken her medical experience and passion for articulating technical medical language into a freelance writing career. This includes writing health and well-being content for brands, as well as clinically reviewing articles for medical accuracy.