Lumen Review: Did The Metabolism Tracker Help With My Weight Loss?

As a registered nurse who's struggled with weight loss and weight maintenance, I've always felt a little in the dark about what is actually going on in with my metabolism day-to-day.

That's why I was eager to test out the Lumen Metabolism Tracker, a portable device that's like a breathalyzer for your metabolic health. The Lumen analyzes your breath's CO2 levels to determine how your body is fueling itself (through burning fat or burning carbs).

Not sure why that matters? For starters, you don't lose excess weight if you're never in fat-burning mode—and the Lumen helps you determine what personalized dietary and lifestyle changes you can make to get there.

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.

Lumen is a handheld device that gives you real-time insight into how your metabolism is functioning. There are two parts: the breathalyzer and the device's corresponding app.

I found the system incredible easy to use. You simply follow the prompt on the app to get your reading: inhale for 10 seconds, hold your breath for 10 seconds, and then slowly exhale for 10 seconds. How's that for breathwork?

The brand recommends taking the breath measurement each morning. After each reading, the app update its recommended nutrition plan and macro count.

Added features on the app include a brief daily video with helpful tips for metabolic health, as well as a brand 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.

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. 

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 formatted it into an at-home device.

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. 

People often ask if Lumen is the same as following a ketogenic lifestyle—and the short answer is no.

After testing the Lumen metabolism tracker for six months, I believe it's a great (noninvasive!) tool for just about anyone. Whether your goal is to lose weight or to optimize your workout results, the Lumen can help shed light on what's going on in your body.

During the first few weeks of testing the Lumen metabolism tracker, I was waking up in carb-burning mode only. This means 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. Ergo, the way I was eating would never allow me to lose weight.

Based on these insights, the Lumen app recommended I eat a lower-carbohydrate diet each day and increase my protein and fat intake.

For me, simply lowering and tracking my carbohydrates was enough 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 using the device (and, of course, continue making changes to my diet and lifestyle as needed).

In my experience, the science behind Lumen's personalized recommendations really did work. I could see firsthand how each meal affected my metabolism.

Six months later, I truly feel as though I've found a product to take me away from fad or restrictive diets. Instead, the Lumen helps me focus on my own personalized plan to optimize my metabolic health.

If you are someone who thrives on personalized insights and tracking small wins (rather than the number on a scale!), I recommend trying Lumen. 

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. Only the first-morning measurement is required for Lumen to create your personalized nutrition plan, but I've found multiple measurements throughout the day really enhance your learnings.

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.

RELATED: The Best Metabolism Trackers Of 2023, From An RN

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.

At the end of the day, I believe Lumen is 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. 

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. 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.