Disclaimer: None of the information in this article constitutes medical advice. All statements are merely the opinion of the writer(s). We recommend that patients follow their doctor’s guidance in regard to metabolism and weight loss.

Lumen is a tech company with a bold claim: that a breathing device can help you "see lasting weight loss." The product has been featured in major publications like Entrepreneur and TechCrunch.

But is Lumen proven to work? What is "metabolic flexibility," and how does it affect weight loss and overall health? What are our concerns about some of the health claims on the Lumen website? And is Lumen better or worse than popular weight loss devices like VibroSculpt?

In this article we’ll answer all of these questions and more, as we analyze clinical trials on metabolic flexibility, and share our thoughts about whether or not Lumen likely to be effective for weight loss.

We'll also highlight some questionable health claims on the brand's website, and compare Lumen to other popular weight loss devices to pick our winners (and losers).

Key takeaways:

• Concept behind Lumen makes sense theoretically
• Proven effective in pre-diabetics
• We do not currently recommend Lumen for non-diabetics

Does Lumen Cause Weight Loss? 

Lumen’s value proposition centers on a concept called "metabolic flexibility," which refers to the body’s ability to shift between burning fat or carbs as a primary energy source.

Metabolic flexibility is a legitimate medical theory.

A medical review published in the Cell Metabolism journal analyzed how metabolic flexibility is associated with health and disease.

The study authors described how metabolic inflexibility may contribute to poor health.

Insulin resistance occurs when the body’s metabolism of carbohydrates breaks down and becomes less efficient due to beta cell dysfunction.

A healthy person has no issue switching between fat or carbs as a source of energy, but an unhealthy person may struggle with either or both.

A 2018 medical review explored the topic of metabolic flexibility in more detail, explaining many factors that influence it. Gastrointestinal peptide release, natural hormone production and mitochondrial function were all listed as factors that can affect metabolic flexibility.

The second review is more interesting than the first, because it also outlines research-backed ways to improve metabolic flexibility. Lifestyle interventions are effective for countering metabolic inflexibility, according to the researchers.

Exercise (both aerobic and anaerobic), normalization of weight for overweight and obese individuals, interruption of sedentary behavior like short walks during work, and supplementation of certain amino acids like l-carnitine were all suggested to improve metabolic flexibility in the above-linked medical review.

While the general concept behind Lumen is legitimate, we cannot identify any clinical research suggesting that Lumen optimizes metabolic flexibility in healthy individuals beyond the healthy lifestyle changes described above.

Basically, the standard healthy lifestyle recommendations most people are used to hearing seem to be the biggest factors in enhancing metabolic flexibility: eating healthy, exercising, and avoiding a sedentary lifestyle.

Lumen claims to measure carbon dioxide levels in the breath to determine a “flex score” that shows consumers how flexible their metabolism is. It’s important to note that neither medical review we examined mentioned carbon dioxide levels at all.

In our opinion, whether or not Lumen can effectively track various indirect measures of metabolism doesn't matter, because it's illogical to pursue weight loss based on those measures.

We do not currently recommend Lumen for weight loss in non-diabetics, because we're unable to identify any clinical studies showing it causes weight loss in otherwise healthy individuals.

Is Lumen Better for Diabetics?

Lumen is clinically shown to accurately measure whether carbs or fats are being used as a source of fuel, although we're unsure of the usefulness of that information.

More importantly, Lumen was shown to support optimal metabolic function and cause weight loss in adults with pre-diabetes in a 2023 clinical trial.

This suggests that individuals with pre-diabetes or diabetes may benefit from speaking with their doctor about Lumen.

It's unclear whether it's the device itself or the personalized nutrition planning that caused the weight loss, but this is an impressive result given that this program seems to have little if any risk.

We consider Lumen's value proposition to be much greater for individuals with blood sugar dysregulation than for individuals with healthy blood sugar levels, in light of the current state of the data.

Lumen vs. Popular Weight Loss Devices

Here's how Lumen compares to other popular weight loss devices in terms of potential efficacy and safety, in our opinion:

VibroSculpt

Although commercial vibration plate machines are clinically shown to cause fat loss, we cannot identify any evidence that vibration gun machines like the VibroSculpt do.

This brand makes questionable and uncited medical claims on their website, and we consider the device unlikely to have any functional effects.

Lumen is the winner from a potential efficacy standpoint.

Winner: Lumen

Infinity Hoop

Weighted hula hooping is clinically shown to cause weight loss, as we documented in our Infinity Hoop reviews article.

We consider this product likely to support weight loss in all overweight individuals, whereas we only consider Lumen likely to support weight loss in pre-diabetic and diabetic individuals.

Infinity Hoop is the winner from a potential efficacy perspective.

Winner: Infinity Hoop

Plenity

This is a pill which is classified as a "medical device," because it's non-nutritive and has a physical mechanism of action (it takes up space in the stomach to make users feel full faster).

At the time of our most recent analysis, we were unable to identify any clinical research showing that the unique Plenity formulation is effective for weight loss.

These pills also have two ingredients we consider potentially unhealthy.

Lumen is the winner from a potential efficacy and safety standpoint.

Winner: Lumen

Our Healthy Body Weight Picks

Ceylon cinnamon was shown to support healthy body weight in a 2022 meta-analysis. The study authors concluded that effects were greater at doses at or over 3 grams daily.

Illuminate Labs Ceylon Cinnamon Extract is our standardized Ceylon cinnamon supplement which is third-party tested to ensure purity and potency.

Dietary fiber was shown in a medical review published in The Journal of Nutrition to help reduce body weight when combined with moderate caloric restriction (750 calories per day below baseline).

MBG Organic Fiber Potency+ is our top fiber pick because it's certified organic, provides 7 g of fiber per serving and costs under $1.85 per serving at the time of updating this article.

Both of the products mentioned in this section are free of ingredients that we consider to be unhealthy.

These statements have not been evaluated by the FDA. These products are not intended to diagnose, treat, cure, or prevent any disease.

Lumen Pros and Cons

Pros:

• Clinically shown to accurately track data
• Clinically shown to support metabolic health in adults with prediabetes
• Clinically shown to cause weight loss in adults with prediabetes
• Non-invasive
• Unlikely to cause side effects or harm
  
• Company's general claims about metabolic inflexibility are accurate
• Healthier than some competitors

Cons:

• We can't find any clinical evidence this device causes weight loss in adults without pre-diabetes
  

Conclusion

We do not currently recommend Lumen in individuals without blood sugar issues, because we're unable to find any evidence of efficacy in that group.

Lumen was shown to improve metabolic function in adults with pre-diabetes, so for that patient population, we recommend speaking with your doctor about whether or not the device may be worthwhile.

We commend Lumen for continuing to fund clinical research published in peer-reviewed medical journals, which is a sign of a high-quality brand, and which is the gold standard for health product research.

Metabolic inflexibility appears to be associated with dysregulation of metabolism and overall health, and there are free lifestyle changes that health-conscious individuals can make such as increasing exercise and normalizing weight (for those who are overweight or obese).

One benefit of Lumen is that it's a physical device which is non-invasive, and is therefore unlikely to pose any health risks or cause side effects.

We haven't come across any convincing clinical evidence that it matters whether healthy individuals follow a low-carb or a high-carb diet. 

We consider Lumen to be a better weight loss option than VibroSculpt and Plenity, but a worse option than Infinity Hoop (though these products are not necessarily mutually exclusive).