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 “hack your metabolism” to increase fat loss, lose weight, and boost energy naturally.
In this article we’ll review whether there is any medical research proving Lumen to be effective for weight loss, and share our thoughts on whether metabolism tracking is necessary or beneficial for weight loss. We'll critically assess some health claims made by Lumen that we find to be questionable.
Does Lumen Work?
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 concept. A medical review published in the Cell Metabolism journal in 2017 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 more recent 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 which can determine 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 scientists.
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 are all suggested to improve metabolic flexibility based on research.
While the general concept behind Lumen is legitimate, we cannot identify any medical research suggesting that Lumen improves health or weight loss beyond standard lifestyle changes.
Basically, the standard healthy lifestyle recommendations most people are used to hearing seem to be the biggest factors in enhancing metabolic flexibility.
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 believe Lumen is likely to be effective at tracking what the company claims it can track, but what's the point of doing so if it cannot improve health beyond making healthy lifestyle changes like eating whole foods and exercising?
Questionable Health Claims
Lumen makes many uncited health claims on their website that we find to be extremely questionable.
Lumen did publish a medical trial proving that their device can accurately measure whether carbs or fats are being used as a source of fuel, but there doesn’t appear to be any evidence that this information can help optimize metabolic flexibility beyond the basic recommendations we’ve already covered.
Why does it matter whether a person is burning fat or carbs for fuel if they’re healthy? The entire premise behind the company is confusing to us.
Lumen makes bold claims about the general health benefits of metabolic flexibility, but doesn’t explain how their device helps achieve that. Under a “How can we improve metabolic flexibility” header, Lumen gives generic advice like “Exercise” – that’s good advice, but why pay for a hardware device telling you to exercise?
We also disagree with the company's claims of enhanced fat burn and weight loss, because there appear to be no medical studies proving that Lumen causes weight loss.
If someone buys a phone app that buzzes to tell them to go for a run, the phone app doesn’t “melt away fat,” the fact that they went for a run does. Lumen is the phone app in this analogy; a device that may suggest healthy practices, but doesn’t directly cause any physical changes, so we consider it to be a waste of money and disagree with the health claims made by the brand.
Dietitian Explains Whether Lumen is Legit or Not
One of the most popular YouTube reviews of Lumen is published by a channel called "Abbey Sharp." The creator is a Registered Dietitian (RD) and gives her take on whether or not Lumen is legit. It's a well-researched video in our opinion, and appears unsponsored:
Lumen Real User Review
A YouTube channel called "Fitness & Finance" published a review on Lumen that appears to be unsponsored. The creator used the device for three months and shares his honest opinion on it:
Our Weight Loss Supplement Recommendations
There exist several weight loss supplements with significant clinical backing in terms of both efficacy and safety.
We recommend dietary fiber as a safe and effective weight loss supplement, especially when combined with caloric restriction.
A landmark medical study found that moderate caloric restriction (750 calories per day below baseline) combined with dietary fiber intake (a minimum of 20 grams per day) caused an average weight loss of 16.03 pounds over 6 months. That’s a pace of 32 pounds per year of weight loss in overweight individuals simply by adding fiber to a moderately-restricted-calorie diet.
The fiber supplement we recommend is SuperGut Fiber Mix. It contains a clean and effective formulation: a blend of three different types of unflavored dietary fiber and zero additive ingredients. It can be mixed into liquids or foods. Interested consumers can buy SuperGut fiber at this link.
We recommend using two fiber mixes per day, which provides 16 grams (g) of total fiber. Diet should provide the remaining fiber necessary to meet the 20 g minimum threshold.
Medium-chain triglyceride (MCT) oil is another dietary supplement which has been shown in clinical trials to cause weight loss.
MCT oil is quickly absorbed by the body and increases metabolic rate, which causes fat loss. A meta-study on MCT oil documented weight loss of 1.12 pounds over 10 weeks. This equates to a potential annualized weight loss of 5.84 pounds with MCT oil supplementation.
We recommend Bulletproof MCT Oil as our top MCT oil product, because it has a clean and effective formulation. The only ingredient is MCT oil derived from coconuts, and the product has no questionable additives. Interested consumers can buy Bulletproof MCT Oil at this link.
The effective dose range of MCT oil for weight loss (based on the medical review) is 1.7 g to 10 g per day. Bulletproof's MCT oil provides 14 g in one tablespoon, so around two-thirds of one tablespoon should be a maximally-effective dosage.
