Metabolism Hack: Nutrition Breathalyzer Tells You What to Eat

Breathe into the Lumen personal wellness device, and AI will tell you what to eat to optimize your health.


At least, that’s the claim by its maker, Lumen. A team of scientists, engineers, and designers runs the emerging digital health and wellness company.

The Lumen handheld wellness device, now available on Indiegogo, looks like a fat vape pen. But instead of breathing in to get high, you breathe out to measure your health status.

The smart pocket wellness tool syncs with a free iOS or Android app. When you huff into the breathalyzer-like device, the AI inside instantly analyzes the gases in your breath.

A partner mobile application then translates that metabolic data into guidance on what to eat for your specific metabolism.

Beta testers have tried the Lumen handheld, which fits into a pocket, to shed some unwanted pounds and maximize athletic performance. Lumen said it has already helped more than 300 people lose an average of 6.8 pounds in one month since testing started last year.

Some described using the Lumen each morning instead of a scale.

How Lumen Looks at Health and Fitness Data

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Lumen measures daily carbohydrate and fat intake. The right ratio of these two key energy sources fuels the body and can also keep it at an ideal weight. Elite athletes already use this equation to hit peak performance when training and racing.

handheld wellness device
Elite athletes typically have modified metabolisms that burn fuel more efficiently.

But Lumen is for the masses. Here’s how it works.

When you puff into the Lumen device, AI technology reads respiratory exchange ratio (RER), a measure of metabolic fuel. Your CO2 production and O2 uptake supposedly show how much energy you’re burning from carbohydrates versus fat.

Higher CO2 levels in your breath signal that you’re burning more carbs; lower CO2 in your breath means you’re burning more fat. For weight loss, the latter is preferable. The brand said it has conducted numerous studies to validate the methodology.

From there, the real-time physiological data feeds into an accompanying app, which spits outs tailored nutrition guidance on your phone. Digital food plans are based on your exhaled air and what the app has learned about your body.

How to Use the Lumen Device for Daily Health Advice


Each morning, wake up and breathe into the device. The Lumen essentially processes how yesterday’s meals, sleep, and activities affect your current metabolism, which can impact fitness and weight-loss goals.

Look at your newly calculated carb-consumption goal. Follow the suggested meals and snacks for the day to hit that healthy fat-to-carb ratio. If you’re questioning the number of carbs in certain foods, check with the “food search” feature.

Lumen calls its holistic handheld a sustainable “superpower” because it changes with you. The customized data starts to answer lingering questions, like why your body is storing carbs and why you feel low-energy some days.

handheld wellness device

We can’t guarantee the device works. But if nothing else, it might provide new knowledge about how your body uses its two primary energy sources. And you know what they say about knowledge.

The Lumen is considered a premium wearable lifestyle device, currently available on Indiegogo. Pledge levels start at $179 for early birds, and the retail price is $299. The campaign ends August 25.

Julie Kailus

Associate editor Julie Kailus has spent a career covering people, places, and products in the outdoor industry. Julie can be found testing the latest and greatest in her favorite activities — trail running, mountain biking, swimming, snowboarding, and the underrated endurance sport of chasing two sons around the mountains.