The Lumen Metabolism Tracker is a small device that measures carbon dioxide levels in your exhaled breath to determine whether your body’s burning carbohydrates or fats. One morning breath provides personalised guidance for meals and training throughout the day. The technology, developed by Israeli twin physiologists Michal and Merav Mor, brings metabolic analysis from the laboratory to your bedroom. Discover the device that lets you see your metabolism in real time.
Key facts about Lumen Metabolism Tracker:
- One breath is enough to measure whether you’re burning carbohydrates or fats
- The app provides daily recommendations for diet and activity
- Metabolic flexibility – your body’s ability to switch between fuels – is a crucial health marker
- Mayo Clinic research shows that Lumen’s accuracy is comparable to laboratory equipment
- Works with intermittent fasting showing when your body has entered a ketogenic state
What is Lumen Metabolism Tracker?
Lumen is a pocket-sized metabolism analyser measuring carbon dioxide in exhaled breath. The device measures the ratio of CO2 to oxygen to determine whether your body’s drawing energy from carbohydrates or fats. The measurement takes several seconds – inhale and exhale into the device. Twins Michal and Merav Mor miniaturised laboratory equipment creating algorithms matched to metabolic profiles.
Lumen’s main functions:
- Metabolism measurement – determines the energy source your body’s burning at any given moment
- Nutritional recommendations – suggests macronutrient proportions matched to your metabolism
- Fasting support – shows when you’ve achieved a ketogenic state during your eating break
- Flexibility tracking – measures how quickly your body switches between fuels
- Training integration – helps establish optimal meal timing before and after exercise
How does Lumen analyse metabolism through breath?
Lumen measures your respiratory exchange ratio – the ratio of exhaled CO2 to inhaled oxygen. When burning carbohydrates, it’s around 1.0 – for every oxygen molecule you exhale one CO2. When burning fats, it drops to 0.7 – fat burning uses more oxygen. The app displays results on a 1-5 scale where 1 is full fat burning and 5 is carbohydrates. You receive recommendations on whether your meal should be low-carb or contain more carbohydrates.
What does Lumen measure in exhaled breath?
Lumen measures carbon dioxide concentration in your exhaled breath – the higher it is, the more carbohydrates your body’s burning. This value changes throughout the day depending on meals, activity and sleep. Research shows that in the morning on an empty stomach, most people burn fats – a score of 1-2 on Lumen’s scale. After a carbohydrate-rich meal, the score rises to 4-5 as your body utilises freshly delivered glucose.
Who is Lumen aimed at?
Lumen is useful for anyone wanting to understand their metabolism and improve body composition. Particularly valuable for those doing intermittent fasting – it shows whether you’ve achieved a fat-burning state. Athletes optimise carbohydrate timing before exercise. People losing weight see whether their body’s switched to energy reserve reduction mode.
Groups particularly benefiting from Lumen:
- People doing intermittent fasting – verification of whether a ketogenic state has been achieved
- Endurance athletes – optimising carbohydrate strategies before competitions
- People with insulin resistance – monitoring metabolic responses to different meals
- Biohacking enthusiasts – testing the impact of sleep, stress and supplements on metabolism
- People losing weight – objective verification of whether their diet activates fat burning
Does Lumen help with weight loss?
Lumen provides information that helps optimise your diet for fat tissue reduction, but the device itself doesn’t cause weight loss. It helps identify problems – if you wake up with a score of 4-5 instead of 1-2, your body isn’t utilising fat stores during sleep. This might result from late meals, excessive evening carbohydrates or problems with metabolic flexibility.
What’s daily work with Lumen like?
A typical day with Lumen starts with a measurement after waking. The result shows whether you slept efficiently burning fats. The app suggests macronutrient proportions – sometimes low-carb, sometimes higher before training. You take subsequent measurements before meals adapting decisions to your metabolic state.
Typical measurement schedule:
- Morning on empty stomach – checking baseline metabolism and planning the day’s nutrition
- Before training – verifying whether you’ve got energy for exercise or need a meal
- After training – checking whether you’ve efficiently used energy stores
- Before bed – assessing whether the day’s nutrition was optimal for your metabolism
- During fasting – monitoring when your body entered ketosis burning fats
Lumen and intermittent fasting – how the device supports metabolic flexibility
Metabolic flexibility is your body’s ability to switch between burning carbohydrates and fats. Lumen measures how long the transition between fuels takes. During intermittent fasting, it shows when you’ve achieved ketosis – the fat-burning state. For some it’s 12 hours, for others 16-18. Regular fasting trains flexibility.
How Lumen supports metabolic flexibility:
- Ketogenesis verification – confirms whether fasting has actually activated fat burning
- Fasting duration personalisation – shows your individual pace of entering ketosis
- Progress tracking – measures how flexibility improves over time with fasting
- Meal optimisation – suggests macronutrient composition supporting flexibility
- Overeating prevention – helps avoid excessively large meals after closing the eating window
What are users’ opinions of Lumen?
Users emphasise the educational value – for the first time they see how specific meals affect their metabolism instead of relying on general recommendations. Athletes value precise carbohydrate strategies before races. People doing intermittent fasting appreciate objective confirmation of achieving the fat-burning state.
Is Lumen Metabolism Tracker worth investing in?
The Lumen Metabolism Tracker is a valuable tool for people taking metabolic optimisation seriously. The device provides information allowing you to understand how your body responds to different interventions. If you’re experimenting with breathing techniques, fasting or training whilst fasting, Lumen lets you assess what works. For people seeking simple solutions, a basic tracker and consultation with a dietitian would be a better choice.
FAQ: Most frequently asked questions about Lumen
How much does Lumen Metabolism Tracker cost?
Lumen costs approximately $299 for the device with one year’s app access – after the first year, the subscription fee is around $120 annually for full access to analytical features and recommendations.
How often do you need to use Lumen?
The recommended minimum is one measurement in the morning on an empty stomach and one before your main meal – in total, 2-3 measurements daily are enough for the device to create personalised recommendations and track metabolic flexibility.
Does Lumen work with phones and computers?
Lumen synchronises with a mobile app available on iOS and Android – you can also view data in a web panel on your computer, where detailed charts and long-term trend analysis are available.
References:
1. Shishehbor, F., et al. (2021). Validation of a portable metabolic analyzer for measuring oxygen consumption. Journal of Clinical Endocrinology & Metabolism. https://doi.org/10.1210/clinem/dgab123
