Lumen is the first device and app available to anyone that provides real-time feedback on whether you’re burning carbohydrates or fats. These measurements are usually only made for athletes or patients through special testing centers, hospitals, or clinics, but with Lumen they are now available to everyone, anywhere. Nutrition is a very individualized topic, while metabolism is just as nuanced – one size does not fit all when it comes to diet and nutrition plans – and that’s why dieticians and nutrition coaches can play an important role in health and well-being. However, a personalized diet comes with a need for experimentation because fine-tuning is often necessary. Every body processes foods and nutrients just a bit differently, and this is where a device like Lumen can really aid in that individualized understanding of one’s metabolism. We got a chance to try out the Lumen ourselves, which is a very sleek and compact device. It comes in a nicely designed box with everything you need to get started – with a charging base, cord, and booklet. Its exterior has a matte finish that makes it soft to the touch, and its cap attaches via magnets, which makes removing and putting the cap on and off enjoyable. Pairing the device via Bluetooth, once the Lumen app is downloaded to your smartphone, is very straightforward, and the lights and user interface are simple to understand and use. The device actually holds charge quite well, since after three months of measurements it still maintains power. One of my favorite things about Lumen is that the team is constantly making updates to their product and providing valuable information and education to the user – the amount of knowledge and experience the twin sister founders, Drs. Merav and Michal Mor, and their team brings is very apparent throughout the product experience. Before we talk about the Lumen metabolism journey, let’s discuss a bit about the science. Lumen’s proprietary technology uses a CO2 sensor and flow meter to determine the CO2 concentration in a single breath. A fixed volume of air is inhaled through the device (dynamic to each individual), and that breath is held for ten seconds before exhaling fully. Over one million breath measurements are taken per month, and these measurements allow the company to keep improving their metabolic measurement platform. A peer-reviewed article has also been published showing the validity of Lumen to estimate metabolic fuel utilization in a comparable manner with the gold-standard metabolic cart. Over the course of a couple of weeks, I was able to use Lumen to learn a lot more about how my body processes various types of foods, how it burns carbs versus fats before and after exercise, while fasting, or after other activities. It took a few days to get comfortable with taking measurements, mostly because I was slouching, and learning to sit up when inhaling makes a huge difference. But by a month into my journey, I’d been able to shift my body’s metabolism to be on a fat-burning streak by learning how to adjust my diet through trial and error. Measurements are taken at the beginning of the day, usually after you’ve been awake for an hour but before anything has been consumed, and these first two weeks of morning measurements are used to establish your baseline and what’s called your “Lumen Flex score.” The Flex Score tracks how flexible your metabolism is, which reflects how well your body can shift between fuel sources. A great metabolism is one that is very flexible, where your body is encouraged to mostly burn fat. After that initial morning measurement is taken, a personalized nutrition suggestion based on macros will be created (such as 90g carbs, 92g fats, and 112g protein). This is where Lumen has gone above and beyond – they have a Recipe Guide for breakfast, lunch, dinner, and snacks that I see getting updated all of the time, with detailed breakdowns of ingredients and other information. Even if you don’t make their recipes, they allow you to scan in or log foods just like apps such as MyFitnessPal with similar dashboard views of what you’ve consumed broken down into macro groups. There’s even a “build your own meal box” option starting from $9.09 per meal for those inclined to use that service. But one of my other favorite things about this company is how they are invested in making nutrition accessible and understandable to the average consumer. I love that they have spent so much effort producing content to aid in your metabolic journey, whether it’s a motivational video, coaching video, exercise video, or scientific video. “Lumen learning” was one of my favorite sections to get started learning more about the device and metabolic flexibility, and the associated articles on tips and insights have all been great to break down what might otherwise feel daunting as you begin on this journey. Lumen provides as initial onboarding call with one of their experts, and I would highly recommend scheduling that call as it helps answer many initial questions. Overall, I have had a great product experience, and really felt that each feature and piece of content in their app was well thought out. Their support team is also very quick at answering questions. I feel like the team has taken metabolism, something that for most people may seem out of reach and made it accessible and understandable to anyone. Finally, we had the pleasure of interviewing Lumen co-founder Dr. Michal Mor. Alice Ferng, Medgadget: Can you please tell us more about yourself and what inspired you to develop this product? Dr. Michal Mor, Co-Founder of Lumen: I was born in Palo Alto, California but moved to Israel when I was two years old along with my mother and three siblings, including my twin sister Merav. After serving in the Israeli army, both Merav and I studied at Ben Gurion University of the Negev. We both hold BSc in Medical Laboratory Sciences and MSc in Physiology, and I have a PhD in Physiology in Cardiac Science, while Merav has a PhD in Physiology in Heart Arrhythmia. When we (my sister Merav and I) were training for the Ironman we had to manage our nutrition very carefully to succeed. We had a lot of questions such as what to eat and when.We tried different things- we tried to eat our larger meals like chicken and rice at 5 in the morning and other crazy experiments to fuel the race. We wanted to fuel and train our bodies to use fat as an energy source for the remainder of the race in the running portion of the Ironman, where athletes typically crash. Although we succeeded with a smile, we couldn’t find a clear answer so we did some research on the available solutions out there and discovered there is a huge gap between the basic science around nutrition and the average person trying to understand what they should eat on a daily basis. That’s why we made it our mission to make metabolic testing available for all, and we started on our journey to create out first prototype which looked like a video casette. Today our Lumen device fits in the palm of your hand and works as well as a metabolic testing machine typically only available in labs and clinics. Medgadget: What were some of the hardest challenges to overcome during product development? Dr. Mor: Creating a hardware product is a challenge since the cycle of a hardware product is very long, and then having a science-backed hardware product is an even bigger challenge. We had to take a 45-minute RER test which is the traditional way of measuring metabolism, and turn into a process which is based on a breath or two, in a less than minute. Having a science-based product also has its usability challenges. It’s important to make something that translates to the real world, and not only the lab. This is why we made many iterations to to the product itself and our app to make it as user friendly as possible. Another challenge is making people aware of the concept of metabolic health, and of course creating a behavioural change that would enable people to make better daily nutrition choices. Medgadget: How do you intelligently fine tune the Lumen device results – are the breath results normalized for the same individual over time? Or across your pool of users over time? Dr. Mor: When our users initially start measuring their metabolism with Lumen, we learn from other individuals like them to predict their measurements . This is also powered by an algorithm based on existing measurements from our entire user base. We record over 1 million metabolism measurements a month from our customers. So this gives us two strong sources of input to provide the highest quality reading which becomes more and more individualized as our users breathe into the device over time. We are also peer-reviewed and our technology has been validated to work as efficiently as a traditional metabolic cart. Medgadget: The utility of Lumen spans a couple key areas of life, but the actual RER measurement is limited in what it can tell you – are there any other devices or tests that you sometimes pair with use of this device? Dr. Mor: This is true- we are all about measuring the impact of lifestyle on your metabolism. These are key lifestyle habits around sleep, your fasting window, exercise, steps and of course your nutrition. Our goal is to let you see the impact of this on your body and metabolism so that you can keep improving these areas of life. The Lumen RER-based measurement then tells you where these push your body fuel- towards fat or carb burn, but that’s only the beginning. We can rely on lots of data and algorithms to predict your progress around your health and weight management. In essence, while RER is very specific, it’s actually a great start to giving actionable advice on how much you should sleep for your own metabolism, how many steps do you need to take for a a positive health reading, how many hours you should fast and more. This helps us create your nutrition program as well, starting from meal plans to your macronutrient amounts (the precise volume of fats, carbs and proteins) all based on your daily metabolism measurement. We pair with other devices such as Garmin, and connect with Apple health and google with the consent of our users. We have also developed our own Apple watch app. Our users often own other wearables like the Oura ring, and they report seeing a major correlation between their sleep quality and the health of their metabolism. We have also launched successful API or data integrations with companies like Garmin, where users who own Garmin devices can see the impact of their workouts on their metabolism in real time. Medgadget: What’s your vision moving forward? Any upcoming developments you can share? Dr. Mor: We’d like to create a product experience which seamlessly adapts to your lifestyle- a journey to health which gradually takes you from whatever starting point (obesity, high blood sugar) to optimal metabolic health where you feel more energy, adopt healthy eating habits and exercise more regularly. It starts with helping you understand your metabolism purely from an educational level, with digestible content which takes you through understanding your body, how it uses energy and what to do about it in life. We then want to gamify your insights around your metabolism- really revealing the impact of your sleep, steps, exercise, fasting hours and of course food intake on your overall health. We want our users to understand what their special food, routine and timing that they eat is. It’s about helping you discover your metabolism , something within you that natural regulates your energy, weight, muscle building, sleep and quality of life. We then help coach you through what you should be eating, doing and exercising daily based on your metabolism measurement. Some days we work out, some days we are sit many hours on a chair at work so we need an approach that adapts to us. Overall that means developing hundreds of in-app videos of content, gamifying the app experience so that you can improve your metabolic health and integrating with other health apps so that you can continue tracking the impact of what you’re doing already on your metabolism. Medgadget: Anything else you’d like to highlight for our Medgadget readership? Dr. Mor: Yes, I’d like to add that we often underestimate the value of taking care of our metabolism. And we often assume that it dies with age and that there’s nothing to be done about it. While [88% of Americans](https://www.unc.edu/posts/2018/11/28/only-12-percent-of-american-adults-are-metabolically-healthy-carolina-study-finds/#:~:text=Data revealed that only 12.2,factors management%2C according to researchers.) are metabolically unhealthy, there is definitely so much we can do to improve our metabolism. You can become more metabolically flexible, which means being able to switch efficiently between fats or carbs as an energy source. That means you can eat certain foods at certain times that would work for your body to function at its best and use carbs for energy instead of storing them as fat. Of course, having a device like Lumen helps you track your metabolism, get a metabolic flexibility score and improve it. However you can also follow certain pillars to maintain a healthy metabolism. Five things you can do: Go low-carb and gradually increase. This will help empty your glycogen stores so that you use fat as fuel. Intermittent fasting- See what hours work for you. We know that typically our users see good results between 12-14 hours of fasting. It helps empty your carb stores. Cardio workouts- they’re a great way to burn through carbs and you only need about 30 minutes of movement for impact. Most of our users are able to wake up burning fat after 5000 steps, which is half of the 10 thousand people usually recommend. Increase your strength workouts- these help increase the mitochondria in your body- the power plants that convert food into fuel for your body. We want more of these as we age to feel and function at our best. Focus on macronutrients not calories- when we look at calories only we don’t think of the quality of our diet. Macronutrients involve the amount of fats , carbs and protein we eat. So it’s about making sure we get enough of each. You can start by filling up half your plate with vegetables and eating lean proteins like fish, tofu or even adding olive oil to a salad. Research (Calcada et al, Gormsen et al) finds that metabolic flexibility has a profound role in assessing a person’s health. People with good metabolic flexibility: Find it easier to lose weight and maintain it. Are in a better position to gain muscle and perform better during workouts. Are at lower risk of developing obesity, diabetes and metabolic disorders. Source