I used to believe I had health figured out.
I ate nutritious foods, stayed active, and made sleep a priority.
But one morning, everything changed with a breath.
I blew into a device no bigger than a lipstick tube, and it told me something surprising: my body was burning carbs, not fat, even though I hadn’t eaten. That single breath didn’t just tell me what I’d eaten the night before. It revealed how my metabolism was behaving in real time.
Metabolism might sound like a complicated word, but it’s really just how your body uses energy. It’s what keeps you alive. It helps you turn food into fuel, repair your cells, and keep your heart beating. You can think of metabolism as the silent engine inside you that’s always running even when you're asleep.
And it operates in two main ways: catabolism, which breaks things down to make energy, and anabolism, which builds things up using energy.
The trick is to keep this engine flexible. A flexible metabolism means your body can switch between burning carbs and fats depending on what it needs.
That’s where Lumen comes in.
It’s a smart little device that asks you to breathe in, hold it, and breathe out slowly. In those few seconds, it measures the carbon dioxide you exhale. That gives it clues about what kind of fuel your body is burning: carbs or fat.
After each breadth, you get a lumen score between 1 and 5:
Score | What it means | Fuel score |
|---|---|---|
1-2 | Body is burning stored fat | Fat-dominant |
3 | Balanced mode | Fat + carbs |
4-5 | Body is burning recent carbs | Carb-dominant |
High scores in the morning might indicate poor sleep, stress, or high carb intake the night before. Low scores reflect fat burn, ideal during fasting or post-sleep reset.
But Lumen isn’t just a tracker. It’s a coach in disguise. If your score is high, it gently suggests lowering your carb intake. If your score is low, it celebrates that your body is burning fat effectively. Over time, you learn how to train your metabolism just like you’d train a muscle.
The device doesn’t dictate what you should eat, it helps you understand why your body feels like eating certain things.
In just a few weeks, everything changed for me. I stopped guessing what my body needed. I started making choices based on how my breath responded. I learned how to time my meals better. I became more aware of how sleep, stress, and food shape my internal rhythm. Lumen made my metabolism something I could see, understand, and adjust. It wasn’t just technology. It reshaped the way I thought about my body.
No labs, no needles, no confusion.
Just breath.
One inhale, one exhale, and a number that teaches you more than any diet ever could.