Lumen
Two-minute review Are you currently burning carbohydrates or fats? Lumen, a small breathalyser equipped with Bluetooth to sync with an app for smartphones and Apple Watch , will tell you. Why do you need to know? Your body’s metabolism is so important. It gives energy to cells and organisms and plays a critical role in weight loss. But while fitness trackers , smartwatches , heart rate monitor and smart scales will tell you precisely what activities you've done and monitor your progress – be that better fitness or weight loss – they won’t tell you how efficient your body is at burning calories, or what and when to eat. Lumen helps you achieve ‘metabolic flexibility’. That’s effectively when you start the morning burning mostly fat and then swap to carbs depending on your activity. Cue better energy levels overall, more efficient weight loss, and being able to see the effect on your body of a workout/run/swim/hike. Is it backed by science? Lumen says its device has been vali...