A growing number of healthy people are wearing continuous glucose monitors — small disc-shaped sensors that read interstitial glucose every minute. Companies like Levels, Nutrisense and Lingo have made them mainstream. The question is whether they're actually useful for non-diabetics.
What a CGM measures
A CGM reads glucose from the fluid between cells, sampled by a tiny filament under the skin. Modern sensors are accurate to within ±10% of a finger-stick reading and last 14 days per sensor.
What you'll learn in the first 2 weeks
- Your personal glucose response to specific foods (it varies a lot between people)
- How sleep quality affects your fasting glucose the next morning
- Whether stress meetings raise your glucose (yes, often)
- How exercise placement before vs after meals changes the curve
- Whether "healthy" foods like granola or smoothies actually spike you
The honest case for wearing one
- You'll learn which "healthy" foods don't agree with you, individually
- It motivates real behavior change (walking after dinner, smaller portions)
- It catches early insulin resistance years before a fasting glucose test would
The honest case against
- Costs $50-200/month — pricey for what you can mostly learn in 2 weeks
- It can make people food-anxious, chasing flat lines instead of eating well
- Most "spikes" in healthy people are completely normal physiology
- Glucose isn't the only metabolic signal that matters
Bottom line
If you can afford a single 2-week sensor as an experiment, it's genuinely educational. Long-term wear for non-diabetics is more of a luxury than a necessity — the lessons compress quickly.