Is a glucose meter useful if you don't have diabetes?
Without diabetes, a glucose monitor gives you some genuinely interesting information about how your body responds to food, exercise and stress. But that monitoring actually leads to better health has not yet been demonstrated.
A continuous glucose monitor, or CGM, measures your blood sugar around the clock via an adhesive sensor patch. A study of 153 healthy people aged 7 to 80 found that those values sit between 70 and 140 mg/dL 96% of the time, with an average of 98-99 mg/dL. People over 60 averaged 104 mg/dL. Useful as a reference point, but it says nothing yet about whether monitoring actually makes you healthier.
There are indications that CGM can detect early disturbances in blood sugar regulation. In a cohort of more than 7,000 people without diabetes, higher average values were associated with abnormalities on retinal photographs and a worse sleep pattern. These are observational associations: whether the higher blood sugar is the cause, or whether a shared underlying factor is at play, cannot be concluded from this.
Among endurance athletes, CGM is increasingly used to fine-tune nutrition around training. Scientific guidelines on how to interpret that data in athletes are still lacking. Notably, after one week of extremely intense training, healthy test subjects showed a measurable deterioration in their blood sugar regulation. Elite athletes showed demonstrably worse glucose regulation via CGM than a comparable control group. CGM therefore sometimes reveals unexpected patterns in athletes that would otherwise go unnoticed.
Researchers are also combining CGM data with AI. In a study of around 28,000 participants, an AI model trained on CGM and dietary data outperformed existing methods in predicting disease. Interesting, but this is still early-stage research and cannot simply be translated to your personal sensor.
The clinical benefit for healthy people has not yet been demonstrated in long-term, controlled research. How best to interpret CGM data outside a medical context, whether monitoring leads to better choices, and whether those choices ultimately produce health gains, remains unclear. In addition, a sensor can cause anxiety or unnecessary worry about normally fluctuating values.
All claims are based on observational studies and cohort research, not on randomised controlled studies with hard health outcomes in healthy people. The strength of the evidence is therefore limited to moderate.