CGM for Non-Diabetics: Should You Wear a Continuous Glucose Monitor?

Levels, Supersapiens, Dexcom... Continuous glucose monitors are trending among biohackers. But are they worth it if you're not diabetic? Here's the data.

Continuous Glucose Monitors (CGMs) were designed for diabetics. Now they're a biohacker staple. But should YOU wear one if your blood sugar is "normal"?

What is a CGM?

A small sensor (usually on your arm) that measures interstitial glucose every 1-5 minutes, sending data to your phone. You see your glucose in real-time, 24/7.

The Case FOR CGMs in Non-Diabetics

1. Your "Normal" HbA1c Hides a Lot

The Variability Problem

HbA1c is an average. Two people with identical HbA1c of 5.2% could have:

Person A: Steady glucose, 80-120 mg/dL all day
Person B: Wild swings, 60-180 mg/dL, averaging to the same number

Person B is metabolically stressed. HbA1c doesn't show this.

2. Personalized Food Response

The same food causes wildly different glucose responses in different people. A CGM reveals YOUR unique response to every meal.

Real discoveries people make:

"White rice spikes me to 180, but sourdough bread barely moves my glucose"
"A 30-minute walk after dinner cuts my spike in half"
"Eating protein before carbs flattens my curve"
"My 'healthy' smoothie is a glucose bomb"

3. Sleep Quality Insights

Overnight glucose should be stable

Ideally 70-100 mg/dL with minimal variation

Dawn phenomenon

Natural glucose rise 4-8am from cortisol. Excessive rise may indicate insulin resistance.

Nighttime dips

May indicate reactive hypoglycemia, especially after late high-carb meals.

4. Exercise Optimization

Glucose and Performance

Pre-workout: Optimal glucose for performance (90-120 mg/dL)
During: Some rise is normal; excessive rise may indicate stress
Post-workout: Glucose often drops as muscles uptake it
Recovery: How quickly you return to baseline indicates metabolic flexibility

The Case AGAINST CGMs for Everyone

1. Cost vs. Value

Option	Cost/Month	Best For
Levels	$199	Biohackers, metabolically curious
Dexcom G7	$300+ (insurance may cover)	Medical use
Libre 3	$150-200	Budget option
Quarterly HbA1c	$20-30	Most people

For most metabolically healthy people, quarterly HbA1c + fasting glucose is sufficient.

2. Anxiety and Obsession Risk

The Dark Side

Some users develop anxiety around glucose readings:

Obsessively checking the app
Fear of eating "wrong" foods
Unhealthy restriction patterns
Stress from normal variations

If you have a history of disordered eating, CGMs may not be appropriate.

3. The Data Can Be Misleading

What CGM Shows	What It Might Actually Mean
Spike after fruit	Normal, healthy response to natural sugars
Post-meal rise to 140	Perfectly normal, not dangerous
Different readings day to day	Normal physiological variation
Lower readings with keto	Not necessarily "better" — just different

A glucose spike to 140 mg/dL after a meal is NORMAL. Biohacker culture has pathologized completely healthy glucose responses.

Who Should Actually Use a CGM?

Strong Candidates

✓

Prediabetic (HbA1c 5.7-6.4%)

✓

Family history of diabetes

✓

Trying to optimize athletic performance

✓

Curious and can afford it without stress

Probably Skip It

✗

Normal HbA1c, no metabolic concerns

✗

History of disordered eating

✗

Prone to health anxiety

✗

Budget is tight

The Middle Ground: One Month Experiment

The 30-Day Learning Protocol

Instead of ongoing CGM use, try one month to learn your patterns:

Week 1: Eat normally, observe your baseline Week 2: Test specific foods — rice vs. pasta, fruit timing, etc. Week 3: Test interventions — walking after meals, protein first, etc. Week 4: Refine your personalized eating strategy

Then stop wearing it. Apply what you learned.

What "Good" CGM Data Looks Like

Optimal Patterns

Metric	Target
Fasting glucose	70-90 mg/dL
Post-meal peak	< 140 mg/dL
Time to baseline	< 2 hours
Overnight	Stable 70-100 mg/dL
Daily variability	< 30 mg/dL standard deviation

Red Flags

Frequent spikes > 160 mg/dL
Not returning to baseline within 3 hours
Fasting glucose consistently > 100 mg/dL
Large dawn phenomenon (> 30 mg/dL rise)
High variability despite consistent diet

Alternatives to CGM

Quarterly Lab Work

HbA1c, fasting glucose, fasting insulin, HOMA-IR

Post-Meal Glucose Testing

Cheap glucometer, test 1 hour after specific meals

Oral Glucose Tolerance Test

One-time test showing how you handle glucose

Fasting Insulin

Often more predictive than glucose alone

Using Genki with CGM Data

Integrate Your Glucose Data

With Genki, you can:

Import CGM data alongside your lab work
Correlate glucose patterns with other biomarkers
Track the impact of lifestyle changes over time
Store everything locally and privately

The Verdict

"
CGMs are a powerful tool — for the right person, at the right time. They're not necessary for everyone, and they're not the path to immortality that some biohackers suggest.
Use them to LEARN, not to obsess. Then apply what you learned and move on.
"

— The Balanced View

The best CGM strategy: One month to learn your patterns, occasional check-ins if prediabetic, or skip entirely if you're metabolically healthy and can't afford the cost and cognitive load.