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Using a CGM to Personalize Your Diet

Updated July 8, 2026

Wear a continuous glucose monitor for a few weeks to learn which foods and habits spike your blood sugar, then use that personal data to eat for steadier energy. Useful self-experiment, with honest caveats.

📈
Casey Means
Levels / Stanford-trained physician
Not endorsed · Based on the published work of Casey Means
Daily time
2 to 4 weeks
Steps
6
Difficulty
Beginner
Sources
3
View the steps →
What it is

Casey Means' core idea: glucose responses are highly individual, the same food can barely move one person and spike another, so a continuous glucose monitor (CGM) lets you see your own responses and adjust. Worn for a few weeks, it shows which meals give 'small hills' versus 'big mountains', and you use that to pair and time foods better. Two honest notes up front: Means co-founded Levels, a company that sells CGM software, so there is a clear commercial interest, and the value of chasing flat glucose in healthy, non-diabetic people is debated, brief spikes are normal. Treat it as a learning tool, not a verdict on your health.

Why it works▼
Post-meal glucose responses vary a lot between people due to genetics, the microbiome, sleep, stress and activity, so generic glycemic-index charts often mislead. Seeing your own data makes the levers concrete: eating vegetables, protein and fat before carbs, walking after meals, and managing sleep and stress all tend to blunt spikes. The aim is steadier glucose, fewer large swings, which may support steadier energy, though in healthy people the long-term benefit of optimising this is not well established.
The evidence
Sources
Published work by Casey Means, cited straight to the source: long-form episodes, clips, peer-reviewed papers and their own writing. Select any to view it here.
1
Continuous glucose monitoring with Casey Means: what spikes you and why (Levels)
Article
2
Using glucose as a continuous health marker, with Dr. Casey Means (Levels)
Article
3
How CGM gives personal, real-time dietary feedback (Wellness Mama interview with Dr. Casey Means)
Article
Source viewer
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The protocol
Clinical strong human trials Mixed some or emerging evidence Commercial weak or unproven, sold widely Equipment / Test not an evidence claim How we grade →
Wear one, briefly

Use a CGM for a few weeks to learn

2 to 4 weeks is usually enough to spot your patterns; you do not need to wear one forever

It turns abstract advice into your own personal data.

Casey Means / Levels
For this stepTest
Continuous glucose monitor
A short wearing period to learn your responses
Find your spikers

Note which foods spike you personally

Watch for surprises; a food that is fine for others may spike you (and vice versa)

Individual variation is the whole point; generic charts do not capture it.

Casey Means
For this step
No product needed
Sequence your meal

Eat veg, protein and fat before carbs

Front-load vegetables, protein and fat; eat the starchy/sweet part last

Food order and pairing meaningfully blunt the glucose spike from the same meal.

Casey Means
For this step
No product needed
Walk after eating

Move after meals

A 10 to 20 minute walk after meals (or a couple of minutes every half hour)

Light post-meal movement lowers the glucose response.

Casey Means
For this step
No product needed
Mind sleep and stress

Account for non-food spikes

Notice how poor sleep and stress raise glucose; note that exercise and sauna can raise it for healthy reasons

Glucose reflects more than food; context prevents misreading the data.

Casey Means / Levels
For this step
No product needed
Learn, then stop

Apply what you learned and move on

Once you know your patterns, keep the habits; you do not need to monitor indefinitely

The goal is durable habits, not permanent surveillance of every meal.

Casey Means
For this step
No product needed
Is this for you?
Good fit if
  • Not a fit if tracking meals could fuel food anxiety (see cautions)
  • Curious self-experimenters
  • People with energy crashes after meals
  • Anyone wanting to personalise their diet
  • Those with a family history of metabolic issues
Cautions
  • Disclosure: Casey Means co-founded Levels, a company that sells CGM software, so there is a commercial interest in recommending CGMs
  • In healthy, non-diabetic people the benefit of chasing flat glucose is debated; brief spikes after meals are normal, not inherently harmful
  • A CGM is not a diabetes diagnosis tool; if you are concerned about blood sugar, see a doctor for proper testing
  • For some people, tracking every meal can fuel food anxiety or orthorexia; if monitoring makes eating stressful, stop and seek support
  • We may earn a commission on products bought through this page
  • Educational only, not medical advice
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Update history
  • July 3, 2026 Protocol published.
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Not medical advice. This page is for education only and is not a substitute for professional medical care. Consult a qualified clinician before changing your health routine.
Independent curation. YourProtocol.ai is an independent platform. This protocol is based on the publicly available work of Casey Means and is not created, reviewed, endorsed by, or affiliated with Casey Means or Levels / Stanford-trained physician.

Using a CGM to Personalize Your Diet
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