I walked up to the booth at CES ready to buy a glucose monitor.
Bright lights, shiny counters, staff handing out little treats and packets of electrolyte powder. Six figures of trade-show budget, probably more, and it showed.
I had just come from the panel. Two people I respect had talked about wearing one of these, and after three years of doubt I was ready to try it and later speak from experience.
So I asked the person selling it one question. What does this do for a healthy person with no blood sugar problem?
I never got an answer I could use. I left with the electrolyte powder and no monitor.
Then I went and read the evidence.
In this episode:
The study that changed how I think about this whole category. Eighteen experts in continuous glucose monitoring were handed twenty reports from adults without diabetes and asked a simple question: would you call this person back? All eighteen agreed on three of the twenty.
What the same authors said about interpreting these reports in people who do not have diabetes, which is the sentence that should give any healthy buyer pause.
How much time a genuinely healthy adult spends above the line your app calls a spike. The number surprised me, and it reframes what the alert on your phone is actually telling you.
Why the device may be reading high in the first place, what a smoothie company has to do with that finding, and why I still find that sentence funny.
Where this technology genuinely earns its place, because it does. A review published in JAMA Internal Medicine three weeks before this episode is clear about the patients who benefit, and I am not interested in pretending otherwise.
Prediabetes, which is a real exception rather than a hedge, and where the evidence points differently.
The strongest argument for wearing one, taken seriously, and what twenty-five randomized trials found when they tested it.
My own numbers, the tablet I take every morning, and why I am comfortable measuring one thing and not the other. That is the whole test, and I apply it to myself before I apply it to anyone else.
And a colleague's unopened blister of patches on a shared desk, which is the shortest version of this entire argument.
If you are weighing whether to buy one of these, there is a four-item test near the end that will take you about five minutes and may save you the money.
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Read the written edition, with all 16 references:
https://www.andreheeg.com
Under Load is the Sunday edition of The Upward ARC, written by Andre Heeg, MD, DDS. Evidence-led writing on executive health, longevity and performance under load, for people carrying real responsibility.
Subscribe: https://www.andreheeg.com
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Studies and sources discussed in this episode are listed in full in the written edition. Key ones:
Dower et al. (2026), JAMA Internal Medicine: continuous glucose monitoring in type 2 diabetes and beyond
Spartano et al. (2025), Journal of Diabetes Science and Technology: expert interpretation of CGM reports from people without diabetes
Spartano et al. (2025), Journal of Clinical Endocrinology and Metabolism: defining CGM time in range in a community cohort without diabetes
Shah et al. (2019), Journal of Clinical Endocrinology and Metabolism: CGM profiles in healthy nondiabetic participants
Hutchins et al. (2025), American Journal of Clinical Nutrition: continuous glucose monitor overestimates glycemia
Liao et al. (2026), European Journal of Medical Research: CGM in non-diabetic populations
Richardson et al. (2024), International Journal of Behavioral Nutrition and Physical Activity: CGM as a behaviour change tool
Hall et al. (2020), Journal of General Internal Medicine: thiazide diuretics and fasting plasma glucose
U.S. Food and Drug Administration (2024), 510(k) K233655: Lingo Glucose System
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This episode is me reading the written newsletter, adjusted for the spoken word. Figures are rounded and citations are left out; everything is fully referenced in the written edition.
AI assisted with research, drafting and adapting this piece for different formats. I chose the argument and examples, reviewed the evidence, edited the final text and take responsibility for every published claim.
Nothing here is medical advice, and it is not a substitute for a conversation with your own doctor. If you have diabetes, prediabetes, symptoms, or another metabolic risk, take this question to your clinician rather than to a newsletter.