A client sends you a screenshot. One number: 140 mg/dL.
What does it mean?
If your first instinct is "too high" or "that's fine," you're reacting to a word, not a sentence. And in the new language our clients are wearing, a single word rarely tells you anything useful.
Why One Reading Misleads
A continuous glucose monitor records a reading every few minutes, all day and night. Any one of those readings is a single frame pulled out of a moving picture.
That's why the international consensus on CGM use recommends reviewing about 14 days of data before drawing conclusions, even in diabetes care.¹ The experts who use this technology most closely don't judge a person by one number. Neither should we.
It also helps to know what normal life looks like. In a multicenter study of 153 healthy, nondiabetic participants, people spent a median of about 30 minutes a day above 140 mg/dL.² A brief rise into that range after a meal is part of ordinary physiology for many people. On its own, it is not a verdict.
Context Is What Turns A Number Into A Sentence
A glucose reading only makes sense alongside the life around it. What someone ate matters, and identical meals can produce very different responses from person to person.³ ⁴ Movement matters too: a meta-analysis found that breaking up sitting with light walking lowered post-meal glucose compared with sitting continuously.⁵
Sleep plays a part as well. In the PREDICT study, poorer sleep efficiency, later sleep timing, and departures from a person's usual sleep pattern were each linked with higher glucose after breakfast the next morning.⁶ Illness, travel, a hard workout, or a stressful morning all belong in the story. Ask before you assume.
Same Number, Different Sentences
Take two clients who both see 140 mg/dL after lunch.
The first ate lentils, roasted vegetables, and a little Greek yogurt, then took a short walk. Lentils and other legumes sit among the lowest-glycemic foods measured.⁷ Within the hour, their glucose had settled back toward their usual baseline.
The second slept poorly, rushed through a stressful morning, and sat at a desk all afternoon. Their glucose stayed elevated for hours.
Same number. Completely different sentences. And completely different conversations for you to have.
Where Professionals Get Into Trouble
When we react to a single word, three things tend to happen:
We Overcorrect. A client cuts out a food that was never a problem for them.
We Create Worry. A normal rise gets treated like a warning sign, often because the targets we reach for were written for diabetes care.¹
We Waste The Data. We give the same general advice we'd have given without the sensor at all.
None of these build trust. A client who brought you their data deserves a response that shows you understood it.
How Fluency Builds
Fluency in any language takes time. Slowly, you learn to hear meaning in context instead of reacting to single words.
That's the skill I've spent over 20 years building while reading CGM data. It never starts with a single number.
What Comes Next
Next in the We're Wearing a New Language series: every language has a grammar, and glucose is no exception.
Want to see what reading glucose in context looks like with real examples? The free masterclass shows what's possible. The certification teaches you how to do it.
References
Battelino T, Danne T, Bergenstal RM, et al. Clinical targets for continuous glucose monitoring data interpretation: recommendations from the international consensus on time in range. Diabetes Care. 2019;42(8):1593-1603. doi:10.2337/dci19-0028
Shah VN, DuBose SN, Li Z, et al. Continuous glucose monitoring profiles in healthy nondiabetic participants: a multicenter prospective study. J Clin Endocrinol Metab. 2019;104(10):4356-4364. doi:10.1210/jc.2018-02763
Zeevi D, Korem T, Zmora N, et al. Personalized nutrition by prediction of glycemic responses. Cell. 2015;163(5):1079-1094. doi:10.1016/j.cell.2015.11.001
Berry SE, Valdes AM, Drew DA, et al. Human postprandial responses to food and potential for precision nutrition. Nat Med. 2020;26(6):964-973. doi:10.1038/s41591-020-0934-0
Buffey AJ, Herring MP, Langley CK, Donnelly AE, Carson BP. The acute effects of interrupting prolonged sitting time in adults with standing and light-intensity walking on biomarkers of cardiometabolic health in adults: a systematic review and meta-analysis. Sports Med. 2022;52(8):1765-1787. doi:10.1007/s40279-022-01649-4
Tsereteli N, Vallat R, Fernandez-Tajes J, et al. Impact of insufficient sleep on dysregulated blood glucose control under standardised meal conditions. Diabetologia. 2022;65(2):356-365. doi:10.1007/s00125-021-05608-y
Atkinson FS, Brand-Miller JC, Foster-Powell K, Buyken AE, Goletzke J. International tables of glycemic index and glycemic load values 2021: a systematic review. Am J Clin Nutr. 2021;114(5):1625-1632. doi:10.1093/ajcn/nqab233
