Lunch at a restaurant, with a zero-sugar cola. Forty minutes later the reading stood at 195 mg/dl — sixty-six higher than before. But was it really the cola?
What the sensor recorded
Readings from my own sensor, 24 July 2026. A single observation.
What happened
Until two in the afternoon the day was quiet — the curve hovered around 128. Then came the meal. Within forty minutes the reading climbed to 195, a steeper rise than I usually see. It then fell almost as quickly: an hour later it was at 97.
Twenty minutes on the stepper fell into that downward stretch. Whether that accelerated the fall or whether it would have happened anyway cannot be separated here.
The open question
I ordered the zero-sugar version. Whether I got it, I do not know. The difference in taste is smaller than people think when the glass is cold and you are talking to someone.
There is a second possibility: the vegetables. Some restaurants glaze side dishes with sugar or honey. That would also explain a quick rise — though rarely one this steep.
The pattern points to liquid sugar: very fast rise, short peak, rapid fall. Solid carbohydrates usually act more slowly and last longer. A single reading cannot prove this — it remains a reasoned guess.
What I take from it
Asking costs nothing. Since then I say more clearly in restaurants that I want the sugar-free version — and I look in the glass before drinking. Both are unremarkable and help more than any calculation afterwards.
The second point matters more to me: a single spike is not a disaster. The daily average still came out at 119 mg/dl. What counts is what happens over weeks, not what goes wrong on one afternoon.
This is a single observation with my own sensor, not a study. How strongly sugared drinks affect you depends on your situation. If you regularly see unexplained spikes, that belongs in a conversation with your medical team.
Key points
- Rise from 129 to 195 mg/dl within forty minutes.
- Back down to 97 mg/dl over the following hour.
- The cause remains open: sugared cola or glazed vegetables.
- The steep shape points to liquid sugar but does not prove it.
- Despite the spike, the daily average was 119 mg/dl.
Single observation, not a study.
Sources
This entry is based on my own sensor readings. Where studies are mentioned, they are linked in the text. Continuous glucose monitoring: FreeStyle Libre 3.