By Nicole Nguyen

The latest smart wearable got under my skin.

Two weeks ago, I used an applicator with an intimidating needle to lodge a tiny wire into the back of my arm. Since then, the sensor has sent my blood-sugar levels to my phone every 15 minutes.

The high-tech patch is a continuous glucose monitor -- well-known by people with diabetes, but now available to others. Stelo by Dexcom was the first over-the-counter monitor approved by the Food and Drug Administration last year. Abbott's Lingo is another option. Both are for adults who don't take insulin, and part of a growing slate of sensors for health-curious people.

The device can show you whether your breakfast is causing a glucose spike and a subsequent energy crash. Combining it with the Oura smart ring, which recently introduced a metabolic health feature, can reveal if bad sleep or sedentary days are making your levels worse.

Doctors I spoke to say monitoring glucose spikes could be helpful for people with higher than normal blood sugar, or prediabetes, which affects one in three Americans. But what about those without any risk factors? Does that extra data help?

I turned to different AI-powered interpreters to help me make sense of it all, including the Stelo and Oura apps, as well as Anthropic's Claude chatbot. I also asked real live human doctors for their takes. The tiny implant didn't change my life -- but its data led me to some pointers I'll consider before my next sugar fix.

The default: Stelo

The glucose biosensor can last up to two weeks. They sell for $99 a pair -- doctors sometimes recommend doing two testing stints, for maximum data. It's waterproof and sticks with adhesive so it doesn't fall out. I was surprised the application didn't hurt. Most days, I forgot I was wearing one, though it did catch on a few tank-top straps.

My goal was to spend one week eating a range of foods, and the next week implementing changes to turn steep peaks into rolling hills.

The Stelo app is simple. A big number up top represented my latest reading, expressed as milligrams per deciliter. Below that, a graph plotted fluctuations in my blood sugar in five-minute increments. Every week, the app highlighted the days my levels stayed within a healthy range at least 96% of the time, which it says experts recommend.

But it doesn't go deep. When the app detected sugar spikes, I had to ask: Was it a meal, stress, activity or something else?

The upgrade: Oura

Oura's app is less of a guessing game. I wear an Oura ring ($349 and up, plus a $6 monthly subscription) to track sleep, stress and activity. The app's new glucose feature superimposes all of that data with Stelo's readings, so you can see what else affects your blood sugar. It looks fun but it's overwhelming.

The interesting stuff was below the graph, where Oura rated each day from "fair" to "elevated," based on how long my levels stayed within the ideal range. On a bad day, Oura recommended a protein-rich snack and light evening activity.

Oura has an AI camera feature for logging meals, and that added another layer of insight. I learned that an all-you-can-eat crawfish boil didn't make my blood sugar spike. But a sweet-and-salty cracker mix made my levels soar.

The app repeatedly suggested postmeal walks, so after a visit to an ice cream shop, I tried it. Sure enough, I strolled off two scoops without ever getting out of range.

The chatbot: Claude

Privacy experts warned me not to upload medical data to chatbots, and I have passed that warning on to you. But in the name of research, I gave it a shot.

I took precautions: I used Anthropic's Claude, which has strong privacy defaults, and removed personal information from the uploaded file.

Claude observed that I'm normal. It pointed out that my levels are more stable on days with exercise. "Any tweaks would be minor optimizations rather than health necessities," it said. Translation: You probably shouldn't bother with a chatbot -- for now.

The doctors: Sos Mboijana and Sarah Kim

Dr. Sos Mboijana, an internal-medicine physician with Kaiser Permanente in Washington, D.C., experimented with a monitor and learned that after-dinner dark chocolate didn't raise his blood sugar as much as granola and milk. "That's helpful to me," he said.

However, people shouldn't fear the spike. "Glucose spikes happen in everybody, diabetic or non-diabetic," he said. They should only call a doctor if they observe their blood sugar staying high, he advised.

Dr. Sarah Kim, a professor of medicine at University of California, San Francisco, reviewed my graphs and wasn't concerned, even on days with out-of-normal-range spikes. A monitor might offer helpful feedback for someone at risk of diabetes, Kim said, but for most people, it's "probably not telling you something you didn't realize already."

Like the apps said: Balance carbs with protein and fiber, stay active and don't stress. Not exactly groundbreaking.

If anything, seeing the effects of good and bad behavior firsthand helped reinforce those decisions in my life. Before this experiment, it was easy to convince myself that several small handfuls of party mix isn't a lot. Now I've seen the stats! The next time I dive into some carby goodness, I will also take a walk.

Write to Nicole Nguyen at nicole.nguyen@wsj.com

(END) Dow Jones Newswires

June 01, 2025 09:00 ET (13:00 GMT)

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