Sarah, a 34-year-old marketing manager I spoke with recently, spent $1,200 last year on a continuous glucose monitor (CGM) and the subscription to go with it. She has no diabetes, no prediabetes, and no family history of metabolic disease. She wanted to understand how her body responded to different foods so she could "optimize" her energy and avoid the afternoon slumps that had plagued her since her 20s. "Everyone at my gym was talking about it," she told me. "I figured, why not?"
She is far from alone. Across the country, healthy people without diabetes are strapping on CGMs, devices once reserved for patients who needed to track blood sugar in real time to manage a serious chronic illness. A device that was niche five years ago is now quietly mainstream, driven by fitness influencers, wellness entrepreneurs, and a growing industry that promises insights into your metabolic health that standard checkups miss. In March 2024, the FDA authorized the first over-the-counter CGM device, removing the prescription barrier and making these monitors accessible to anyone with a credit card and curiosity [6].
What the Numbers Actually Show
The appeal is obvious. CGMs offer a real-time window into what happens inside your body after a bowl of pasta or a tough workout. But what can that data really tell you if you don't have diabetes?
Harvard Health published an analysis noting that in studies of non-diabetic people, blood sugar remained in the normal range about 96 percent of the time [1]. That is a striking figure. If your body is already keeping things steady, what exactly are you learning from watching the other 4 percent? The same analysis pointed out that CGMs cost thousands of dollars per year out-of-pocket, and that rigorous research proving health benefits for non-diabetics is sparse [1]. Marketing claims about metabolic "optimization" remain largely unproven.
A more recent study from Mass General Brigham, published in April 2025, examined 972 adults and found that CGM metrics aligned closely with HbA1c test results in people with diabetes, weakened in those with prediabetes, and essentially disappeared in non-diabetics [2]. The researchers concluded that "CGM data is not a substitute for HbA1c," and that while the devices may offer some utility as behavioral biofeedback, they do not reliably reflect longer-term metabolic control in healthy individuals [2].
The Case for Personalization
Not everyone is convinced the case against CGMs is closed. A systematic review published in the European Journal of Medical Research noted that substantial glucose variability is actually common in non-diabetics, particularly after meals [3]. Healthy individuals can spike above 140 mg/dL after eating despite having completely normal HbA1c results [3]. The standard lab tests, in other words, may be missing something that CGMs can catch.
This is where the conversation gets more nuanced. A large study called the 10K Project, published in Nature Communications Medicine in 2023, tracked 8,025 non-diabetic adults who wore CGMs for three or more days [5]. The findings revealed substantial glucose variability even among metabolically healthy people, and identified distinct patterns across individuals that the researchers argued support a more personalized approach to nutrition [5]. The idea is not that spikes are dangerous, but that different people respond differently to the same foods, and CGMs might help identify those differences.
The sports science community has taken this and run with it. Research from the Gatorade Sports Science Institute, published in 2024, found that CGMs are increasingly used by athletes without diabetes to inform nutrition and training decisions [4]. These monitors reveal individual responses to food and exercise that standard lab tests simply cannot capture. The research noted that athletes without diabetes can reach glucose levels above 160 mg/dL during training without any pathological significance [4]. For athletes, that kind of data is not about diagnosing a problem. It is about understanding how your body fuels and recovers from hard effort.
The Other Side of the Coin
For all the excitement, some experts urge genuine caution. Harvard Health's analysis raised a point that is easy to overlook in all the enthusiasm for personal data: if your blood sugar is mostly normal, normalizing every small fluctuation can backfire [1]. People may respond to minor drops in glucose by eating more than they need, which could paradoxically increase calorie intake and, over time, raise the risk of developing the very metabolic problems they are trying to prevent [1].
There is also the question of what to do with the information. A CGM that tells you your blood sugar spiked after a sandwich is not telling you what to do about it. The data, without a clear action plan, can become a source of anxiety rather than insight. The Mass General Brigham researchers specifically noted that for people without metabolic disease, CGM data does not replace the HbA1c test, which measures longer-term blood sugar control and is the standard clinical indicator [2]. That is a meaningful distinction.
What to Consider if You Are Thinking About Trying One
If you are a healthy person tempted by the promise of metabolic insights, a few things are worth weighing up front. The cost is real. CGMs can run several thousand dollars per year and are unlikely to be covered by insurance if you do not have diabetes [1]. The question you need to ask yourself is what you will actually do with the data, and whether that justifies the expense.
For people with a genuine interest in understanding their body's responses, perhaps as part of a structured nutrition or training plan, the monitor might offer genuine utility as a feedback tool. But it is worth approaching those insights with some humility about what they can and cannot tell you. The science here is genuinely evolving. The large-scale studies are relatively recent, and researchers themselves are still working out what all this variability means for long-term health outcomes.
The bottom line is this: for people with diabetes, CGMs are a genuine medical advance that improves quality of life and clinical outcomes. For everyone else, the jury is still very much out, and decisions to use these devices are personal calculations that should account for cost, realistic expectations, and a clear sense of what problem you are actually trying to solve.