Do People Without Diabetes Need to Monitor Their Blood Sugar?

It has never been easier to measure your blood sugar, and a growing number of businesses are eager to persuade you to use a continuous glucose monitor (CGM).

The CGM was originally designed for the management of diabetes, but many people without the condition have a genuine interest in their blood sugar levels, whether they’re concerned about their risk of chronic illness or driven to optimize their health or athletic performance.

At the moment, however, there is relatively little data demonstrating that CGM has benefits for people without diabetes, and experts differ on the wisdom of recommending the device to people outside the diabetes community.

A CGM is a small device that sticks to the body and measures the glucose levels in the interstitial fluid between your cells just below your skin, 24 hours per day, with a Bluetooth transmitter sending the data to your smartphone or a receiver. This sensor gives a complete picture of your blood sugar changes and patterns, sending data every 5 to 15 minutes, and users can easily see the effect of their food and exercise choices. Once only available with a prescription, CGMs are more accessible than ever now that the two leading manufacturers have released over-the-counter versions of their sensors.

“There are some people for whom seeing how the numbers change is a transformative experience,” says Jay Lusk, MD, a preventive medicine expert at the University of North Carolina School of Medicine in Chapel Hill. “They make a connection between their behaviors and this biomarker, and it changes everything for them.” He says that the unique benefit of CGMs is that they can “help patients take more agency over their health.”

Diana Isaacs, PharmD, CDCES, the director of education and training in diabetes technology at the Cleveland Clinic Endocrinology and Metabolism Institute, agrees. “It’s a lot different when I say to someone, ‘Hey, did you know that cereal can spike your glucose, and if you tried to eat a hard-boiled egg, it won’t spike your glucose as much?’ But there is something about experiencing that yourself that says, ‘Oh, I get that now, I am going to make a change.’”

This blood sugar feedback is considered extremely valuable for the optimal management of diabetes. It seems logical that the same kind of feedback could help people without diabetes keep their blood sugar under control, which could delay or reverse the progression of conditions like insulin resistance, prediabetes, and type 2 diabetes.

But so far, there is little data proving that it leads to improved health outcomes in people without diabetes. “There’s some theoretical promise there,” says Dr. Lusk, “but the data is very much still out on that question.”

David Ahn, MD, an endocrinologist at Hoag Urgent Care in Newport Beach, California, is skeptical that detailed CGM blood sugar data will be helpful to people without diabetes. “CGM is a really valuable tool to help people understand their relationship with food and their blood sugars,” he says, but it’s not at all optimized for people who don’t already experience unhealthy blood sugar swings.

Dr. Ahn says that CGMs tend to be more accurate when blood sugar is above or below the normal range. That’s a significant benefit for people with diabetes, but it means that “the accuracy and reliability of these biosensors is not necessarily appropriate” for people who do not experience hypoglycemia (low blood sugar) or hyperglycemia (high blood sugar).

“We shouldn’t be using these devices to diagnose diabetes. But certainly, if a person wears the device and sees that they’re constantly above 200 mg/dL, that will prompt them to go see their healthcare provider and get the proper testing,” she says. “Being able to uncover all the people walking around there who have prediabetes or undiagnosed type 2 diabetes — think about the implications for public health!”

• People with a family history of diabetes
• People who have prediabetes or additional risk factors, such as obesity or metabolic dysfunction–associated steatotic liver disease (MASLD)
• Women who have had gestational diabetes

Lusk is optimistic that CGM can make a difference, but the lack of scientific evidence makes him cautious. “This could be a really effective strategy,” he says. “The tough place for me is making that recommendation without concrete data about improved health outcomes. I believe that there are improved outcomes, but we don’t quite have that data yet.”

Today, Lusk does not recommend CGM technology to his patients without diabetes, but some of them have purchased sensors over the counter and have reported great results. “I wouldn’t be surprised if CGM use becomes common for diabetes prevention,” he says.

Intermittent CGM Use

“Someone can learn from their experiences, make changes, and then wear it again a month, two months, or three months later,” says Isaacs.

“I think intermittent use is a really good solution,” says Ahn. He also thinks that this usage pattern “will naturally end up happening,” because most users without diabetes won’t want to pay so much cash for continuous long-term use. Isaacs agrees. Intermittent use “would definitely be more cost-effective,” she says.

There is no real scientific support for the use of CGM in people without any personal or family history of metabolic illness. Ahn calls this an “evidence-free zone.”

“This is where I get concerned about over-the-counter CGM,” he says, “especially when they start marketing these devices toward the wellness community.”

Isaacs is more willing to encourage CGM use by healthy adults. “I really think that everyone can benefit from a CGM,” she says. “Regardless of who anyone is, CGM allows a person to see the direct impacts of physical activity, stress, sleep, and food choices on our glucose levels.” Even if blood sugar spikes are somewhat rare in this population, she believes they could lead to actionable data and healthier choices: “People can see, okay, what happened from this type of food? What was the glucose excursion? And how can it lead to healthier lifestyle changes by recognizing those patterns? … There’s still a lot of education here for the person without diabetes.”

“Think of the potential implications this could have on performance,” says Isaacs. “There’s a lot of promise here!”

• While continuous glucose monitors (CGMs) can offer insights into blood sugar responses, it’s not yet clear if they have real benefits for people without diabetes.
• In theory, CGMs could help people improve their metabolic health and even help prevent the development of type 2 diabetes, but scientific trials haven’t yet confirmed this benefit.
• Experts advise caution when using CGMs to avoid unnecessary stress or misinterpretation.
• CGMs cannot be used to diagnose prediabetes or diabetes. If you’re in doubt about your own metabolic health, please speak to a medical professional to ensure you get the appropriate evaluation and care.