Do You Need a CGM (Non-Diabetic)?
CGMs can be a useful tool for understanding how the body responds to food. The key is knowing how to read the numbers, and when they need more context.
Written by Anne Wilfong RDN, LD, CEDS
A number pops up on the app after a meal. It's higher than expected. And then the questions start: Did you eat the wrong thing? Is something wrong with your blood sugar? That reaction is understandable. A 2025 study found that more than two-thirds of CGM users reported feeling afraid when they saw a high glucose reading, whether or not they had diabetes. But more data doesn't automatically mean better health. One glucose reading isn't a report card on food, the body, or overall health. Continuous glucose monitors (CGMs) can be incredibly useful tools. The question is whether they're useful for a particular person and what will actually be done with all those numbers.
Is a glucose spike automatically a problem?
No. Blood glucose is supposed to change. It rises after eating and then comes back down as the body uses and stores glucose. Food is only one factor. Exercise, stress, sleep, illness, hormones, medications, and even the time of day can affect glucose levels. So a rise after breakfast doesn't automatically mean the "wrong" breakfast was eaten. This is where CGM apps can get confusing. An app may label a reading as "high" or "out of range," but that doesn't make it a diagnosis. A single reading doesn't tell the whole story. What matters more is the bigger picture and whether there is a consistent pattern that actually needs attention.
Who does a CGM actually help?
For people with diabetes, CGMs are an important part of diabetes management. They provide information about glucose patterns throughout the day that occasional fingerstick testing can't capture. Wilfong Nutrition's Type 2 Diabetes Care can help with the nutrition side of diabetes care.
There is also growing research on CGM use in people with prediabetes. Some studies have found improvements in measures such as HbA1c or time spent in a target glucose range. However, that doesn't mean everyone with prediabetes needs a CGM. Whether it is useful depends on the individual and how the information will be used.
For people with normal glucose levels who are wearing a CGM simply out of curiosity, the evidence is much less clear. Researchers are studying whether certain glucose patterns may be associated with future health risks. That's different from showing that wearing a CGM actually prevents diabetes or improves health in people who don't have it.
Right now, there isn't strong evidence that people with normal glucose levels become healthier simply by wearing a CGM and changing their food based on the numbers.
What about CGMs and GLP-1 medications?
For people taking a GLP-1 medication and also managing diabetes, a CGM may be useful. It can provide healthcare providers with information about glucose patterns and help inform treatment decisions.
For people with prediabetes, whether a CGM would be helpful is more individualized.
For those with normal glucose levels, a simpler question comes first:
What would actually change, in a lasting way, based on the information from the CGM? Not every available health metric needs to be tracked. Wilfong Nutrition's GLP-1 Nutrition Counseling can help people navigate nutrition while taking these medications without adding another layer of rules around food.
Are CGMs accurate?
Today's consumer CGMs, including Stelo and Lingo, use similar sensor technology to prescription devices such as the Dexcom G7 and FreeStyle Libre systems. They're reasonably accurate, but they're not perfect. CGMs measure glucose in interstitial fluid rather than directly measuring blood glucose, and differences can be more noticeable when glucose is changing quickly. But accuracy isn't really the only question. A number can be accurate and still be misunderstood. A CGM can show what glucose is doing. It can't, by itself, determine whether someone's diet needs to change.
Can a CGM contribute to food anxiety or disordered eating?
This is the part of the CGM conversation that deserves more attention. The fear response to a high reading isn't unusual, and people with a history of disordered eating may be particularly vulnerable to becoming distressed by glucose data. It's easy to see how the cycle can begin.
A glucose spike after breakfast leads to guilt.
That food gets labeled "bad."
Carbohydrates start getting restricted.
One meal gets compared with another.
Eventually, the CGM is being checked after every meal to see whether the person "did well."
Eating starts to feel like a test that can be passed or failed. That's not what nutrition is supposed to do.
If using a CGM is making someone more anxious about food, avoiding certain foods, restricting carbohydrates, or feeling like glucose needs to be "fixed," that's important information. It may be a sign that the device isn't helping. People with a history of an eating disorder or disordered eating should talk with their treatment team before using a CGM for "metabolic health" purposes. Wilfong Nutrition's Eating Disorder Care focuses on helping clients nourish their bodies without turning food into another set of rules. For more on the intersection of GLP-1 medications and disordered eating, see GLP-1 Medications and Disordered Eating.
Should someone wear a CGM?
There isn't one right answer.
For someone with diabetes, a CGM can be an important medical tool. With prediabetes, it may be useful in some situations.
For someone with normal glucose levels who is considering one because of interest in "metabolic health," a few questions can help clarify that:
What's the goal?
What question is the CGM supposed to answer?
What would actually change based on the information?
Could the numbers create more anxiety around food?
That last question matters. Blood glucose is supposed to move. It doesn't need to stay perfectly flat. And eating isn't a test that can be passed or failed. That's one of the principles at the heart of intuitive eating.
The bottom line
CGMs are valuable tools for diabetes and may be useful in some situations involving prediabetes. For people with normal glucose levels, however, wearing a CGM simply because it's available doesn't necessarily improve health. If the numbers are making someone more anxious about food or more restrictive with eating, that's something to pay attention to. The goal isn't perfectly flat glucose graphs. It's nourishing the body and supporting health without making eating harder than it needs to be. Anyone unsure whether a CGM makes sense for their situation, or what the numbers actually mean, can work with a registered dietitian to look at the bigger picture rather than reacting to each number as it appears.
Schedule a consultation with the Wilfong Nutrition team.
Frequently Asked Questions
What is normal blood sugar after eating?
Blood glucose normally rises after eating, including in people who don't have diabetes. The size and timing of that rise can vary based on the meal, activity, stress, sleep, hormones, medications, and other factors. A CGM reading that looks "high" to an app doesn't automatically mean something is wrong.
Can someone wear a CGM if they don't have diabetes?
Yes. Some CGMs are available directly to consumers without a prescription. Before using one, it helps to consider what the person hopes to learn and whether the information will actually be useful.
Are CGMs accurate for people without diabetes?
CGMs provide reasonably accurate information, but they're not perfect. They measure glucose in interstitial fluid rather than directly measuring blood glucose, and readings can differ somewhat from blood glucose measurements.
Can using a CGM contribute to disordered eating?
For some people, yes. A high reading can lead to anxiety about food, restriction, or a desire to "fix" normal glucose changes. Avoiding foods, restricting carbohydrates, feeling guilty after meals, or constantly checking a CGM are signs that it may be time to talk with a healthcare team.
Should someone get a CGM if they're taking a GLP-1 medication?
It depends on their health history. For people with diabetes, a CGM may provide useful information for their healthcare team. For people with normal glucose levels, the more useful question is whether the information would actually change treatment.
