Continuous Blood Sugar Monitoring: Is it Right for You?

Some individuals will try anything once in pursuit of weight loss or improved health. While there's no harm in trying new things, often times these fad-based endeavors lack the test results that give them credibility. Recently, a new trend to use a continuous glucose monitor to keep track of blood sugar levels—for people who don't have diabetes—added itself to the wellness space's trend roster.

This concept is touted as a way to help you figure out how your blood sugar responds to different foods and lifestyle impacts, such as exercise, sleep, and stress. But does this tactic really lead to weight loss or improved health, or is it just a fad with no scientific merit? Let's find out.

What Is Continuous Blood Sugar Monitoring?

A continuous glucose monitor (CGM) is a wearable device that tracks blood sugar levels. It includes a transmitter and a small disposable sensor that is worn under the skin. Rather than using finger pricks to test blood glucose at intervals throughout the day, the CGM tracks blood sugar every few minutes throughout the day and night and shares the electronic readings in real-time.

Continuous glucose monitor (CGM) systems were originally intended to help people with type 1 or type 2 diabetes monitor their blood sugar levels more consistently. It can be a lifesaver for people who experience low blood sugar levels at night, which comes with the risk of not waking the next morning.

In the past few years, there's also been interest in monitoring blood sugar for other diseases, and also for general health and wellness. New uses for CGM are becoming popular and more companies are marketing CGM for use beyond diabetes.

Benefits of Continuous Blood Sugar Monitoring

Most of the research on CGMs involves their efficacy for people with type 1 or type 2 diabetes, where they are found to be very useful. There's less research on the use of CGMs in non-diabetes populations.

"CGMs may be able to help detect the onset of diabetes or prediabetes," says Jessica DeGore RD LDN CDE CHWC, a dietitian and nutrition coach for people with diabetes. DeGore explains that approximately 96 million American adults have prediabetes and more than 80% don’t know they have it. A CGM could help with earlier detection and disease management, which may be beneficial. 

Some studies show benefits for the use of CGMs (in the absence of diabetes) in these specific healthcare situations:

• People with end-stage renal disease may use CGMs during hemodialysis, where changes in blood sugar concentrations can help guide treatment.
• Children with epilepsy who are treated with a ketogenic diet may wear CGMs to monitor blood glucose levels to help manage the diet.
• People who have undergone a kidney transplant may experience high blood sugar. A CGM can monitor blood sugar and flag patients at risk for post-transplant diabetes and graft failure.

"CGMs may also be used in preterm babies, people with polycystic ovary syndrome, and critically ill hospital patients to reduce hypoglycemia, insulin resistance, glycemic variability, and length of hospital stays," says Amanda Ciprich, MS, RD, a dietitian who works with people with type 1 diabetes.

So there are some clinically-supported reasons beyond diabetes why a CGM may be worn. But what about using CGM as a trendy way to track your own health, the way some people count their macros or their daily steps?

CGMs and Lifestyle Management

Despite little research to support it, social media influencers, fitness enthusiasts, and 'biohackers' are interested in using CGMs for off-market use—as a way to manage their food intake or weight.

"Most people who wear a CGM without a diabetes diagnosis are using them as a way to dictate eating patterns, typically for weight loss," says DeGore. "I’ve heard anecdotally that people have been able to make healthier choices by bringing awareness to how food affects their blood sugar."

DeGore adds that it should be understood that blood sugar levels can be affected by more than just food. It is also affected by exercise level, hydration status, sleep, illness, stress, and caffeine intake—even a sunburn can affect blood sugar. It may be difficult to tease out why blood sugar changes, so a healthcare provider should be involved to help interpret results.

Do CGMs help with weight loss? Rabiya Bower, MHSc, RDN, LDN, coordinator of the nutrition program at Thomas Jefferson University, explains that a CGM will show which foods spike blood sugar, and in that state, some bodies may store the extra energy as weight.

"Despite having a working pancreas to produce insulin, certain foods will increase blood sugar in healthy individuals," says Bower. "By eliminating or reducing intake of those specific foods, people might lose weight."

Despite this working theory, a search of clinical research on the use of CGMs for weight loss in non-diabetes populations yields zero studies on this topic. Without any research, it's impossible to say if CGMs help with weight control.

Finally, one small study shared the results of providing sedentary people (without diabetes) with a CGM and an activity tracker for 10 days. They reported feeling more motivated to exercise. If people note a blood sugar spike after a particular meal, they may eat those foods less often, or be motivated to take a post-meal walk.

Risks of Continuous Blood Sugar Monitoring

The device itself is low risk and comes with few complications, but getting too fixated on the results is a big red flag.

"Wearing a CGM without medical necessity is not shown to provide substantial benefits and could possibly be dangerous," explains DeGore. "It’s another form of tracking to make decisions about what foods to eat or not eat. I can see it leading very easily to disordered eating behaviors such as obsessing about food and restrictive eating."

One study that was conducted as a baseline to establish reference sensor glucose ranges found that among people who don't have diabetes, about 96% of the time blood sugar levels were normal or nearly so, and outlier sugar values were deemed implausible or a mistake. So, most of the time, the results will show very little.

Beyond health risks, it's also important to consider the societal impact, ethics of access, and the cost of CGMs.

"There are approximately 2 million adults with diabetes who are not insured, and therefore are very unlikely to have access to this potentially life-saving technology," says Bower, who, as a person with diabetes, says the CGM has saved her life. "I would rather see CGMs be distributed and used by people with diabetes than by people without this chronic disease."

Bower adds that diabetes is an exhausting, expensive, and consuming disease. "I've had it for over 25 years, and I don't get a single day off from it. To see someone wearing a CGM "just for fun" or as an
experiment, feels like a mockery to me, whether or not that is their intention."

Ciprich notes that while being able to see blood glucose values in-real time could potentially detect an earlier diagnosis of prediabetes, the use of CGMs for prediabetes detection could be incredibly costly.

"More cost-effective ways to detect prediabetes could be getting annual blood work, which many people skip out on, or using a glucose meter to track fasting blood glucose levels," says Ciprich.  

When to See a Healthcare Provider

If you have type 1 or type 2 diabetes, talk to your doctor about CGMs. In absence of diabetes, there may be other clinical reasons why a CGM would be helpful, such as if you have prediabetes, PCOS, or renal disease. Your healthcare provider can guide you accordingly.

Note that CGMs are only available with a prescription, so any decisions about wearing one will have to be discussed with your doctor.

A Word From Verywell

CGMs are seen as lifesaving devices for people with diabetes, and there are a few other clinical conditions where monitoring blood sugar levels may be beneficial. There's still little research on whether wearing a CGM can help with long-term weight management, and the cost of CGMs is prohibitive for many.

Until more studies can show the value of CGM as a "lifestyle choice" for people who don't have diabetes, there's little evidence to support this use. That won't stop CGM makers from marketing this technology to people without diabetes as a way to improve their health.