Keeping a close eye on your blood glucose levels is part and parcel of life for people living with diabetes. The last few years, however, have seen a sharp rise in health-conscious people without the condition wanting to monitor their blood sugar, too – but is there actually a need to?
How are people tracking their blood sugar?
One of the most popular ways people are monitoring their glucose levels is with a wearable type of device called a continuous glucose monitor (CGM), which often looks like a white disc placed on the upper arm.
CGMs don’t actually directly monitor blood glucose. Instead, they use a sensor to measure the glucose in the fluid that surrounds the cells underneath the skin, known as interstitial fluid. Glucose from the blood moves into this fluid on its way to cells, and so it is generally considered to be at a similar level to that in the blood.
Sensors typically take a measurement every few minutes, which is then sent to some sort of receiver – this might be an insulin pump for someone with diabetes, or a smartphone app.
People with diabetes have been using such devices for years, but last year, the Food and Drug Administration (FDA) cleared the first-ever over-the-counter CGM for marketing. It was cleared for people with diabetes who don’t use insulin, but also for “those without diabetes who want to better understand how diet and exercise may impact blood sugar levels.”
That means anyone can get a hold of one, for a price; these devices aren’t exactly cheap, and some estimates have put the global market value of CGMs at a hefty – and growing – $9.3 billion.
Does it have any benefit?
The overwhelming consensus amongst scientists is that there’s very little evidence to suggest that tracking your blood glucose levels has any benefit if you’ve not got diabetes, or other rare conditions affecting blood sugar that would need to be confirmed by a doctor.
A 2024 review of research on the use of CGMs in people without diabetes to detect abnormal glucose levels and stimulate behavioral changes and improvements in metabolic health found “a lack of consistent and high-quality evidence to support the utility of CGMs for these purposes.”
That’s not to say there isn’t a chance that, with better research, CGMs might end up proving to be useful to people without diabetes in some way. For instance, one 2023 article argued that endurance athletes may uniquely benefit from monitoring of blood glucose as part of their training, as there’s some evidence to suggest they have physiological responses that “challenge our understanding of glucose regulation.” The authors of that paper say more research is needed to know for sure.
And at present, the evidence simply isn’t compelling enough for the vast majority of us – despite how it’s being presented by some.
The authors of the review point out that companies selling CGMs often claim their products are useful for detecting things like abnormal glucose levels, despite not being backed up by science. “In the face of these research gaps, we urge for the commercial claims suggesting the utility of the device in [people not living with diabetes] to be labelled as misleading,” the review authors write.
Attempts to fill in the gaps in the research also haven’t strengthened the case for tracking blood glucose levels in people who don’t have diabetes. A 2025 study conducted by researchers at the University of Bath found that, when comparing glucose measurements of healthy individuals taken by CGMs and with the gold-standard “finger prick” test, CGMs frequently overestimated blood sugar levels.
These differences “can be significant in those who are healthy and have normal blood glucose control, as their normal range of blood glucose is typically far smaller,” Dr Adam Collins, associate professor of nutrition at the University of Surrey, said in a comment for the Science Media Centre. Collins wasn’t involved in the study, but has been carrying out similar research that has made similar findings.
“This can lead to misinterpretation and ‘misdiagnosis’ of apparent blood glucose excursions that still remain within the boundaries of normal,” Collins added. “Indeed, often individuals are basing dietary and lifestyle changes on what are essentially variations of normal anyway, compounded by a magnitude of error in the data itself.”
Does it do any harm?
Keeping those inaccuracies in mind, there’s a concern amongst some that continuously monitoring glucose levels could end up doing more harm than good in people who don’t have diabetes.
One worry, for example, is that it runs the risk of people overmedicalizing something that’s actually perfectly normal.
“I think there are downsides to having too much data,” NYU Langone endocrinologist Dr Michael B. Natter told Yahoo Life. “When we see a small spike after a meal, that could actually be very normal. I fear that might be overinterpreted and misread as pathologic or bad.”
This could manifest itself in things like increased health anxiety and trips to the doctor, or unwarranted changes in someone’s eating habits.
“For healthy individuals, relying on CGMs could lead to unnecessary food restrictions or poor dietary choices,” explained Professor Javier Gonzalez, one of the authors of the CGM accuracy study, in a statement.
This isn’t an unfounded worry; regular use of other tech that allows people to monitor health-related data like calorie intake and measures of fitness has been linked by some research to eating disorder attitudes and behaviors.
The bottom line? “The use and interpretation of CGM devices in healthy individuals should be undertaken with caution. They certainly shouldn’t be used as the sole basis for dietary changes, restrictions, or extreme lifestyle changes,” said Collins.
If someone is concerned about their blood sugar levels, or any other health-related matter, then the best course of action is to speak to a healthcare professional.
All “explainer” articles are confirmed by fact checkers to be correct at time of publishing. Text, images, and links may be edited, removed, or added to at a later date to keep information current.
The content of this article is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of qualified health providers with questions you may have regarding medical conditions.
If you or someone you know might have an eating disorder, help and support are available in the US at nationaleatingdisorders.org. In the UK, help and support are available at beateatingdisorders.org.uk. International helplines can be found at https://www.worldeatingdisordersday.org/home/find-help.
