Should You Use a Continuous Glucose Monitor If You Don’t Have Diabetes?

Blood Glucose Spikes ARE NOT Inherently Bad!

Blood glucose levels are an important marker of metabolic health, but they’re not the whole story for many.

For people with diabetes, tracking glucose closely is essential and often life-saving, but in non-diabetic individuals, the benefit is less clear. Managing metabolic and endocrine health requires a comprehensive approach that considers nutrition, physical activity, sleep, stress, hormones, and genetics. Glucose data can offer some insights, but focusing too narrowly on it might result in individuals and clinicians missing the bigger picture.

That’s why the recent surge in popularity of continuous glucose monitors (CGMs) among people without diabetes raises important questions. These tools are widely marketed to wellness-conscious individuals looking to optimise energy, performance, or longevity. But how useful are these devices for people without a medical reason to monitor glucose, and could they be doing more harm than good?

What Are Continuous Glucose Monitors?

CGMs measure glucose levels in the interstitial fluid, the fluid between cells just beneath the skin. A small sensor is inserted, typically in the upper arm or abdomen, and transmits glucose readings every few minutes to a smartphone or connected device. This provides a real-time picture of glucose trends in response to food, exercise, stress, sleep, and illness.

For people with diabetes, CGMs can be life-changing. They support improved glycaemic control, reduce the risk of hypoglycaemia (low blood sugar), and help prevent long-term complications. CGMs are also being explored in other areas of health, including prediabetes prevention, managing gestational diabetes, and preventing migraines.

When used in those at elevated risk of, or with a diagnosed condition like diabetes, prediabetes, or gestational diabetes, CGMs can provide meaningful data to support clinical decisions.

Does That Mean Everyone Should Track Their Glucose?

Not necessarily. Some studies suggest that seeing glucose feedback may encourage healthier habits, such as more physical activity or improved food choices. However, a recent review found only small improvements in glucose control in people without diabetes. The benefits, if any, appear to be short-term and highly individual.

It’s important to understand that a rise in blood glucose after eating is completely normal. It is part of how the body processes food. While CGMs can provide insight into personal responses to meals, sleep, or stress, the long-term benefits of tracking glucose in healthy individuals remain unclear.

An individual’s glucose response to the same food can vary from day to day. Consequently, seeing a sharp rise in response to a particular food on just one occasion doesn’t necessarily indicate a problem. In fact, it could lead to avoiding nutritious foods such as oats, fruit, or wholegrain bread based on an inaccurate or incomplete snapshot.

Using Continuous Glucose Monitors If You Have Polycystic Ovary Syndrome

Polycystic Ovary Syndrome (PCOS) is a common hormonal condition often linked to insulin resistance and a higher risk of metabolic complications.

While CGMs may offer useful insights for some women with PCOS, they are not yet a standard part of care. Research into their potential role in this population is still ongoing.

If you have PCOS and are considering using a CGM, it’s important to speak with your healthcare provider or a registered dietitian. They can help you interpret the data accurately and ensure it supports your overall health rather than causing confusion or unnecessary dietary changes.

How Accurate Are the Readings?

While CGMs are clinically validated for diabetes care, they’re not perfect, and their accuracy can be even less reliable in people without diabetes. Several factors can affect how well they reflect what’s actually happening in your body:

• Glucose lag: CGMs measure interstitial fluid, not blood directly. This causes a natural delay of about 5 to 10 minutes during rapid blood glucose changes, such as after eating or exercising.

• Sensor variability: Studies have found that two CGMs worn by the same person can show different blood glucose readings at the same time.

• Sensor accuracy: Glucose readings reported by CGMs can be 8-10% above or below your blood’s actual glucose level. While acceptable in clinical settings, this is a notable margin for self-optimisation.

Glucorexia

One emerging concern associated with CGM use is “glucorexia”, the anxiety and overcorrection that can arise from obsessively monitoring glucose.

Influencers and wellness marketers often push the idea that glucose should never spike, encouraging unnecessary carb restriction or extreme diets based on a limited understanding of glucose physiology. But not all spikes are bad. In fact, a moderate rise in glucose after eating is entirely normal and expected.

This kind of rigid approach is not just unhelpful but potentially harmful, especially without professional guidance. Misinterpreting glucose trends may lead to food fears, disordered eating patterns, or unnecessary restriction that undermines overall health.

Final Thoughts

CGMs may support short-term self-experimentation, helping you spot general trends in your glucose response to meals, sleep, or workouts. This can be empowering, but only if the data is interpreted with care, in the correct context, and under professional guidance. However, for most, CGMs are not a necessary tool for health or performance. The data can be inconsistent, the sensors are expensive, need regular replacement, and require a compatible smartphone to function.

Before investing in a CGM, it is worth asking:

• What do I hope to learn?

• Do I have the support to interpret the data meaningfully?

• Might this distract me from the bigger picture?

If you're concerned about your blood sugar or metabolic health, speaking to a GP or registered dietitian is a far better place to start than self-tracking every fluctuation. For most people, the foundations of long-term health are still the same: balanced nutrition, regular movement, restorative sleep, and effective stress management. No sensor required.

Need expert guidance to improve your health? As a registered dietitian, I offer personalised support to help you make evidence-based changes that align with your lifestyle, and long-term health goals. Book Now.

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