Should you track your blood sugar? The surprising truth behind the trend

From wellness influencers to TV documentaries, blood sugar tracking is having a moment. These wearable devices, originally designed for people with diabetes, are now being used by the general public in the hope of “optimising” health and avoiding glucose spikes. But if your pancreas is doing its job just fine, is this trend really necessary — or is it another wellness distraction?

Let’s unpack what the science actually says.

Blood Sugar 101: What’s Going On Inside Your Body?

Before we dive in, here’s a quick refresher:

Blood sugar, or glucose, is your body’s preferred energy source. It comes from the carbohydrates in your food.

Insulin, the hormone made by your pancreas, moves glucose out of your blood and into your cells.

Your body taps into glucose stores when you’re exercising, fasting or need an energy boost.

For people with diabetes, where insulin function is impaired, managing blood sugar is crucial and can require medication, diet and lifestyle changes.

For people without diabetes, insulin works swiftly to bring any glucose spike back down, yes, even after sweets or a big pasta bowl.

Are Sugar Spikes Really That Bad?

Not all spikes are a cause for concern. Take a banana. It will raise your blood sugar, but it also delivers gut-loving fibre, potassium for your heart, and vitamin B6 for your brain. Compare that to a carb-free fried chicken thigh. Minimal glucose spike, but not much in the way of nutrients either. Which one is better for your health? The banana wins, every time.

Still, blood sugar monitors can prompt people to avoid foods that are actually good for them. In clinic, we see people skip porridge oats because of the glucose rise, unaware that oats are rich in beta-glucan; a type of fibre known to lower cholesterol. Others ditch watermelon due to its higher glycaemic index, even though it’s packed with skin-supporting lycopene and other powerful antioxidants.

The truth is, for people without diabetes, short-term spikes from nutritious foods are no big deal. Most of the negative claims around glucose levels come from studies in people with diabetes, where metabolism behaves quite differently.

Four Reasons to Reconsider Glucose Monitoring

If you don’t have diabetes or prediabetes, here’s why tracking every blood sugar rise might do more harm than good:

1. The data drama

Glucose naturally rises after eating; that’s normal. For people without diabetes, their body handles it quickly and efficiently.

2. Nutrient fallout

Skipping fibre-rich wholegrains and fruits to “keep it steady” could leave you low in essential nutrients and plant compounds that support everything from gut health to heart health.

3. Quality of life

A study of nearly 3000 Australians found that overly restrictive eating habits were linked to poorer quality of life. Cutting out carbs might seem “clean”, but it can take the joy out of eating.

4. The price tag

Continuous glucose monitors and their apps are expensive, and the science just isn’t there (yet) to support their benefits in people without diabetes.

It’s Not Just About What You Eat

Blood sugar levels can rise for lots of reasons that have nothing to do with food, and if you’re not aware of this, it’s easy to fall into the trap of blaming “bad” meals.

Stress

In one study, people who did a maths test before eating had higher blood sugar afterwards compared to when they ate the same meal in a relaxed state. Why? Cortisol (your stress hormone) can suppress insulin.

Sleep

A small study published in The Lancet showed that just six nights of restricted sleep led to impaired glucose regulation. Same meal, higher blood sugar after poor sleep.

What you ate yesterday

Yes, even your previous meal matters. One study showed that eating lentils at dinner led to lower blood sugar the next morning compared to a protein shake, even with the same breakfast.

Other factors like menstrual cycles, exercise, medications, and your gut microbiome all have an influence too.

A Smarter Way to Monitor Your Health

Instead of obsessing over glucose, turn your attention to your plant points. How many different plant-based foods can you eat in a week? Are you hitting all six Super Six plant groups: vegetables, fruit, wholegrains, legumes, nuts and seeds, herbs and spices?

This approach is not only more fun and flavourful, but research also shows it’s better for gut health, immunity, heart health and even mental wellbeing. Our team at King’s College London is currently studying this in a large clinical trial, and the early results are promising.

The Bottom Line

If you’re living with diabetes, blood sugar tracking can be life-saving. But for everyone else, it’s not the health hack it’s made out to be. Constantly chasing flat glucose lines can add stress, fuel restriction and lead to misguided food choices.

True health isn’t measured by a number on an app. It’s how you feel, how well your body functions, and whether your lifestyle supports long-term wellbeing. That starts with balance, variety and joy — not glucose paranoia.

So next time you reach for that banana or bowl of porridge, know that you’re nourishing your body and your microbes in all the right ways.

Resources

Ohio State University Wexner Medical Center. (2023). Study links stress with higher blood sugars. [online] Available at: https://medicine.osu.edu/news/study-links-stress-with-higher-blood-sugars [Accessed 1 Jun 2025].

Spiegel, K., Leproult, R. and Van Cauter, E. (1999). Impact of sleep debt on metabolic and endocrine function. The Lancet, 354(9188), pp.1435–1439. doi:10.1016/S0140-6736(99)01376-8.

Wolever, T.M.S. and Jenkins, D.J.A. (1986). The use of the glycemic index in predicting the blood glucose response to mixed meals. American Journal of Clinical Nutrition, 43(1), pp.167–172.

(Also see: Thomast, W. et al. (2011). The subsequent meal effect of lentils. ResearchGate. Available at: https://www.researchgate.net/figure/Subsequent-meal-effect-of-whole-grains-and-lentils_tbl1_51844740 [Accessed 1 Jun 2025].)

King’s College London. (2023). Researchers receive £1.5m grant to investigate impact of plant food diversity on health. [online] Available at: https://www.kcl.ac.uk/news/researchers-receive-1.5m-grant-to-investigate-impact-of-plant-food-diversity-on-health

European Food Safety Authority (EFSA). (2010). Scientific Opinion on the substantiation of health claims related to beta-glucans from oats and barley. EFSA Journal, 8(12), p.1885. doi:10.2903/j.efsa.2010.1885.