How glucose trackers became a status symbol

For the past few years, interest in technology which monitors our health has soared. In 2022, the global digital health market was valued at over 330 billion dollars, and according to recent forecasts, this figure is expected to exceed 650 billion by 2025. Today, 46 per cent of UK adults say they use health-monitoring technology, such as an Apple Watch or Fitbit.

Continuous glucose monitors (CGMs) have recently become a particularly sought-after piece of health tech. Historically, CGMs have been used almost exclusively by diabetics to monitor blood sugar levels, but now growing numbers of people without diabetes have begun using them: from former Love Island contestants to biohacking-obsessed tech bros like Bryan Johnson. The trend has taken off partly as a number of fitness programmes such as HelloLingo, Signos, Veri, and The Better Nutrition Programme have cropped up in recent years, all of which provide users with a CGM to monitor their glucose levels.

The most popular of these programmes is doubtless ZOE, a “personalised nutrition service” co-founded by Tim Spector, a genetic epidemiologist at King’s College London. It doesn’t come cheap: the £299 ZOE starter pack includes a faecal sampling kit, a finger-prick blood test, and a CGM, but you also need to fork out £24.99 every month for the membership fee. At present, ZOE has amassed 130,000 subscribers and over half a million followers on Instagram.

ZOE is marketed as a science-backed programme more concerned with good health as opposed to weight loss, a distinction which doubtless curries favour with modern, socially-conscious consumers. “We don’t tell you what you can and can’t eat. And we don’t count calories. Instead, we teach you how to add different foods to your meals to improve your body’s response,” their website reads. On the surface, it sounds like a balm against years of diet culture which encouraged disordered eating.

But while ZOE doesn’t tell users to entirely forgo indulgent food or encourage counting calories, it does ‘score’ foods based on how much they will spike your blood sugar – and as users wear glucose monitors, they can see the impact of their choices in real time. “Through testing, you may find that some of your favourite healthy snacks and meals are having a negative effect on your body,” they say. “For example, we’ve found that bananas cause large blood sugar spikes for 25 per cent of adults, which is linked to energy slumps and hunger pangs.”

While it is true that bananas can cause your blood sugar levels to rise, it’s unclear why this matters. If you’re not diabetic, your pancreas produces the hormone insulin which naturally regulates blood sugar levels. The reason why people with diabetes monitor their blood sugar levels is because their bodies might not produce enough insulin, meaning their blood sugar levels are prone to crashing and spiking more dramatically. Wearing a CGM can help them work out when to take more medication or when to eat in order to avoid their blood sugar levels rising or falling to dangerous levels.

Nicola Guess, a dietitian and researcher at the University of Oxford, tells Dazed that while it isn’t inherently problematic for non-diabetic people to use CGMs, there “probably is no need” for people who are at no risk of developing diabetes to track their blood sugar levels. “The truth is, we don’t actually know in practice what any of the peaks and dips mean in a person without diabetes,” she explains. “Glucose is a miniscule, possibly even negligible, part of health in people without diabetes [...] I worry we are scaremongering people into thinking every meal has to be a scientific experiment.”

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It’s easy to see how using a CGM can become a gateway to adopting an unhealthy, restrictive attitude towards food in people who have no medical reason to track their blood sugar levels. Chloe Gray is a freelance writer and fitness instructor who tried ZOE back in 2022; she tells Dazed that while she found the experience “interesting”, she is sceptical about whether it’s healthy for people to have access to so much data about their bodies. “I’m always very curious to try out new things and learn about my body, though I did think wearing a medical device was maybe a bit far,” she says, adding that ZOE’s analysis concluded that her blood sugar control was ‘poor’.

Though she stresses that her overall experience of ZOE was “pretty positive”, Gray decided against continuing with the programme long-term and quit after a couple of weeks. “I have my own history of disordered eating and honestly just can’t be arsed to spend my time logging food into an app,” she says. “I do think that other people might get too obsessed with it [...] It’s very easy to see how people would demonise ‘red’ foods [which spike blood sugar] rather than use it to show we can eat balanced plates.”

Dr Rachael Kent is a lecturer at King’s College London, author, and host of the Digital Health Diagnosed podcast. “The surge in health tracking via apps and wearables has been steadily increasing since 2010 and now today many of us track many aspects of our health, mood and everyday lives for personal insight, self-motivation and to keep ourselves accountable,” she says, explaining that health tech offers us unprecedented insight into “our personal capacities on a fitness level, the steps we take, the food we consume and now with the rise of continuous blood-glucose monitors our blood sugar levels.”

“I worry we are scaremongering people into thinking every meal has to be a scientific experiment” – Nicola Guess

In the midst of the indomitable rise of health tech, it’s worth pausing to ask: what is this all for? Is this much knowledge about our bodies really necessary? Dr Kent doesn’t think so, and goes as far as suggesting that using a CGM could even have adverse health effects on people who don’t need to monitor their blood sugar levels. “My research and others’ is showing that such accumulation of data and compulsive or addictive self-monitoring can cause a huge amount of stress for those who are well and not suffering from a chronic condition or disease,” she says, adding that obsessive tracking can lead to good health becoming perceived as something to be achieved through “hyper self-surveillance, increasing responsibility of the individual tracker, leading over time to stress, guilt and anxiety in everyday life.” Gray agrees. “When we tell people that we all need to worry about what our individual bodies are doing, it becomes dangerous, obsessive and anxiety-inducing,” she adds.

A quick glimpse at posts within a Facebook group for ZOE users clearly shows that these fears are not unfounded. One person posts about how much they miss eating biscuits; users in the comments urge them to stay strong and keep going. Another appears horrified that a friend could possibly eat “macaroni cheese with ham, mangetout and tenderstem broccoli” for dinner. No one in the group seems to think this is a worrying thing to say. People take pride in obsessively logging everything they eat: every slice of toast, every clove of garlic, every pinch of salt. There are alarming similarities between the online community of CGM users and pro-ana forums, with many of these users exhibiting characteristics of orthorexia too.

Status symbols are a great bellwether for gauging the flavour of an era’s zeitgeist. In the 17th century, for example, the moneyed classes would seek out pineapples to use as centrepieces at dinner parties, as the expense of importing them from the ‘New World’ rendered them exotic, colonial-era icons of luxury. So with this in mind, what does our obsession with CGMs and health tech more broadly say about 21st century life? It suggests that society is growing increasingly individualistic. That your health is seen as entirely your responsibility. That good health is now a privilege, and the pursuit of good health a pastime for the rich (as you might have gleaned from ZOE’s hefty price tag). People are increasingly expected and encouraged to fend for themselves as institutions like the NHS are decimated. As James Greig writes in Vittles, “in the absence of a secure safety net, a neurotic fixation on one’s health is understandable”. 

But while it’s understandable, it’s certainly not helpful, healthy, or necessary. “These trackers encourage us to adopt a medical lens [...] to look inside our bodies in a way that was once reserved only for clinicians or those with certain qualifications and expertise,” Dr Kent says, adding that “this places a huge amount of pressure on individual consumers to not only understand what their data is telling them, but to also to interpret it accurately.” Gray agrees that in-depth analysis is best left to the professionals – and only necessary for people who actually have health issues. “No one needs information to be that personal. Most people, with obvious exceptions like people with medical conditions, require pretty much the same framework: eating plants, making sure all meals have balanced macronutrients,” she says. In other words: try to eat a balance of vegetables, carbohydrates, fats, and protein. Try to move around as much as possible. Try to get enough sleep. If you don’t have any underlying medical conditions, your body will do the rest. You don’t need to buy an expensive CGM to know that.