ZOE diet: could this little device help you live for longer?

You’ve probably spotted someone wearing one in your Pilates class, those round patches cropping up on people’s arms. CGMs (or continuous glucose monitors) have become something of a status symbol among the fitterati. Think of them as a Fitbit for your metabolic health.

“Hacking your metabolism”, alongside glutathione IV drips and cryo chambers, are the latest wellness imports from Los Angeles, where the 0.1 per cent — think Gwyneth Paltrow, Orlando Bloom and Dave Asprey, the self-proclaimed father of biohacking — are obsessed with blood sugar control in their quest for eternal youth.

CGMs — disc-like gadgets worn under patches on the back of the arm — are typically used by people with diabetes to monitor blood sugar spikes and dips. But a new wave of health tech companies are marketing them to the wider population to offer yet another metric by which to track your wellbeing. Why the focus on blood sugar regulation if you don’t have diabetes? Being on a daily glucose rollercoaster, say, in response to certain carb-heavy or sugary foods, can mess with your sleep, energy levels and concentration, resulting in that 3pm slump many of us know all too well.

Longer-term, it creates extra work for your system and organs, contributing to inflammation and can speed up the rate of cell ageing, explains scientist and nutritionist Dr Federica Amati. To people like Asprey, who plan to live until 180, inflammation — which is linked to diseases like Alzheimer’s — is the enemy. So self-optimising to enhance mental and physical performance is the only way.

Zoe (joinzoe.com) is a personalised nutrition programme founded by Professor Tim Spector that’s focused on metabolic health — and it’s one of the most talked about in the UK since it launched here in Spring 2022. Before which, the £259.99 kit (for a test and results) had wracked up a 200,000- strong waiting list.

Unlike other companies, which solely focus on blood sugar response, it takes a more holistic approach to deliver a comprehensive snapshot of your metabolic health via a three-pronged attack.

Wear a CGM for two weeks; do a poop sample to discover what kind of bugs live in your gut; and take a finger prick test to see how you clear fats from your blood. Having high amounts of fat hanging around in your blood after meals is problematic for the vascular system, explains Dr Amati, who is also a lead nutritional coach for Zoe.

It then uses this data to teach you how to eat in sync with your metabolism. You could call it a form of biohacking to promote long-term health. Anecdotally, many people are crediting the Zoe test with overhauling their approach to food for the better.

Zoe points to interim data which suggests more than 80 per cent of members reported improved energy levels and feeling less hungry having undertaken the programme, and while it claims not to be about weight loss, it also reports users lost on average 4.3kg as a result of living more in tune with their biology.

Super-human energy levels and a laser-like focus sound good to me. Plus, lately, I’ve been experiencing uncomfortable perma-bloating, to the point where my jeans don’t fit. Something in my diet isn’t doing it for me. So I signed up.

It becomes strangely addictive checking the glucose sensor after each meal to see how I’m responding to different foods. One morning I see a huge spike after eating a slice of wholemeal toast and blueberry jam (it’s the sugar in the jam). Another day I see a major spike after a boxing class. High-intensity exercise, it turns out, can raise glucose levels, too. Our stress hormones tell the liver to tap into stored glycogen. However, this is a completely different physiological response to that of eating a pizza or slice of cake, I learn. It can actually improve glucose control and metabolic flexibility in the long-run.

At the end of the fortnight, I undergo a testing day during which I have to fast overnight before eating three extremely dry muffins which contain controlled amounts of carbs, fat, and protein for breakfast, followed by two more for lunch. The stool sample is relatively straightforward but the finger prick blood test feels like a year 9 biology experiment, and has to be carried out with precise timing.

It usually takes around six weeks to receive your Zoe results, but I find out later that my blood sample can’t be read so I have to repeat the muffin test (joy!) and get mine a few weeks later. Two detailed PDF reports contain separate scores for how I respond to carbs, fats and another assessing my gut health, all of which have been compared with others of my age and sex who have taken the test.

Hovering over the attachments, I feel weirdly nervous and start to mentally make a note of how many Five Guys I order in a month. There’s a history of Type 2 diabetes on one side of my family, so I’m surprised to find that my blood sugar control came back as 'good', meaning I’m less prone to large spikes after eating carb-rich foods. This, I’m told is rare. As did my blood fat response, suggesting I’m effective at clearing excess fat from my blood.

The area I need to work on is my gut health. There’s research to suggest that a healthy gut may help protect against metabolic diseases and even mental health issues. My gut diversity — or how many different microbes live in my gut — is 'poor', which on reflection doesn’t surprise me. I’m a creature of habit, often eating the same rotation of fruit and veg week-to-week.

One saving grace is that overall I have a higher ratio of “good” bacteria versus “bad” in my gut, which inches my score up. Along with the test kit, you also purchase the Zoe app (from £24.99/month) which is like having a personal nutritionist in your pocket.

There, I find a list of 100 different foods and a library of meal plans — from curries to Buddha bowls, one-pan pots to tray bakes that are packed with pulses and plant-sources that I don’t regularly eat — they’ve used a questionnaire I filled out on my diet to help put this together. Each food item and meal contains a unique score out of 100 for how “good” they are deemed for me and my metabolism using my test results. The higher the number, the better — so basically it’s the opposite of calorie counting.

My main takeaway from Zoe is to expand my food repertoire to improve my gut diversity. Aim for 30 plant sources a week, eat more fermented foods etc, which, admittedly, are conclusions I could have probably come to on my own. But with its endless meal-spo, Zoe makes this easy.

Given my apparent efficient glucose control, has it given me enough life-changing health insights to warrant the hefty price tag? I’m not so sure, but I did find the gut stuff fascinating. For others, who are more prone to blood sugar spikes, the app would probably feel more game-changing. It’s full of tips on how to flatten that curve, say, by combining carbs with protein and fats or simply changing the order you eat your food in.

There are so many experiments and “courses” on the app that teach you to form better food habits, but in all honesty, I didn’t have time to complete them all. But the more you feed it data, by logging your meals and energy levels afterwards, the more insight it gives.

If you’re the kind of person who geeks out on numbers and graphs then you’ll love it. With the Zoe app, you definitely get out what you put in.