Zoe has around 130,000 subscribers and has 597,000 followers on the social media platform Instagram.
The CGM is similar to that diabetics use to monitor their blood sugar levels. You wear it for two weeks to get a good cross-section of results, which the Zoe app then uses to recommend certain foods that will give you fewer blood sugar spikes.
The aim is to gain insights to help you stabilize your blood sugar and fat levels and boost your gut bacteria, which Zoe believes is the key to achieving a healthy weight and improving long-term health.
A large spike in glucose in the blood causes a large spike in the body's own insulin production, which blocks fat burning and stimulates fat storage, according to Zoe.
Reducing glucose peaks too helps reduce inflammation, conserve energy and control hunger. This reduces the risk of diabetes and heart disease.
Zoe tests your bacterial composition intestine via a stool sample, and your metabolism by having you eat a blue-dyed cookie and recording how long it takes to pass through your intestines.
Zoe is an investment: it costs £270 (US$340) upfront, including the gut microbiome test, blood sugar and blood fat tests, biscuits and a blood sugar meter.
In addition to the test kit, you will also need to purchase a subscription to the Zoe app, which costs £45 per month.
I paid for the kit in August 2023, but it was out of stock so I was put on a waiting list and finally received it last October.
The contents are supplied in individual, clearly labeled yellow boxes. You first download the app. This is simple and gives clear advice on attaching the CGM to your arm.
I couldn't bring myself to press the button to stick the needle in my arm, so I asked my husband to do it. He ended up bending the needle. The company sent a new one within two days.
I put the new CGM on my arm myself; the needle went in and didn't hurt at all. I immediately started tracking my blood sugar levels and could tell when mine was in range, peaking or falling.
Checking your blood sugar becomes bizarrely addictive, and I found myself checking mine throughout the day to see how I reacted to different food combinations.
I was surprised by the ways my blood glucose levels could be raised, such as eating a baked sweet potato with butter and olive oil, or a green apple.
I also experience a spike on an empty stomach - intense exercise increases glucose levels because our cortisol triggers the liver to release stored glycogen - although those types of spikes are not considered harmful.
Why should we worry about what our blood sugar levels are doing? There is some evidence that extreme glucose spikes can cause inflammation over time and increase the risk of it heart disease And Type 2 diabetes.
On Zoë's first day of testing, you eat two cookies for breakfast and two more for lunch. The breakfast biscuits are thick and rusk-like, with chunks of white chocolate - and contain more than 600 calories. I am surprised to see that they contain palm oil.
My blood sugar levels are spiking, although not outside the target range.
The lunch biscuits are colored bright royal blue, so that you can understand the transit time in your intestines when you poop blue. Zoe's research shows that intestinal transit time is an important indicator of gut health, with shorter times generally associated with better health.
I kept waiting for my blue poop, but I never saw it. Zoe says many users never see blue poop; sometimes the intestine breaks down the dye.
After eating the cookies you take a blood test, which requires a small, self-made scratch on a finger to get a drop of blood.
Then comes the poop sample, which you send in a addressed envelope together with the blood sample.
During the fourteen days you have to wear the tracker, Zoe asks you to do daily 'experiments' to see how your body reacts. For example, eat pure carbohydrates for breakfast one morning (I chose oatmeal porridge and water) and pure fats the next day (I chose an avocado) and then a combination of fats and carbohydrates (I had a handful of almonds and porridge).
Zoe suggests exercising before breakfast one morning, and exercising after eating a fat and carbohydrate breakfast on another day. Zoe is all about 'flattening the curve' - that is, keeping your blood sugar spikes to a minimum.
I've long been a no-breakfast person, but my blood sugar levels were much flatter when I ate a mix of carbs and fat before exercise.
One habit I've kept up since trying Zoe is to mix my carbs with fats when I have a snack-for example, Greek yogurt with blueberries and banana, or eating an apple with peanut butter.
It will take six weeks to receive your results: two documents by email, a 47-page dietary inflammation report and a 44-page microbiome analysis (long, but without much personal information).
Mine contained no groundbreaking or life-changing information.
My blood sugar levels score 91, "excellent", while my blood fat levels are "good" and my gut biodiversity "excellent".
The foods I had to eat less and less were predictable - more foods that contained lean protein and healthy fats, grains, and leafy greens, and fewer foods that contained refined carbohydrates and processed foods.
The microbiome analysis aims to show you how diverse your gut is populated by good or bad bacteria, as these play an important role in maintaining your gut. a strong immune system.
I was in the top 25 percent of scores, with 121 types of microbes in my gut: my score was 83 - "excellent".
"In general, more diversity is better because it's more likely to contain beneficial microbes," says Zoe.
After you get the results, you move on to the final stage, which is maintaining better food choices. The app says it can predict blood sugar responses to foods and suggest responses that will keep you at a higher level.
I didn't feel like I was getting much useful insight.
Is it worth the money? I'd say most of us already know what we need to do to become healthier: eat less sugar and more plant fiber, healthy fats, and a greater variety of nutrient-dense ingredients; prioritize healthy proteins and gut-loving foods; and cut out processed foods. Exercise regularly And getting enough sleep are also key.
A blood monitor and app will not take those steps for you.
I canceled my app subscription.