Home
The Secret Diary

The weekly newsletter

The Secret Diary of Kombucha Kev.

A normal bloke, a kombucha shop and a wellness industry that wants you rubbing butter in your eyes.

Every Saturday at 11am: my secret diary from behind the counter in Otley, the week's gut science minus the hype, and the kombucha and alcohol-free drinks actually worth your money. Funny, honest, and occasionally fact-checked by a clinical nutritionist.

Inbox · Saturday

Kombucha Kev 11:00 Same glass. Every day. The Secret Diary of Kombucha Kev
Kombucha Kev 11:00 I declare war on the oat milk tax The Secret Diary of Kombucha Kev
Kombucha Kev 11:00 I used to look six months pregnant by 3pm The Secret Diary of Kombucha Kev
Kombucha Kev 11:00 I start a newsletter, against medical advice The Secret Diary of Kombucha Kev

Read aloud to the cats.
The cats left.

Hello. I'm Kev.

Not a doctor. Not a biohacker. Not an influencer.

Just a normal bloke from Otley trying to look after his gut while social media tells him to rub butter in his eyes to see better. I spent ten years in public health and behaviour change, then opened a kombucha shop. The Secret Diary is what happens when you let that man near a keyboard every week.

I'm 46¾ (the ¾ matters). I live with a partner who won't marry me, a daughter who finds me embarrassing and now belongs to The Smiler, two cats who are my harshest critics and two guinea pigs who are my biggest fans. I own zero jade eggs.

Sticker of Kombucha Kev holding up bottles of Gut Feeling Zero Drama and Root Cause kombucha

Sticker of Kev's daughter hugging a yellow Smiler teddy bear. She belongs to The Smiler now.

What lands every Saturday

One email. Four things. Zero detox teas.

01 The Secret Diary of Kombucha Kev

Monday to Friday, what actually happened. Theme parks, pies, parcels and the occasional existential crisis about the price of oat milk.

02 Gut science, minus the hype

The week's new research, read by me so you don't have to. Fact-checked so I don't get sued. If it was only tested on mice, I'll tell you it was mice.

03 What's new in the fridge

Honest takes on the kombucha and alcohol-free drinks worth your money. And the ones that taste like a beige cardigan.

04 New stuff, first

Fresh episodes of The Health Hype Roast with clinical nutritionist James Ellis, new guides, videos and what's on at the Otley Taproom.

A page from the diary

This is roughly what you're signing up for.

Real entries from the Secret Diary, the week's gut science in plain English, and the latest Health Hype Roast. Lightly trimmed. Nobody was harmed, apart from my dignity.

Read past issues

Monday Decided to start a weekly newsletter. My partner asked who it was for. I said "the people". She asked which people. I went and stacked the fridge.

Tuesday A man on Instagram with a jawline you could slice bread with told me to put butter in my coffee and stare at the sun for ten minutes. I had a kombucha and stared at a spreadsheet. Similar effect on the eyes.

Thursday Someone asked if kombucha would "detox" them. I said the only things that detox you are your liver and kidneys, and they've been doing it for free since you were born. She bought a box anyway. A win for science.

Friday Read this newsletter aloud to the cats. The cats left the room. Read it to the guinea pigs. They squeaked, which I'm taking as a standing ovation.

Until next Saturday,
Kombucha Kev

Plus: the gut science round-up

Read by me so you don't have to. Fact-checked so I don't get sued.

Every week I go through the new gut health research and tell you what it actually found, who it was tested on, and whether anyone should be putting it on a T-shirt. From a real issue:

Nature · Stanford & UC Santa Barbara Our ancestors' gut bugs are going extinct (in us)

The Hadza in Tanzania and the Tsimané in Bolivia share 1,231 gut bacteria species. Around 60% of them are rare or missing in people living industrialised lives.

Kev's verdict: unresolved, but eat more plants

Nature · NYU Langone Sugar and antibiotics: a bad double act

173 hospital patients, 9,000+ meals. More sugar around a course of antibiotics was linked to more loss of gut bacteria diversity.

Kev's verdict: an association, not proof. Go easy on the biscuit tin

Food Bioscience · University of Minnesota And one about kombucha (in mice)

Mice given kombucha for seven weeks showed fewer anxiety-type behaviours, and their gut bacteria shifted. The lead researcher calls it "preliminary".

Kev's verdict: they're mice. Not a T-shirt yet

Plus: the latest Health Hype Roast This week's podcast, straight to your inbox.

Every issue has the newest episode of The Health Hype Roast, where I ask the daft questions and clinical nutritionist James Ellis brings the evidence. This week: Supplements: Expensive Pee or Worth It?

Listen to the podcast

What you won't get

Things I promise never to send you.

~~A 30-day detox plan~~
~~Butter coffee~~
~~Discount codes with a countdown clock shouting at you~~
~~Crystal-activated water~~
~~"Wellness journey"~~
~~Photos of me in Lycra~~ (it shrank in the wash)

★☆☆☆☆

"Left the room halfway through."

The cats, joint review

★★★★★

"Squeak."

The guinea pigs

☆☆☆☆☆

"Please stop reading it to me at dinner."

Kev's daughter

Small print, in big print

Questions people actually ask.

When does it arrive?

Every Saturday at 11am. Late enough for a lie-in, early enough to read with your first brew.

Is it free?

Completely. The only cost is your dignity when you laugh out loud on the bus.

Will you sell my email?

No. I can barely sell kombucha to my own family. Your email stays with me, and you can unsubscribe in one click whenever you like.

Is it medical advice?

No. It's a normal bloke reading the research and telling you what it says, minus the hype. For anything about your own health, speak to a qualified professional. On the podcast that's usually James.

Do I need to live near Otley?

Not at all. Most readers have never been, though the taproom at 7 Manor Square would love to meet you.