Horizon

Imagine if the food you choose could clean your body

and make you feel well.

Imagine if you could become not just healthy, but healthier,

by eating fresh, natural ingredients.

This is the promise of the growing clean eating movement.

We all know it's good to eat healthily.

But clean is a totally new approach to food, driven by social media.

Hello, sir. I'm looking for some bones.

Beef bones, sir? No problem.

Are they synthetic hormone free?

Hormone free. Fantastic.

There we go.

I'm Dr Giles Yo.

As a scientist, I discovered that genetic changes

can increase appetite and obesity.

I'm going to investigate the messages

that the new gurus of clean are selling us.

We're starting with Hemsley and Hemsley.

Fish curry tonight, it sounds great.

Millions of us are embracing this new generation of cooks.

This is from Honestly Healthy.

Clean, and diets like gluten free are the latest fads,

and they're big business.

What do you need after a run? Almond butter quinoa.

From Deliciously Ella.

Once, diets like Atkins were all about losing weight.

Now, clean's pitch is that food can improve your health.

But does it actually work?

I'll reveal the ideas and the people who are influencing

the gurus of clean.

Hello, guys. So, I'm off on a week-long trip stateside.

I find all is not always what it appears to be.

I'll challenge one of the key figures

fuelling the gluten-free fad.

Are you saying that the consumption of grains are harming all of us

to some degree? Yes, without exception.

Without exception? Without exception.

I'll track down the pioneer of alkaline eating

who has made millions by

claiming vegetables can keep us well, and even reverse cancer.

All sickness and disease can be prevented

by managing the delicate pH balance of the fluids of the body.

My investigation sets clean against science, promise against proof.

Ultimately, what I really want to know is,

when it comes to clean food...

can we really eat ourselves well?

To find out how the clean movement has become so popular,

I'm going to cook for someone who has become

one of its most influential figures.

Ella Mills is Deliciously Ella.

She has nearly a million followers on Instagram

and her debut cookbook was the fastest-selling ever in the UK.

Hello. Oh, hi! Ella. Nice to meet you.

I've been nervous. I've been nervous because I'm going to cook for you.

OK. No, it's going to be amazing.

And I normally cook for carnivores, it's a terrible thing to say.

OK. Don't worry. Obviously, I'm cooking for you,

and so I'm going down the route of your philosophy, using plants.

'I'm going to cook Ella's spiced sweet potato stew.'

It's nice and easy. You have to forgive me first.

No, I can't wait to see it.

Before you actually...

'Like all her food, it is vegan.'

Have you always been this veggie person?

Have your always been a plant lover? No, God... Oh, my God, no.

I was actually the worst...

I was the least vegetarian person you'd have ever met in your life

ten years ago. Hated vegetables.

Hated fruit. No sweet potatoes? Not even a sweet potato.

Ella decided to change her diet when she developed a rare condition

called postural tachycardia syndrome.

I had the kind of classic issue of POT,

which is you can't control your heart rate properly

and then your blood pressure drops,

and my digestive system wasn't working,

and then I had problems with my immune system,

and infections and chronic fatigue.

So I spent about six months or so in bed just taking all these drugs

and they just didn't have enough of an effect.

'As the medical options ran out, Ella did what many of us would.'

Obviously, went to Google, because that's what you do these days.

Professor Google. Professor Google.

Which obviously can be a dangerous game,

but I started researching alternative things I could look at,

and I came across lots of stories of people who had used a change in diet

and lifestyle to help manage all kinds of conditions,

which, to be honest, I was incredibly sceptical of.

It seemed quite bizarre to me that you could...

that that could be an effective thing.

But at this point, kind of, you know,

anything is worth a try, really.

'Overnight, Ella gave up meat, dairy, refined sugar,

'gluten and processed foods.

'Her story of how she changed her diet to change her health has proved

'hugely influential.'

It was quite cathartic for me the first time I shared it,

but it was also amazing, the number of people who would get in touch and

say, you know, that they could relate to it

for some reason or another.

I think that was also another reason to keep talking about it,

cos it made sense of what I was doing.

Ella has become one of THE faces of clean eating.

The movement grows by sharing images of perfect-looking food

on social media sites like Instagram.

Type hashtag cleaneating into Instagram...

and you get more than 26 million posts.

I often post images of food on social media,

particularly Instagram. Do I post images of food?

Yes, I try to do that at least once a day.

Sometimes twice.

The NHS recommends a balanced diet to stay healthy and cut the risk of

heart disease and other conditions.

But more and more of us are inspired by the clean gurus' message -

eating their way will make us well.

My favourite recipe is probably something called zoat,

and you're going think I'm crazy,

but it's courgettes grated into oats.

Quinoa porridge, and I'll put it with coconut milk, add flaxseed

for fibre, turmeric for, you know, anti-cancerous properties.

I really need to be a part of this,

so I'm going to set up my own Instagram account

so that I can document

my investigation of the clean phenomenon.

All right, here we go.

To investigate clean's promise that we can eat ourselves well,

I need my own forensic space.

Individual clean recipes are no doubt healthy,

but I'm focusing on the overall approaches to food these new gurus

are promoting, and how they prove they work.

Alongside Ella we have the Hemsley sisters, Jasmine and Melissa,

and Natasha Corrett of Honestly Healthy.

All of them have claimed that by changing their diet

they have improved their health - and what does this actually mean?

Science, after all,

is about telling the difference between anecdote and evidence,

and something that works for one person doesn't necessarily work

for very many people.

But clean isn't built on science.

It is bringing into our kitchens

approaches to food that are influenced by ideas

that range from the unproven to the peculiar, to the sometimes,

when taken to the extremes, harmful.

The Hemsley sisters have published two books and had a TV series.

They promote the health benefits of traditional foods,

and make some colourful claims.

I'm about to make bone broth.

The Hemsleys call this the ultimate superfood,

one of the oldest home-made foods, apparently.

They say it is an elixir that can cure ailments and nurture the sick.

You might call it stock.

But the Hemsley sisters' approach isn't all about ancient foods.

In fact, they're also helping fuel the biggest food fad of all.

Across the Western world,

more and more people are cutting out one foodstuff we've eaten every day

for millennia -

gluten.

What kind of bread are we going to be making?

We're making gluten-free olive oil focaccia.

Gluten is a protein found in wheat, barley and rye.

Gluten is just what it says it is.

It's glue, it glues things together.

It's a binding agent.

'Gluten-free bakeries like this were once rare.'

Most of our customers are coeliacs

and what happens is, when coeliacs ingest gluten

they tend to get an autoimmune effect.

The immune system of people with coeliac disease mistakes gluten for

a threat and attacks it, damaging the intestine.

The condition affects around 1% of the global population.

The number of us going gluten free is far higher.

So, how does it feel? Oh, dude.

That's awesome.

That is fantastic.

This is gluten... This is gluten free, guys.

The clean gurus are united in promoting gluten-free food.

But the Hemsley sisters take this restriction one step further.

Now, the Hemsleys are not just gluten free,

they are also grain free, and they seem to have arrived

at this position via this chap over here, William, or Bill, Davis,

who wrote a book called Wheat Belly.

They say he describes how eliminating grains from your diet

can have an incredibly positive effect

on your overall health and wellbeing.

So who is Dr Davis?

And how objective is he in presenting the evidence?

Time to find out.

Wheat country, Ohio.

Before the harvest, it looked like this.

Today, it is a fitting place to meet an anti-wheat evangelist.

Science is complex, it's full of grey areas.

There are always caveats to how things work.

It is very, very seldom black or white.

What I want to know is,

is whether or not Bill Davis is reflecting the true complexity

of the science of gluten,

or is he exploiting that grey area and fuelling unfounded fears?

Intriguingly, Bill Davis was a cardiologist

for more than two decades.

Bill? Hi, I'm Giles.

Glad to meet you. Pleased to meet you.