All language subtitles for R.I.L.S2024E03.WEB-DL_track3_[eng]

It's time to talk about food.

Now, most organisms
eat other organisms,

like plants or animals
that eat plants.

Don't eat me!
You've got a whole cow there.

Lamb chop?

No, I ate before the show.

Only humans eat what we call food.

We've made it, we've bred it -

it's stuff that's deliberately
created to be eaten.

And it's the variety
and complexity of our diet

that sets us apart as a species.

But, over the last few decades,

our food, and the system
that produces it,

has changed beyond recognition.

And this has created a few problems
which we're going to need to solve.

APPLAUSE

Welcome to the Christmas Lectures
from the Royal Institution,

supported by CGI.

I am Chris van Tulleken,

and tonight I'm going to take
you through a history of eating,

especially human eating,
on planet Earth.

Will our timeline please stand up?

So this is a timeline that takes us
from the formation of planet Earth

4.6 billion years ago.

Give a little wave.

And it goes all the way through

to what you ate for breakfast
this morning over here.

And our story begins...

Let me run up here.

Our story begins with
one of the first meals

eaten on planet Earth.

I'm going to pass it down,
and we want that to get

to about 4 billion years ago.

We're going to represent that
with a bowl of rusty soup

on the timeline.

And to help make this meal,

I want you to please welcome

the director of the
Institute of Making,

an expert materials engineer,
Dr Zoe Laughlin.

APPLAUSE

Talk me through it, Zoe.

OK. This represents the Earth
at the dawn of life.

OK. This is the ocean.

It would have been quite hot,

so it could have been
boiling at some point,

but it was remaining liquid with
an insulating layer of CO2.

OK. So here we've got
some dry ice in the water,

creating CO2 gas,

but also dissolving
into the liquid itself.

The sea would have been
very rich in CO2.

We also have a volcano.
Of course. Of course.

It's a very hostile environment. OK.

But these are the conditions
for the first meal.

All right.

So you're going to make
this first meal.

OK, I will. A few
safety specs required.

Of course I'll need safety goggles.

And, like any chef,
I need a blowtorch.

For, like, you know,
caramelling the top?

A little bit of creme brulee
on your meal. OK. Great.

And this is going to be like one
of those puddings with a hot centre.

Is it a baked Alaska?
What am I thinking of?

There will be a molten centre,
this is true. Great.

But, well, let's see how
much you want to eat it.

OK...

I'm going to light magnesium
strips inside this volcano,

all being well. Now...

OK... Whoa!

Whoa! Sparks are flying.

OK... Oh! Whoa, whoa!

OK. So...is this the meal
that's pouring out the bottom?

That is the food coming out
of the bottom of the volcano,

into the water.

I'm going to stand up
behind some audience members.

It's still ablaze,
even though it's underwater.

Can we get it? What is it?

Now, be careful, because
I think this is still hot.

Let me feel the tank.
Yeah, that's warm.

So I think the next job is for you
to fish for your supper, please.

OK. In you go.

Lower this in.

There we go. OK...

And it's stuck to this.

There it is. There it is.

Your meal!

OK, so this... It's stuck to
the magnet. What is this?

This is iron.

This is raw iron?

Raw iron. Pure iron.

What we've done here
is a thermite reaction,

so we've mixed iron oxide
and aluminium powder,

and, with the magnesium ignition,
it's created an extremely volatile

exothermic reaction -
over 2,000 Celsius -

that generates molten iron

that was dripping into the water
and then solidifies.

And there you have it, pure iron.

This iron would have been the food
for some of the very first

microbes on Earth.

Early life would have
been eating this iron,

breathing the carbon dioxide,

and excreting out
a rust-like substance.

And they've been doing
this in the sea,

and all of that detritus
would fall to the seabed

and form strata of iron oxide.

And that's the seams that
we're mining still to this day

to create objects out of iron,
like the railings of the building

we're in, making our modern world.

It's come from early bacterial
poop that's sedimented,

and then we've turned it back
into iron to create our world.

Yeah. That is incredible.
And this is still going on today.

So, in fact, if I just grab
this bicycle, this trike,

you'll see... What is this?
Well, this is actually my own trike.

Is it really? 40 years old
this Christmas.

And this is the rust that's,
you know, occurred over time.

But this has occurred because
we have oxygen in our atmosphere.

So it's not the same reaction,

but those same microbes
are in there,

feasting on the iron and
taking advantage of that oxidation.

So the first life is eating stuff
that's never been alive,

and those bugs
are still at work today? Correct.

That is fantastic. Um, Zoe,

an amazing demonstration,
a terrible meal,

but I think there is more to come!

Everybody, Dr Zoe Laughlin!

CHEERING AND APPLAUSE

So, can our timeline
please stand up again?

And I'm going to put
Zoe's rusty tricycle...

Let's put the rusty bike
right back here at this end.

Because those autotrophs,

the life that takes
inorganic material

and turns it into organic material,
living things,

those bugs, those bacteria,
they're still alive today.

So we've got our rusty soup
at that end.

And in the history
of eating on Earth,

something happened pretty quickly,
we think. After that, life existed.

So, we've got bugs starting to eat
things that have never been alive.

And pretty shortly afterwards,
life figured out a short cut.

Bugs started to eat other bugs.

So let's put that there.

So very, very quickly,

life figures out
it's easier to eat other life.

And this sets up
something called an arms race

because we've got life needing to eat

and life that does
not want to be eaten.

And they have to evolve so that
one can keep eating the other

and one can keep
avoiding being eaten.

So we're going to hustle
through the next few billion years.

We get the evolution of complex
cells somewhere... There we go.

We get increasing
complexity in cells.

1.5 billion years ago, approximately,

we see the evolution
of multicellular life.

Life is becoming more complex
because of that arms race.

Then, 530 million years ago,

approximately, the evolution
of primitive fish.

And from those primitive fish,
a creature called Tiktaalik,

a fish with legs,

that started to come
out onto the land.

After Tiktaalik, we see shrew-like
mammals 225 million years ago.

And it was these creatures
that survived

the age of the dinosaurs and from
which the age of mammals flourished.

And then we're going to move
from the shrew-like thing

to the early apes,

around 30 million years ago there.

And, finally, I want to get us
to 2.5 million years ago.

Now, 2.5 million years ago,
it was a really, really important

moment in human eating.

These are the apes
we're descended from,

and Zoe has prepared a meal

that apes at this time
would have been eating.

So we now have a
2.5-million-year-old meal.

Is that right, Zoe? Yeah, I'm
really pleased with this one.

I think you're going
to enjoy it. OK.

This is better than
the raw iron? Yes.

First things first, Chris, you
need to dress for dinner, please.

What is this?
Like, clothing of the period?

Yes, it's a special occasion.
OK. A little jaunty number.

Can you do me up? Quite right.
There you go. Lovely.

Now, you're hungry? Yeah. Right.

Here we go. First off, we have...

..some tubers. Right...

So some raw root vegetables
covered in dirt.

OK, great.

What goes with them?

Well, the piece de resistance...

Are you ready, sir? Mm-hm.

Your lamb!

A leg of raw lamb? Yes.

You haven't cooked it at all?

No, I mean, I've caught it,
killed it,

butchered it, skinned it.

It's ready to roll! You don't expect
me to eat this? Raw. Go for it.

Tuck in, please.

OK...

This is real raw lamb.

OK, er... OK, I'm going to
have a go at that bit.

AUDIENCE GROANS

Please do not try this at home!

Raw meat contains parasites,

bacteria.

But Chris is an infectious
diseases doctor,

so he has informed consent here.

He knows what he's doing
in this demo. Do I?!

I think your agent signed something.
I think it's fine.

Well, I'm not doing enormously
well, I have to say.

What I'm struggling with is
this white connective tissue.

The tendon. I mean, that's
a bit of the tendon there.

Yeah. Can't make any progress at
all. This is extremely tough stuff.

So this is attaching
muscles to bones

and, when the muscles contract,

it's, you know, articulating
those limbs. Right.

So this is an example of food
that does not want to be eaten.

This hasn't evolved
to be eaten. Yeah.

And you mentioned the tendon there.

I've actually prepared
a little demo on tendons for you,

but first I need you
to wash your hands, please.

OK. I'm going to put
that to one side.

I think what I can confidently say,
and I've never tried that before,

is I could be with that all day,

I wouldn't really get anything
useful out of it.

I cannot make anything... Then I
don't know if you're really trying.

I'm going to go and
wash and change. Thanks, Zoe.

OK, I'm going to need
a volunteer for the next part.

Oh, my goodness, loads of you!

Right. In the middle with
the fringe and the T-shirt.

Come on down!

APPLAUSE

Hi, there. What's your name?

Amelia. Amelia.

Welcome to the stage, Amelia.

And lower the tendon!

Here we go.

OK, Amelia, what I have here

is a small section of tendon
from the foot of a cow.

Now, this is very tough material,

but we really want to
know how strong it is.

To test that,
I'm going to hang you...

No, I'm going to get you to attach
these weights to the tendon.

OK?

So let's begin,
just with a kilogram.

Hi, Amelia. Did I get
the name right? Yeah.

Good. OK, so hang them up.

How's that? It's not too heavy,
is it?

So we've put a carabiner
through the tendon, so just hang

that on the piece of metal.

Lovely.

OK. OK. 1kg, no problem.

Let's have a look.
The tendon isn't extending.

Three kilos.

I mean, this is...nice.

Nicely done. Nothing much.
No problem there.

Four kilos, no trouble. I think
we take this to the next stage.

Let's go 15kg.

OK.

OK. Now, Amelia, I want you to
feel how heavy that is, OK?

I'm not going to...
Put both hands under, OK?

Yeah. It's heavy, isn't it?

Right, let's stand back
a tiny bit for this one.

Chris, you can have
a go at this one. OK.

OK. I can see the whole kind
of rig-up stretching,

but the tendon, not so much.

Maybe a millimetre or so.

It seems happy enough.

Let's go for bust.

That's 15. Let's add on... 20 kilos?

25 kilos?

So this is now going to be the
same weight as you, give or take.

There you go. You got that?

Yeah. Yeah, yeah.

So there'll be a good 40kg on here.
Easily the weight of a child.

Right...

Oh...

OK. You're on.

OK, I'm going to load
that very gently.

Oh. So, again, most give from the
rope, I think, more than the tendon.

Yes! Yes! The tendon is holding!

This is the power of tendons.

Look at that. This is so strong.

In fact, if we took a bigger tendon,

we could hang it from the ceiling
and suspend a car.

Really? So we're limited
mainly by the strength

of the theatre ceiling
at this point,

more than the strength
of the tendon? Yeah.

So we could all hang off that?

You, me, Amelia, swinging away.

So brilliant work, Amelia,

but I think you do lose
this first round of

human versus tendon, don't you?

It is 1-0 to the tendon! Tendon!

And I think, actually, what
we've seen really clearly is

that's why I can't eat the lamb,

because tendon and those connective
tissues are incredibly tough

and hard to bite through. Yes.

Brilliant work. Thank you very much.
Thank you, Zoe. Thank you, Amelia.

APPLAUSE

I want to now look at
the anatomy of an animal

that might have been able to
eat that meal better than me.

To help me, I want to welcome
the head of Heritage,

who looks after the museum
and the archive here at the RI.

This is Charlotte New.

Now, what I've got here
is two skulls.

This is a modern human skull.

OK? So very much like yours.

And this is Australopithecus,

who lived around
2.5 million years ago

and was eating that meal
that we just saw.

And I want you to look at the
differences between these skulls.

OK? First of all, the most obvious
thing is the modern human

has an enormous brain compared
to your great-great-grandparent.

OK, but it's our great times
120,000 great-grandparent.

So how does this creature
evolve into this one?

Well, I want you to look at
what the skulls are made of,

particularly at the jawbone.

OK?

Because the bones on this head
are much, much bigger and heavier.

And this is particularly obvious
when you look here.

If you see,
the modern human jaw is smaller,

it's much more fragile,
the teeth are tiny.

And when you're comparing those jaws,

remember, this head
is all about processing food

that's hard to chew with
the muscles and the bones.

Now, both of these animals
have to be born through

a human pelvis - a ring of bone -

and that constrains
the size of the head.

And this is the problem.

The space in your heads is basically
taken up by three different things.

Your brains, your muscles
and your bones.

The space in the
Australopithecus head

is mainly occupied by enormous
chewing muscles here and here

and these very, very heavy bones.

It needs that chewing apparatus
in order to eat.

The human head is occupied -

the modern human head - the space
is occupied by the brain.

So Australopithecus is in a trap.

How does Australopithecus escape
the trap and become a modern human?

I know, Chris,
I have the answer for you,

and it lies at the end of
this very large plastic tube

that many of the audience
members are holding for me.

So I've been filling this
with highly explosive gas,

and I'm going to set it
on fire any minute now.

OK... Lights down, please!

Here we go. Three, two, one!

Here we go.

Here it comes. So magical, isn't it?

Whoa! Whoa!

APPLAUSE

So the answer is fire.

Zoe, that was an amazing demo.

Now, people might be tempted
to try that at home.

Would that be a safe thing to do?
Absolutely not.

Do not try doing that at home.

So, 2 million years ago,
when early humans learned how to

harness fire, everything changed.

And I think it's time for another
round of human versus tendon.

Brilliant. Lower the tendon!

OK. So this is the original tendon
in here?

This is the original tendon.

If you remember, this held 40kg,
no trouble at all.

OK. Now we're going to
swap out the tendon.

So it's from the same part
of the cow.

The only difference is
this tendon is now cooked.

So, at around 40 degrees,

the proteins in the tendon
start to denature.

They change. At 50-60 degrees,

they actually gelatinise

and become much, much more tender.

And you can see that difference.

If we look at this tendon now,

it's actually feeling all kind
of wibbly wobbly, rubbery.

Shall we load it up? Load it up.

Let's begin with a kilogram again.

That's what we started
with last time.

OK, here we go.

Just put that there, like that.

Whoa! OK!

Oh! So actually we can see this...

In fact, I think I can just...

Yeah, I mean, this is
now so much weaker

that you can bite through
this no trouble at all.

Can I actually do that?
If you want, you're the doctor.

Yeah, I can do that. Slightly salty.

I'm not going to pursue that.

I don't quite know how this
was prepared, but it was...

You cooked this for some time?

Yeah, for an hour at about 70.

OK. You know, it's...it's jellified.

It's not totally dissolved.

You could keep going, and that's
how you get stocks and things,

by the dissolving of those
connective tissues

and that collagen
that adds to meaty broths.

So, Zoe, that is a brilliant
demonstration of how the material,

the physical structure
of food and tendons,

but other foods as well,
is changed by cooking,

making them easier to chew.

Zoe, thank you
for another brilliant demo,

and I think another meal is upcoming!

Zoe has beautifully explained
how cooking changes the structure

of food, its engineering properties,

making it easier to bite and chew.

But cooking brings
other advantages too,

and this was first shown
by a team at Harvard University.

And for our next guest,
I want to welcome

a crucial member of that team
of scientists.

But you need to clap
very quietly for them.

Please welcome Monty.

Monty, being held by Mark.
Hi, Mark. Hi, Chris.

How are you going? How are you
doing? Good. So talk us through.

Who is Monty?
So Monty is a Burmese python.

Python bivittatus.
They're a constrictor.

That's how they eat their food.
I can see that!

Yeah... No, they're just....
That's just holding on.

But they have a real immense power.

OK. Now, can I hold Monty? Sure.

How do I do it?
We'll have a go. OK.

It's a de-wind, isn't it?

How heavy is Monty?

Er, it's not so much the heaviness.
It's the... It's the weight -

it's the power. It's the power.
OK. Hi, Monty.

Hi, Monty.

Oops! You'll feel...it'll
transfer to you.

So the reason we've got Monty
here... Do stay close, Mark!

LAUGHTER
The reason we've got...

The reason we've got... Immensely
powerful! Immensely powerful.

Um, the reason we've got Monty is
because the team of scientists...

Oooh!

..the team of scientists used...

When did Monty last eat?
Just let go of your hand.

So I've been putting it off -

putting it off to keep him
for this show. OK!

So he's going to have
a couple of rabbits tomorrow.

Great. Great. Good.

And, um...

So the team of scientists
used Burmese pythons, like Monty,

and they did an experiment.

They fed snakes like Monty
two different meals.

One meal was raw chunks of meat,
like snakes normally eat,

and the other was ground cooked beef.

And what they found was
that the snakes used 25% less energy

to digest the cooked, chopped meat,

so there was more energy to start
developing the human brain.

We start to see how cooking releases
Australopithecus from the trap.

But cooking brings other advantages
as well, doesn't it, Monty?

Because it also cleans food

and so, when you cook meat,
you kill all the parasites in it.

It's very nice...

Um, do you want...

Does anyone want to see?
Do you guys want to see?

Come over here. Who wants to see?
Do you want to have a little...

You can... Can they touch Monty?

Absolutely, yeah. And what would be
the largest meal Monty would eat?

You know, compared to
one of these guys?

Oh, a big...
Maybe ten-foot alligator.

OK. Oh, really? OK!

So bigger than these three?

Yeah. OK.

But humans are fairly safe because
our shoulders get in the way.

So, cooking kills parasites.

Parasites, if you're fighting them
the whole time,

like all the other carnivores were
having to do 2.5 million years ago,

fighting those parasites
also takes a lot of energy.

So cooking starts to release
a huge amount of energy

for brain development.

Now, why did they use Burmese
pythons, or pythons of any kind?

And the reason is that you
can put a snake in a tank

and measure everything about it
very easily over several weeks.

Monty, you've been
an incredible guest,

and I think I'm going to gently
hand you back to Mark

so that we can get on to a wider
discussion of food processing.

Can you...? Are you all right
getting him off me?

Done. Lovely stuff. Monty and Mark!

Are they OK to applaud?
Absolutely, yeah.

Snakes are deaf to airborne noises,
so there you go, he's in the air!

All right. Big round of applause!

So the first processing
is cutting and cooking,

happening around about
2 million years ago.

And then processing
really, really took off.

It changed our anatomy,
our physiology, our genetics.

And for hundreds of thousands
of years of our evolution now,

we've been chopping and grinding
and pounding and smoking

and salting and fermenting.

Humans have to process our food.

If you look at our tiny little jaws,
our small teeth,

our very minimal chewing muscles,

we are the only animals
that cannot survive

without food processing.

Other animals use their teeth
and their guts.

We do it with tools and fire.

Now, we started processing wild food

and then we started domesticating
animals and plants

and processing them.

And that was the dawn of farming.

So I want to go back now to
14,000 years ago on our timeline,

the dawn of agriculture.

And it's when we started to make
foods that we recognise today.

And, Zoe, I think you have
some of these foods here.

Yeah, right.

Ready for our next meal.

But I'm going to need to enlist
the help of the audience

for some collective food processing.

So I have two liquids in these jars.

Chris, if you take one,
we're going to hand these out.

We'll start at the back
and we want you to pass it along

so it comes down to the front,
just on the two sides.

But what I want you to do
when it comes to you is shake.

Like, really, really shake.

No, Chris. Come on! Really shake!

Da-da-da... The full enchilada!

Yeah. You've really
got to go for it.

And then, when your arms are tired,
pass it on.

So about ten seconds until
you're exhausted? OK!

Up to the back.
Shake and pass it on.

OK, we can start with you,
and it will snake its way back

through the audience.

Really up high so we can all make
sure you're doing it properly.

That's it! Now I'm going
to draw your attention

to this ancient
food processing tool.

This is a saddle quern. It's over...
A what? Saddle quern.

A saddle quern?
9,000-year-old tool. OK.

And we need two volunteers
from the audience.

Let's have stripy top
and Fair Isle cardigan.

Come on down.

Lovely. What's your name?

Fiona. Fiona and...? Sam.

Sam. Sam and Fiona. OK.

What I'm going to do
is put you to work.

One of you, please...
Sam, you sit here first,

at this end.
You'll both have a go at this.

Come and sit on the floor,
facing this way.

Fiona, you're in charge
of this sack, right?

Two hands on the stone
with thumbs tucked up

so you don't crush yourself.

Don't grind your thumbs,
Sam. We don't want that.

Yeah. And what you're going
to be doing is grinding wheat

that Fiona has in her sack.

You just sprinkle in
a few more wheat grains.

Now, this might feel like hard work,

but I promise you, I mean,
I've done the hard work for you.

I've domesticated the wheat.

I've grown it, I've harvested it.

All you've got to do now
is please grind this,

fill this sack with flour,

and then we'll be able
to make some bread.

The way I'd understand this is

now Sam and Fiona have started
to chew for the whole community.

Australopithecus was having
to do this kind of stuff

with its jaw muscles
and its molar teeth

if it wanted to eat the seeds
at the top of a stalk of grass,

which is what wheat is,

and now these guys are
doing it for everyone.

Yeah, it may feel like hard work,
but it's actually highly efficient.

And not only that,
you're producing a new material.

You're making flour.

Once you have flour,
you can start making breads,

cakes, Danish pastries...

All kinds of things start to happen.

OK. How are you getting on?
Do you want to swap round?

Yeah. OK, have a swap.

How's this other stuff doing?

Shake it! Shake it hard. Pass it on.
We've got to get it to the front.

Right, let's have a look. OK.

Not bad. How does it feel?

It's quite hard, but the
flour is coming through.

The flour is coming through.

You're actually producing
a fair amount.

I mean, not yet a teaspoon.

So you've got a way to go
before you fill your sack.

But that is flour.

This is magical stuff.

This will now last much longer once
it's dry than the wheat on its own.

And, as you say, a brand-new
type of substance,

one that previously, you know,

it was digested as soon as
it was made in our mouths.

OK, I think we should
get the other stuff down. Yes.

Do you think it will be ready now?
Well, we can try.

Let's say thank you
to Sam and Fiona first.

Thank you. Where's that jar?

Keep going, gang.
Come on, come on, come on, come on!

Pass it straight down.

Shake it as you go.
Shake it as you go.

There we go.

Now, yours is still quite sloshy.

I think mine feels...
Mine feels funky.

Oh, slosh and funk. Try it.

I'm not sure. That feels more
solid. Have I got to keep going?

Yeah, keep going with
that one for a bit.

Well done, this side.

OK! So what... Can anybody think

what we might be trying to do here?
At the back!

Make butter. Make butter. Correct!

What is bread without butter?
Indeed!

It's very sad, that's what it is.

But this is an ancient process.

Let's have a little look inside.
We can...

Now... OK.

This liquid, this is the whey.

Oh, and there we have...
Oh, look at that! ..our butter.

And we really did start with cream.

Yes, so what's happening
when you shake that container

is the cream is smashing
into itself inside

and the fat globules
are coming together -

they're coagulating
and they're amassing so much so

that they then amass to form
that lump, which is butter.

Transformative stuff.

Again, it's another new food product.

Zoe, a fantastic demonstration.
You're welcome.

Thank you very much indeed, and I
think there's more meals to come!

I'm just going to take
a scoop of butter here.

I just want a little bit.
Just want a little bit.

Butter is extraordinary stuff

because, when humans first
domesticate other mammals,

it seems obvious that drinking
the milk would be a good idea.

But milk, when they first do this,

they're doing it in
very hot, tropical places.

Milk spoils within hours
and then becomes very dangerous.

The advantage of butter
is that you've taken most

of the energy out of milk.

You've taken the fat and,
because it's a solid,

the bugs can't move through it.

And so you're preserving the energy.

So let's put the bread and
butter on the timeline.

Here we go. Bread and butter.

And we're down to
the last few millimetres.

I'm going to clip that on there.

In fact, these are going to overlap.

Um, this is the dawn of what
we might think of as modern food.

Can you just hold them?
Thank you so much.

Great.

So, from the dawn of agriculture,

we start to eat a greater
variety of foods.

6-10,000 foods start
making up the human diet,

and farming and food processing
gradually become more mechanised.

We start with stones, and then
it becomes driven by animals,

and then big machinery,

and farming and food processing goes
from being done at very small scale

to being done at very,
very large scale

by industrial farms and factories.

And now almost all of
our food is bread -

grown, harvested, processed -

and then sold by extremely
large global companies

that form part of a huge
industrial global system.

And what's really important
to say is this has brought

a massive number of benefits

because the corporations that
grow and produce our food

weren't just making
ingredients any more -

they weren't just making
flour and tins of corn -

they started making
finished food products

that had previously
been made at home.

And these products
were very, very cheap.

They were convenient,
they were quick to prepare.

So all kinds of things
started happening.

A burden was taken off women,

who can now enter the workforce
after World War II.

So the industrial food system
brought many, many advantages,

but it also brought some problems.

To help us understand the modern
industrial food system,

in more detail, I want you to
welcome a public health expert

and academic from City
St George's University of London.

She's also a former food engineer
and commodity trader.

Please welcome
Dr Yanaina Chavez-Ugalde.

APPLAUSE

Yanaina, you've brought
a machine with you.

Yes. And, of course,

this is an extreme
over-simplification

of the food system

and, of course, the food industry
that I used to work for.

OK. So you very well explained

that humans used to consume
thousands of species,

but in the past few years we have
only based our foods in four crops.

Which are...

And I'm sure you've
seen this before.

It's like edamame. Soy.

These are soybeans because
I think we recognise these -

people will have had these and
thought of them as edamame.

But they are, they're soybeans?

Soybeans. We also have wheat. Wheat.

We have rice...

..and we have corn.

OK. So you won't believe this

but, today, 50% of calories come
from wheat, soy, corn and rice,

and 20% of our calories
come from corn.

Now, this is a bit surprising

because I want to ask all of you,
in the last week,

how many of you have eaten
a fresh cob of corn,

probably spread
with a bit of butter?

If you've done it in the
last week, put your hand up.

OK, so some corn eaters here,

but I don't think we're
at 20% of the audience.

I don't think it seems like
20% of people's calories

are going to be coming from this?

Exactly. It's because we don't only
consume corn in this shape or form.

That's why I brought my friend,
the Foodamatic 3000.

So, let's see what happens.

MACHINE RATTLES

LAUGHTER

Amazing!

So talk us through this.

We have...
Let's start with corn starch.

Corn starch - I'm sure
you have seen it -

it's a thickener,

and you can use it in yoghurts,
sweetened yoghurts.

It's very common to find it there.

I feel like I see it on ingredients
lists the whole time.

Yes, it's very prevalent
in food. OK.

What else have we got?
So we've got starches.

That's carbohydrates.

We have high fructose corn syrup,

which is a substitute for sugar.

It's way sweeter than sugar

and it's way cheaper than sugar.

OK. So we can get sugar
out of corn as well?

Yep. Sorbitol, which is also
a substitute of sugar.

But as you see, it's not that gooey.

It's just another...
yet another powder.

And it's very good
and very highly used

in, um, sugar sweetened beverages.

So another sweetener.

We have maltodextrin that sometimes
is used in breads as well.

Another sweetener,
another palatable thing that

your taste buds really, really like.

Starchy, carby stuff.

And you'll see this on lots of
ingredients lists, won't you?

Yeah. OK.

And dextrose, usually seen...

It's also kind of gooey.

..in bread. OK.

So another kind of sweet sugar.

So corn's pretty good for the carbs.

And one more.
We also have corn oil.

It's a vegetable oil.

And you can use it and
mix it as a fat substitute for many,

many of the products
that we see packaged

in our food system, the supermarket.

So I'm starting to understand
how, by transforming the corn,

you extend its shelf life,
you reduce some costs,

and now we can have corn
in our breakfast cereal.

We have it in
our mid-morning snacks.

It's in our sandwiches.

It's in our condiments,
in our ketchup, in our wraps.

We start to see corn in everything,
and presumably we're also feeding

some of it to the animals.

Yes, we have food and we
have feed - food for animals

that then we eat, so we end up
eating corn in this,

but also in the meat you were trying
to eat, if that lamb ate some corn.

OK. So we're eating corn
in lots of different ways.

What other kind of things
do we put in the Foodamatic?

Well, you put seven or eight
other crops in this friend,

and you get 75% of the calories.

Really? So our global calorie intake

is now coming from a tiny number
of different species,

all of which can be broken down into
these kind of pastes and powders.

Absolutely. OK.

This is not necessarily a bad thing.

It's driving down the cost of food,

and there are some efficiencies
that come with all this.

Absolutely. And you plant one crop

on one piece of land
and you get all of this.

OK, Yanaina, thank you
very much indeed.

Stay around with the
Foodamatic 3000 because we may

need it again in a second. Grand.

Thank you! Thank you
very much indeed.

APPLAUSE

While Yanaina has been
industrialising the food system,

Zoe has been setting up a small
traditional ice cream business.

So, Zoe, talk us through
what you've been doing.

This is the next meal.
Yeah, I'm really proud of this.

I'm slightly more excited
about this one than previous ones!

I come from a long line
of pudding lovers and makers,

and I'm going to make for you
a firm family favourite,

which is strawberry ice cream.

What's not to love?

Three ingredients - strawberries,

a little bit of sugar,
just to bring out

the best of the strawberries,

and cream.

Now, Chris, if you wouldn't mind
just giving that a good stir,

make sure all the ingredients
are nicely incorporated.

Just three ingredients
in your ice cream? Yes. OK.

And I just need to put
on some safety gear

because I'm going to freeze it
by using the old favourite

of the Christmas lectures,
liquid nitrogen.

And not a traditional way
of making ice cream necessarily,

but it's just a very quick way
of doing things, isn't it?

It is. I'm not wearing
safety gloves,

so I'm going to retreat slightly.

You stand back. Right,
let's pop some in. Here we go.

POPPING AND CRACKING
What are we hearing here?

So this is the rapid formation
of the ice crystals.

So liquid nitrogen
is -196 degrees Celsius,

so extremely cold.

And the trick to
delicious ice cream

are tiny ice crystals,

and you make those
by forming them fast.

There's our ice cream.

A little bit more maybe.
Give it a good stir.

And it's ready!

I mean, I blow it
to warm it up a tiny bit,

but you can try it if you want.
Blow it to warm it up! OK!

Hold on.
Let me just pull off a bit here.

Yeah. It's good to go?
Give it a little blow to warm.

Yeah.

Mm... It is cold!

LAUGHTER

It's cold.
I'm going to style this out.

But tell me that's
not delicious? It...

I can't taste anything!

No, it is, absolutely!
It's really delicious.

So, your business, this little
business you've set up

with your three-ingredient ice cream,

you must be going gangbusters.

It must be absolutely brilliant.
They're queuing round the block.

Are they? So are you going to
expand? You can go global!

There is a problem, which
is it doesn't travel well.

What do you mean?

You can't get it home because it
melts by the time it gets there.

So you can eat it here,
but you can't take it away.

Is it cheap to make?

Well, it's comparatively expensive,
if you think we're using

full-fat double cream,
strawberries and sugar -

they're not the
cheapest ingredients.

Strawberries are a bit seasonal.
Can you get them all year?

You can't get them all year.
You'd have to mix your fruits up.

You know, it can be expensive,
but it's quality stuff.

Brilliant, OK. Well, you've
actually given me an idea.

Yanaina, do you want to come back?

Because what I'm wondering is
Zoe's doing a great job over there

serving her community,

but do you think we could
use the Foodamatic 3000

to make ice cream
that was a little cheaper

and easier to transport?

Absolutely. Guaranteed.

OK. How are we going to do it?

I'm going to show you.

OK, some ingredients.

Now, presumably, the first thing
we're going to need

to start with is some cream?

Of course not!

No? We're not going to use cream?
No. Cream is expensive.

It rots.

So, in substitution,

we're going to use
reconstituted milk powder.

OK. Shall I put that in there?
Yes, please. Right.

And whey protein.

OK, so we've put milk
in the Foodamatic,

but, like the corn, it's
broken the milk down into

its... I guess, a bit of fat
and some carbs... Pour some in.

..but there's not much fat in the
milk powder or in the whey protein.

No, but what did we take out
at the end? Some corn oil.

Corn oil, right. Or sometimes
palm oil is cheaper.

OK, so, instead of using
animal fat or dairy fat,

we're going to use vegetable fat?

Yes. OK, so we've now got
some extracted dairy stuff.

A bit of fat.

What else do we need?
Add some sugar, presumably.

Exactly. If not,
this will not be very tasty!

So we have high fructose corn syrup.

OK. Can you mix for me?

Yeah, I'll mix.
High fructose corn syrup...

And this is going
to be sweet like sugar,

but you said earlier
it was a bit cheaper.

Way cheaper than sugar!

Hard to see this becoming
delicious ice cream.

So the next thing it feels
to me is strawberries.

We are going to need strawberries
at some point

because we're making strawberry ice
cream - that's the whole point.

So I'm going to make you say this

because it's a very
complicated word.

So I'm proposing strawberries,

and you're proposing something
called ethyl methylphenylglycidate.

Yes, in substitution of
strawberries. Which smells...

APPLAUSE

I've been practising that all day!

A few drops. Just a few drops.
Just a few drops.

Is this very expensive?

Er, not really.

Not compared to strawberries.

Not compared to strawberries.
Seasonal, expensive.

It's non-seasonal. It won't go
off... This is non-seasonal,

you just put it in.
OK, so this is starting...

It's smelling of strawberries.

It's still looking...
It's still looking pretty bad.

And it's separating - the oil is
coming away from the other stuff.

Yes, which was one of the biggest
problems of Zoe, right?

So we need something
to bind it together. Yeah?

So, for that, we have diglycerides.

Diglycerides - an emulsifier
to glue the fat

together with everything else.

And then... OK, so that's going
to give it a sort of creaminess

in the mouth... A little mouthfeel.
It's looking grey.

I mean, it looks
absolutely disgusting.

Some colouring? We need a pink!

Yes! Bit of colouring. OK, let's
add some pink... Put a bit of pink.

..colouring there. Stir that in.

And there's one
final ingredient left here.

Xanthan gum.

Yeah. That will avoid
the separation.

It will allow for it
to be transported

without kind of slurping out.

So that will make
our business successful.

We can then transport things.

It will help with that
freezing temperature. Yes.

OK. It's like a bacterial slime.

OK.

So we've now got a pink-ish, er...

..mixture of various different stuff,

none of which
I would really call food,

none of which we use
in domestic cooking.

You're going to put that back in
the Foodamatic. Back in my friend.

And out comes the finished product.
Let's have a look.

After you.

OK, here we go.

Well, that... It's some very,
very convincing looking ice cream.

Can I try? I'm going to try...
It smells.

Smells of strawberries.

Do you want a little smell?

Here, Yanaina, get them
to have a... Smell it.

Smells good. Smells good?

Can you hold it?

Is it cold?

No. No, it's not cold.

That's what I noticed.

Is this... This is not cold, is it?

So this is at room temperature

and, if I hold it like this,
it doesn't flow out of the pot.

Yanaina, that is truly spectacular,

and you did it all without
using any real ingredients.

No strawberries. No strawberries.

No ice. No ice.

No cream. No cream. Spectacular.

Yanaina, thank you very much indeed!

APPLAUSE

And I'm really sorry, Zoe,

you're...you're really
not going to be able to...

Ahhhh!

..maintain pace in the modern...
It's just business!

I don't know why
you're all complaining

because what you all
now have access to

is extremely cheap,
fairly delicious ice cream

that you can buy at any time
of the day or night

at the end of your road.

It works brilliantly well,

and, Yanaina, thank you very much
for a fantastic demonstration.

Thank you!

APPLAUSE

So the food company that
Yanaina and I have started

is now going to end up
in an arms race

with lots of other food companies.

A bit like the arms race
that we saw on our timeline.

Companies are going to have
to compete with each other,

and there are two ways
they need to compete.

They need to sell more food,

and they need to keep the price
of those ingredients down.

And to help me understand a bit more

about how I might optimise
my food company,

the one I'm running with Yanaina,

please welcome
an academic philosopher.

He's the director for the Centre
of the Study of the Senses at the

University of London and used to
work with the food industry -

Professor Barry Smith!

APPLAUSE

Barry, I'm running this
big food company now.

How am I going to get people
to like my food products more?

Well, you don't just
want them to like it.

The food companies really try
to get people to want the food.

Now, I think most of us think
that wanting and liking are...

I use the words interchangeably.
Aren't they the same thing?

They're not the same. Wanting and
liking sound like the same thing

when you're talking about food,
but in fact they're different.

You like apples? I like apples.

But you don't want to keep eating
them after you've had one.

Well, I'm a two apple a day guy.

I'm happy with that. And that's it.

And I don't think about them
when I'm not eating.

But I think we all know
the experience of having a plate

of greasy chips and, by the end,
you don't really like them,

but you want to finish them.

That's wanting.
That's what we're aiming for.

OK. It's a business - that's
what I want people to do. Yeah.

How does this help?

OK, so how do companies get
us to want the food more?

First thing, make it softer.

OK. So what we're going to do
is talk about the food matrix.

Now, the food matrix is when
our food like your apple

there has a structure.

Let's pour all of this in -
exactly the same apple.

So you've got a lovely
peeled, cored, juicy apple.

Now we're going to liquidise it.

Let's see what we can do.
OK, here we go.

BLENDER WHIRS

You're pre-chewing your apple.

Is that a fair way of putting it?

That's exactly what I'm doing.

Let's see how we go.

I am going to pour out
some of this sludgy stuff,

and you are going to eat your apple.

Now, I can consume
much more quickly than you can.

You're still chewing.

I can just swallow the liquid.

So what that means is that I can get
the sugars of the fruit

into me much faster.
I can get the sugar hit.

Why is that good?

Well, that's good
because I can go on eating this

because I get the quick hit -

I don't process it quickly enough,
I'm still hungry.

I still want more.

Does this mean apple puree
is bad for us?

No, but it does show us
in that different form

that food processing has
an effect on human physiology.

I can consume sugars faster.

I go on wanting them longer.

So processing, it's not
necessarily good or bad,

but it does change the way our
bodies interact with food.

That's exactly right. OK.

We're going to want
to make soft food

that you can eat pretty quickly.

What other tricks might we
want to do to sell more food?

We may want to make food drier.

People don't like dry food generally.

Why would we do that?

Well, most natural foods
have got moisture in them,

and moisture is where the bugs are.

We can show you that
because we've got two burgers.

On the right-hand side,
we've got a home-made burger.

On the left side, we've got an
industrially processed-made burger.

Now, let's see how they decay.

Look at the home-made burger.

So this is over several weeks,
is it? Several weeks,

and it starts to decay.

The bacteria get in there
through the moisture.

And you wouldn't want to eat that,
would you?

This burger is... You'd almost
still be willing to eat it.

But hold on. We've all eaten

industrially processed burgers
before, and they don't taste dry.

They're not...
They don't taste desiccated.

So, if we've taken the moisture out
but we don't want them to taste dry,

we have to put in additives
and emulsifiers

to give them the mouthfeel we like.

So there's an illusion of wetness?
There's an illusion of wetness,

but we're also going to put
in some salt, more sugars,

some more emulsifiers.

We're going to get it
just to be so delicious.

OK, so the burger is still
tasting wet and good,

but it lasts for a long time.

And then it seems like
it's got a lot of energy left.

We haven't taken out any energy.

We've just taken out the water.

But you've compacted the energy.

These industrially processed
burgers, without all that moisture,

they're energy dense.

What does that mean?

It means there's more
calorie per mouthful.

And that, again,
means you're eating too fast

to tell yourself that you're full,

that you should stop eating,

that you've had enough,
but you're not going to slow down.

So we've got that system
we've seen evolve on the timeline

that tells us
you've had enough food now,

but, when we consume these new foods,

it's no longer able to say,
you've had enough.

That's right. OK, that makes sense.

Now, what if Yanaina and I
want to really go global

and start using cheaper
ingredients and selling...?

Making more money, basically.

So we want to think of a product
which is very cheap to make,

has cheap ingredients.

Ready made ingredients.

So, let's try a drink.

We want the cheapest,
the most available

ingredient that goes into a drink.

What would it be?

Water.

Water.

Exactly right.

So, Chris, to make
the water more desirable,

we're going to put in the equivalent
of seven heaped spoonfuls of sugar.

So that is around three times more

than I would add to a cup of tea
or coffee of this size.

That feels like... Three or four
times? What's up with you?!

It adds... It's way...

I'm going to try this.

It's way too sweet.
It's way too sweet.

This isn't going to work.
No-one's going to buy this.

OK. So you know it's too sweet

and that's going to stop
you from drinking it.

So we'll fix that
because we'll add some sourness.

So here are some
citric acid crystals.

Try that. OK.

And lots of these drinks do have
acids in them. They absolutely do.

It's become a little bit
more refreshing. Good.

I'm not going to say it's nice.

It's fine. It's now drinkable,
but I'm not going to buy this.

You're not going to buy it because
it doesn't yet have a flavour.

So I'm going to
add this flavourant to it,

and you tell me
what that flavour is.

OK, give it a stir.

Who wants to smell...

Great! ..the drink? Great!
OK, tell us what you smell.

Orange. Orange.

The orange has it.
But it's citrusy, isn't it?

I'm getting kind of... I'm getting
quite a specific tangerine.

It's tangy, right?

OK. It's tangy.
It doesn't look great.

It doesn't look like
an orange drink. Right?

You wouldn't think
that was a great orange drink,

so let's give it some colour.

So here's a nice food dye I can add.

Et voila!

And is this ready...?

It's now not bad.

It's refreshing.

It's got a little sourness.

I believe there's
some orange in there.

It smells of orange.

Doesn't feel like this is...
I'm not sure I'd buy this.

So let's jazz it up a little bit.

What I'm now going to do is I'm
going to put some CO2 in here.

I'm going to make it fizzy.

So what does the CO2 do,

apart from wet the desk?

It suppresses the sweetness
and accentuates the sourness.

That's going to make it possible

to have those seven heaped spoonfuls
of sugar and find it palatable.

Try that. Mm!

And now it's become
quite an exciting product.

Is it ready for market?
Can we put it on the shelves?

Well, I think we have to decide
how we're going to deliver it

and, for that, we probably
want to put it in a can,

but we also want to
make it really cold.

Now, we'll put it in a can,

and we'll probably get people
to be excited

about what they're going to buy

by putting a nice big orange
on the front of the can.

Was the orange flavour
from an orange?

Er, no.

But if you look at
the small letters,

it says "orange flavour".

So is that allowed? We can...
We can get away with that?

We can. If you say so!
We can. OK, great.

So now people I think are
going to believe...

They're probably not going to
read that word, "flavoured".

It feels to me the interesting
thing about what you've done is

I've forgotten how much
sugar there is in this.

Absolutely.
You're smuggling it into me.

Yeah. So I'm bypassing the natural
system that you all have to say,

"That's too sweet,"

because I've used all sorts
of tricks to make it possible

for you to ingest that sugar.

More sugar than you
would usually take.

But why do I want to
give my customers

that massive dose of sugar?

Why not just make it a bit
less sweet in the first place?

Because if you like
drinking it like that,

and you get that big sugar rush,

you start craving that
and you'll go back for more.

Now, I also want to give you
another clue

about what's going to come next -
it's that lovely fizzy drink,

and that's the sound
of the can opening.

CAN CLICKS AND HISSES OPEN

And that's the noise that we hear...

The faces! I can see people going...

Yeah? You know that noise, right?

And what usually follows
that is, it's a big lug

and then an "ahhh".

My mouth is salivating.
I'm ready to go.

I've given you two cues.

I've given you the orange cue and
then the sound of the fizzy drink,

and your brain's
expecting something.

You've just had it

and, when you get what you expect,
the brain is very happy.

Barry, thank you very much indeed
for sharing all this. Pleasure.

Brilliant. Professor Barry Smith.

Now, what Barry has just done
is to ultra-process that water.

And this is a term - have you
heard the term ultra-processed food?

Right. There has been some debate
around ultra-processed food.

Many experts in the UK, including me,

agree that the main harms from
our diet, of which there are many,

they come from the fact
that we now eat too much

industrially processed food products
that are typically high in energy,

high in saturated fat,
high in sugar and high in salt.

And the best scientific evidence
shows that, if you eat a diet

high in these kind of foods,

then it causes health problems.

The most obvious is weight gain,

but there are lots of
other links to physical

and mental health problems too.

Now, there's lots
we still don't understand

about ultra-processed food, and I
think what's really important to say

here is that not all ultra-processed
food is equally harmful.

There's products like that
ice cream, confectionery, crisps,

lots of snacks,
that is obviously harmful.

We've known it's harmful
for a long time.

But then there are products
like fishfingers, lots of types

of baked beans, supermarket bread.

These are products - they're
ultra-processed, for the most part,

I eat them myself.

I feed them to my kids.

The thing to remember, though,
is that, whilst it's not

all equally harmful,

it is almost all high in calories,

saturated fat, salt and or sugar.

There's very little
ultra-processed food

that we can say is truly healthy.

And I would argue
that products like that

are not the foundation
of a healthy diet.

You might now all be expecting me
to tell you what to eat,

and I'm not going to do that.

The reason I don't tell
people what to eat

is because, for lots of
people in this country,

ultra-processed food is the
only available affordable food.

So what I'm interested in

is what the science tells us about
how to change the food environment

so that healthy food is more
affordable, more available,

and you can all make more informed,
true decisions

about the food that you buy and eat.

So I want to hear from you,

and some of you have sent in
pre-prepared questions.

The first question is from Marley.

Hi, Marley.

Do you want to read out
your question?

If you had to create
the ultimate superhero snack

that's good for the planet
and makes you feel awesome,

what would be in it?

Marley, I don't
have to create that snack.

Those snacks already exist.

Um... Bananas, carrots,
nuts, a glass of milk.

These are all really
good, healthy snacks.

They're part of what we call whole
foods or minimally processed foods.

But, Marley,
a brilliant first question.

Thank you very much.

APPLAUSE

OK, Sheila. We've got
a question from Sheila.

Hi, Sheila. Is there any food
that's never healthy to eat?

There's a lot of stuff in the world

that we think of
as being pretty harmful,

but, if you only do it
once in a while,

it doesn't do you any harm at all.

If you have a can of cola
once every couple of weeks,

it doesn't do your body very much
harm, we wouldn't worry about that.

The problem is that,
as Barry explained,

many of these food products
are engineered

so that you want them more
often than once a week -

in fact, you have them
on a Monday morning,

and then by Monday midday
you want them again,

and Monday evening, so that
for me is the difficulty.

We talk about things
being fine in moderation,

but that puts a burden on all of you

in the face of foods that
have often been engineered

by very, very sophisticated
teams of scientists,

and marketing teams, and these
foods are put in your eyeline

so they're very hard to avoid.

So, in general, I would say,
if you can be moderate,

there are no really terrible
things you should never eat,

but that is very, very hard
for a lot of people

and it's hard to be moderate.

Sheila, a brilliant question.

Next we've got Isaac. Where's Isaac?

Is it possible to feed the whole
world without ultra-processed foods?

So, this, Isaac, is at
the core of the discussion.

We've seen the massive efficiencies
of the industrial food system.

There's no question it produces food
that's very cheap and abundant,

but it isn't sustainable.

We throw away about 30%
of the food, OK?

Of all the food we produce.

So the system
is incredibly wasteful.

It is the leading cause
of plastic pollution.

It is the leading cause
of loss of biodiversity.

It is the leading cause
of deforestation.

OK?

The reason we cut down
tropical forest is to grow food,

and we feed most of that food
to animals.

OK? So we need a very, very
different food system.

And the way we start,
in my opinion, is with demand.

And that is what
these lectures are about.

I'm not going to
tell you what to eat

but, at the end of these lectures,

you might demand
slightly different food -

in your schools, from your shops.

The food industry
is incredibly smart and dynamic,

and they will be able to adapt

and produce different food
in a different way.

Now, over the course of these three
lectures, we have barely scraped

the surface of the food system,

and I want to end by throwing
the problem and the solutions

open to all of you.

You're going to become farmers,
scientists, chefs,

parents, teachers - all people who
deeply, deeply care about food.

Together, I think we can rediscover

the complexity and the diversity
of human diet, of human food.

And we will and can find new ways,

and redevelop old ways,

of feeding everyone affordably

and ways that support the
flourishing of all the other life

on Earth that we depend on.

Thank you all very
much for listening.

CHEERING AND APPLAUSE