01x01 - Episode 1

[bunniefuu]

[foghorn blows]

[wind whistling]

[alarm clock beeping]

[bright music playing]

[food sizzling]

- [man] You mix cheese in it?

- [man 2] I was gonna put a little bit.

- [man] When did you last have a burger?

- Last night.

[both laugh]

When we were kids, we ate hot dogs.

Sugary cereals.

- [toaster oven dings]

- [woman] Spam, bacon, lots of rice.

Top Ramen noodles.

That was one of the last things

I helped Mom in the kitchen with

- [both laugh]

- was making Top Ramen noodles.

[man 3] We are students.

We try to just keep food around

that we can quickly make.

We have

our Protein Plus drinks right here.

Gatorade with protein in it.

We also have these breakfast bowls

that we'll make quickly in the morning.

It takes, like, three and a half minutes.

[man 4] Meat pies, sausage rolls,

lamb curry, chicken curry.

- [woman] Mm.

- Yes.

Current diets and eating habits

- We have

- consist of, um

So, Wendy and I go [laughs]

To be honest

- Can I finish? You cut me off.

- Okay. Sorry.

Thank you.

[man] Everybody knows the average

American diet is not very healthy.

We sometimes call it

the Standard American Diet,

or S-A-D for "sad."

That's why, as a nutrition scientist,

I've tested many diets over the years,

looking for the healthiest ones.

A major challenge in nutrition studies

is that everyone is unique,

and individuals

respond differently to the same food.

So what if we got people

who are genetically the same?

Uh [laughs]

Identical twins

often have the same mannerisms.

They laugh in exactly the same way.

The way they hold their coffee or tea cups

or drinking beer, is extremely

- Ros Ros and I

- Well

specific to those twins.

Identical twins

are the perfect natural experiment

because each individual

has identical genes

in every cell of its body.

So they are the perfect way

to tell nature from nurture.

[Christopher] We're recruiting 21 pairs

of identical twins

with very different backgrounds

for this study.

We're gonna take advantage

of new technology and new methodology

that's gonna allow us to investigate

metabolism in a very comprehensive way,

and to show people the power

we have at the end of our forks.

[bright music continues]

[Christopher] Ladies and gentlemen,

we are ready for the orientation.

Come join us.

My name is Christopher Gardner.

I have a PhD in nutrition science.

I've been here for 30 years.

For many, many of those years

I've been feeding and bleeding people

for a living.

And recently, I started feeding,

bleeding, and pooping people

'cause now we are into the microbiome.

So, we have a very cool study,

and I wanna assure you that it's not like,

"Oh, we have a super cool diet,

and one of you has to do the lousy diet."

We've actually designed them to both

be positive impact on all of your health.

Okay, we're gonna,

for the first four weeks,

deliver food to you.

You're supposed to eat

just what we mail you.

For four weeks,

we've got a delivery service

that will be providing

all the food to the twins.

That means we'll know

exactly what they're eating

because we will have provided

all the food to them.

Then, for the last four weeks,

you're supposed to go cook on your own.

And this is less rigorous

'cause you won't be able to do it

as good as when we mailed it to you.

And after four weeks,

they're gonna make and buy their own food.

This is more like the real world,

when we don't have as much control

over that aspect of their lives.

The study aim here

is to investigate the impact of you guys

on these two different diets

for cardiovascular health,

metabolic status, and the gut microbiome.

And these two different diets will be

Are you ready?

Vegan versus omnivore.

High in fiber, high in probiotics,

high in phytochemicals,

high in antioxidants,

low in saturated fat.

The most recent nutrition research

suggests some benefits

to eating a plant-based diet,

but some nutrients,

like calcium, iron, and protein,

are easier to get from meat and dairy.

So for the next eight weeks,

we'll be investigating the pros and cons

of a healthy diet

that contains meat and dairy

versus a healthy diet

without either of them.

[Carolyn laughing]

That sounds like both lousy diets.

[laughter]

[Wendy] Pam is not as, you know

- Pam is not a very big meat person.

- [Pam] Yeah.

[Wendy] Where I, you know what,

if steak was not unhealthy

to consume every single day,

yes, I would be I would eat steak.

She would eat steak.

- Okay, this one is

- That one's the carrots. That's the beef.

[Pam] We're both chefs.

And we do corporate catering

and private catering.

[Wendy] I've never been

on a plant-based diet.

I've consumed, um,

like, you know, Impossible Burgers.

I've also never been

on a plant-based diet, but I think

Why you cutting me?

- Because you're not answering properly.

- I am answering it. You just wanna talk.

- You do it then.

- Okay. All right.

- Let's start again. All right.

- Okay.

[both chuckle]

[Christopher] Okay.

During these eight weeks,

we're gonna get some poop and blood.

That looks like stool, right?

[Rosalyn] I'm counting the times.

Two, four, six, seven, eight, nine.

Is that Did I count right?

- There's a lot of poop. Yeah.

- That is a lot.

- [Christopher] 'Cause it's at home.

- So you don't need two people for it?

Don't need two people?

- Just one person can do it.

- No Wait, now you're confusing me.

Two people?

- He doesn't have to be there.

- I mean, like, go like

[Christopher] Oh, no. You don't have

to be there to catch the poop.

[Charlie] Growing up

as identical twins was

I mean, I'm without a reference,

'cause I didn't grow up without one,

but what I can say is, we always

had somebody to play with.

Like, things like this.

"I need some time alone, you know?"

"I'm gonna go take a walk by myself.

Come on, Charlie. Let's go."

[chuckling]

[glasses clink]

[speaking in French]

[Charlie] We're known as the Cheese Twins.

We did work in cheese for a long time.

We ended up on The Great Food Truck Race.

We were also asked to do our own pilot.

I really enjoy touching cheese,

smelling cheese. Tasting it's great.

I don't think I'm gonna give up cheese.

[Christopher]

So, at the end of the week or so,

you guys are gonna be randomly assigned

these two different diets.

I want you to turn to your beloved sibling

and look them in the eye and say,

"Which one do I want least?"

"I know that's the one I'll get."

And if you're not prepared

to do the one you want the least,

you can't sign up for this study.

You can't switch later.

We're taking a comprehensive approach

to this study,

looking at body composition,

the epigenome, or biological clock,

the microbiome,

and the brain.

This study is unique 'cause no one's

really attempted this before,

to see whether we can really change

people's underlying biochemistry

in just eight weeks.

And the twin model

is the perfect way to do it.

So I'm super excited to see these results.

[foghorn blows]

[birds chirping]

[bright music playing]

- [Carolyn] This is one of my favorites.

- [Rosalyn] Even if it shows our underwear.

- [in Filipino] Undies are showing.

- [laughter]

[Carolyn, in English]

We were born in the Philippines.

Lived there until we immigrated

to the United States.

- Okay.

- [in Filipino] Okay. Give me the butter.

[in English] People think

that Filipino food is a lot of pork.

- No, well, that's here.

- A lot of pork.

- [Carolyn] Wait. We're making arroz caldo?

- [Rosalinda] Yeah.

[Carolyn] Pork, which seems ubiquitous

in the Filipino diet now,

at one time was prepared

maybe once or twice a year,

and that was a treat.

Processed foods were introduced

into the Philippine islands

around World w*r II.

So that's why, growing up,

we ate foods that were not part

of the Filipino person's diet.

As an immigrant,

there are so many health issues

in the Filipino-American community.

We have heart disease.

- Diabetes.

- Diabetes.

Something that I'm curious about,

how much are our diets part of that?

[Rosalyn] On this study, I was told

I shouldn't eat ice cream anyway.

[Carolyn] That sucks.

Everything in moderation,

and you'll be in good shape.

Well, I'm, I'm, I'm Team Omnivore, so

[Rosalyn] Yeah! Team Omni!

- [Markus] So I'm not for the plant thing.

- Whoo! Team Omni!

You don't wanna try

How about if it's good?

- [Markus] Uh-uh.

- No?

Yeah. Real meat is

That's why people make fake meat.

- Because real meat's good.

- [laughter]

So, for me, this study can help to also

motivate people to to change behavior.

[drive-thru attendant]

Hi. How may I help you?

[woman] There's this paradox

that I come up against, which is

[phone chimes]

we are excited to try new foods,

we're eager to see

what the best new restaurants are,

and then that we're also

stuck in our ways,

that the American diet is what it is,

and we can't change.

And, to me, only one of those is true.

[TV narrator 1] One of the most popular

and convenient foods in the world

is the American hot dog.

[Jennifer] But there's a history

in this country.

There's a cultural reason

for us to continue eating this way.

[TV narrator 2] What you really need

is food with protein in it.

Food like eggs and milk and fish and meat.

Remember my name, Protein.

[Christopher] To understand

a Standard American Diet,

you really have to go back

to sort of post-World w*r II,

where a lot of Americans

weren't qualifying for the military

'cause they were too thin.

They were undernourished.

And there was a huge push

to get enough calories out there,

be as efficient as we could.

We saw a growing availability

of convenience foods,

a lot of low-cost food,

which then started to morph

into more and more

processed and packaged foods.

[TV narrator 3]

Complete delicious dinners.

Taste pretty good?

Delicious. Like my own home cooking.

[Christopher] And we saw the same thing

with animal-sourced foods.

Beef, pork, chicken, eggs,

dairy products, cheese.

[TV narrator 4] Choose cheese.

The animal agriculture sector

industrialized

using a very production-line model.

And, over time, factory farms

took over to improve efficiency.

That decreased the cost of animal products

and greatly increased

the amount of animal products

entering into people's diets.

[man] The thought then was,

how can we make a cheap,

industrialized food system

to get people calories?

And that was what fixed our food system

the way it is right now.

And we're at a critical point that,

if we do not change,

this is going to affect us in ways

that many Americans don't imagine.

[Michael Greger] When the federal

dietary guidelines

come out with their "eat more" messaging,

they come out very clearly.

Dietary guidelines say,

"Eat more fruits and vegetables."

But what if you don't have access

to fruits and vegetables?

[Cory] You often see

these areas of America

where access to healthy fresh foods

is not available.

That's what creates food deserts.

[man] The first McDonald

that ever opened up in America

was in San Bernardino.

The people in San Bernardino,

like the rest of the country,

they eat

the regular Standard American Diet.

Lots of processed meats,

and lots of fat and oil.

And with diabetes,

heart disease, and dementia,

the numbers

are just astonishing and scary.

But five miles away,

right across Highway 10,

you have Loma Linda.

This population lives

more than a decade longer

and healthier than everyone else.

I just want to repeat that.

A decade longer.

And you live a decade healthier.

Why was that the case?

That was an enigma to me.

The environment is not much different.

They get the same water.

They get the same air.

But in Loma Linda, most of the population

has access to healthy foods,

such as vegetables, beans,

legumes, and fruits.

And because a lot of them

are Seventh-day Adventists,

the majority of them are vegetarians.

And even when they're not,

they eat meat sparingly.

Two areas just five miles apart,

and the biggest difference is food.

That's profound.

[airplane whooshing]

- [bright music playing]

- [birds chirping]

[Christopher] Today's an important day

of the study.

It's diet assignment day.

[Wendy] Ah, my little kidney donor.

[laughter]

It'll be interesting to see, like,

how these diets impact our growth.

[Rosalyn] What if one of us loses

a ton of weight and the other doesn't?

- That'll make us less twin-like.

- [Jevon] No more identical twinning.

[laughter]

All right. It's time for the diet

assignment randomization reveal.

- Okay, you're Carolyn, right?

- I'm Carolyn.

- Okay.

- Mm-hm.

You ready for this one?

Ah, I can taste the kale now.

[laughter]

[woman] Three, two, one.

- Activate!

- [drumming]

- Yeah!

- [cheering]

[applause]

- [Rosalyn] I feel relieved.

- [giggling]

[Rosalyn] I feel relieved.

I'm pretty excited.

I'm kind of feeling it for you though.

- Wa, wa, wa.

- But [laughing]

- [Pam] Who's next?

- [chuckling]

- [woman] Which one's Wendy? Pamela?

- I am.

[Wendy] I was really praying

that I'd be on the omnivore diet.

Omnivorous. Oh, omnivore diet. Yeah.

Shh.

I was hoping to be on the omnivorous diet,

only based on me being an evil twin

wanting to t*rture my sister.

- [woman] Okay, three, two, one.

- [drumming]

- Yes!

- Oh, no!

[laughter and applause]

Yes! Thank you, Jesus!

- No!

- [laughter]

[Pam] Being on two different diets

for the next eight weeks,

it's gonna be a challenge on me

based on the fact that

- it's not like my life stops.

- [Wendy] Exactly.

- My job continues.

- Yeah.

- And my job consists of making

- Chicken.

- Chicken. And

- Chicken curry.

I'm probably gonna catch myself

doing, like, putting meat,

and then probably having to spit it out

'cause I'm gonna remember,

like, "Oh, damn.

Okay, I'm not supposed to."

[Wendy laughs]

- Which of you is Jevon?

- [laughter]

That's you? Okay.

[Jevon] I've never been

on a plant-based diet.

And this is yours.

Chicken, definitely. [chuckles]

Steak. Love steak.

Every time I bring it up,

John's like, "Oh, I'll do either-or,"

but I do hope I get the plant-based diet.

I'd say I'm more excited than John is.

- [woman] All righty.

- [drumming]

Three, two, one.

- [ding]

- No!

[laughter and applause]

Oh my God.

- [Rosalyn] Oh, goodness. I just hope

- [Carolyn] They're both unhappy.

You were right.

We were gonna get the ones we didn't want.

[laughter]

And Charlie.

One of you

is about to not have cheese for a while.

- [drumming]

- Three, two, one.

- Hey! All right!

- Oh. Damn.

- That makes two.

- That's gonna be hard.

- Yeah.

- We both wanted

Giving up cheese for eight weeks,

that will be you know

It will feel, in my world,

like a bit of a sacrifice.

Like, I love cheese.

- [Pam] Wait, I'm confused.

- [Wendy] So he

I kind of wanted it,

but it's gonna be hard.

- [Pam] You wanted vegan?

- [Wendy] No, he wanted.

- Kind of.

- I wanted to try it.

- I did, but I didn't.

- Yeah.

[Wendy] I need my cheese.

- [laughter]

- I know. I know.

- [Wendy] I need my meat.

- [Michael] Someone's gonna

[woman] It's so interesting about cheese

that people can't give it up.

I meet people all the time who say,

"I would go vegan, except for the cheese."

[gentle piano music playing]

Growing up in Japan, we didn't eat dairy

because dairy was not a food

that Japanese ate.

In fact, the Japanese culture

has never had dairy in it

until after World w*r II.

The first time I had dairy products,

I remember that so well.

I was eight years old,

and it was a birthday party,

and they were going to have pizza.

And I thought, "If I eat this pizza,

I can finally become an American."

And I took a bite of this pizza,

and I was just like, "Oh my God."

It just was transformative.

Cheese is something

that speaks to the soul.

There's something romantic

about beautiful oozy Bries and Camemberts

that do something to you.

All I ever really wanted in life

was to be able to enjoy

a bottle of great wine

and some fancy cheese.

And a good baguette as well too.

The reason for that,

it's because it's biologically addicting.

Cheese actually

has something called casomorphin,

which is a hormone

that's released when casein,

which is milk protein,

breaks down in your body,

and it's a feel-good hormone.

So when you eat it,

somehow, you just feel high.

And that's why all milk

Apparently, even we have it

because it puts babies to sleep.

They're comforted. They feel good.

And it makes it really hard to give up.

The problem is that cheese

is full of saturated fat.

[Christopher] The saturated fat

that is found mostly in animal products

can raise levels of blood cholesterol

and clog your arteries.

And this can put you at risk

for diabetes and for heart disease.

[Michael Greger]

Too much dairy consumption, in general,

increases the risk of Parkinson's disease,

increases the risk of prostate cancer.

[cow moos]

This is why milk is meant for baby calves.

It's not meant for us.

Drink your milk, kids.

Well, Mr. Miller told me

he never drinks milk.

[woman] The dairy industry spent decades

trying to demonstrate dairy foods

were not only good for you

but were absolutely essential in the diet,

and that if you didn't eat dairy foods,

you weren't gonna be getting

enough calcium.

[narrator] Got milk?

[Marion] The milk mustache campaign.

That's the famous one.

They got celebrities,

sports figures, music figures,

to pose with the milk mustache,

and kids loved it.

[woman] If you think about it,

back when we were hunters and gatherers,

we had to find an animal

and hunt it down and k*ll it.

Dairy products weren't available.

And so I think that, you know,

this is what part of the problem is now,

that in our modern food society,

we have meat and dairy

in so many products,

and in the abundance

of which we're consuming it,

it's actually quite dangerous.

[Christopher] Americans have been

estimated to eat about 60 pounds of beef,

100 pounds of chicken,

and more than 650 pounds of dairy products

per person per year.

[Miyoko] It's really funny

that people think dairy is necessary

because most people in the world,

including Asians, are lactose intolerant.

Also, it's really interesting

because people today

think that we have to eat meat or dairy

to get protein.

But if you think about it

in the context of human history,

you'll find that most populations

did not eat meat or dairy

except in very, very small amounts,

if at all.

[footsteps approaching]

[John] My name is John. I'm 22.

[Jevon] My name is Jevon. I'm 22.

John has a very dark, rusty kind of voice.

- And I have this slightly nasally

- Bright.

- Brighter.

- Boyish.

- Bright. I won't say boyish, but, um

- [laughs]

I've been described as stoic,

um, quiet, a man of few words.

I'm definitely more quiet than Jevon.

[Jevon] In high school, people said

they were scared to come up to John

'cause of his face,

but they weren't scared to come up to me.

That's an interesting thing to say

to somebody who looks like that person.

- You know.

- [laughs]

I'm just laid back, I guess, is the

And mean-looking, apparently.

You know, they have a bruise

that looks like it's healed,

but another one on their

[Jevon] We're about to graduate

nursing school,

and we work with older people

who don't eat, you know,

the way they should,

and that's something

that it would be a good thing to change.

We do work out together.

Our dad has been a mentor.

He was a bodybuilder

back in, like, the '80s, '90s,

and he won a few competitions,

which is really cool.

[man] So we gotta pour

the whole thing in there?

- 80% of bodybuilding is diet.

- [food sizzling]

Basically, it's a high-protein,

high-carb, low-fat diet.

Don't they smell good?

- Yeah.

- [Jevon chuckles]

[John Sr.] I'm glad y'all ate

'cause y'all not getting any.

[laughter]

[Jevon] I have a short stature,

a very lean stature.

My friends still refer to me as skinny,

which is frustrating

because I've, you know,

put in almost four years of working out

to, you know, build myself the way I have.

I don't think

that I even have the appetite

to eat as much as I would need to to bulk.

[man] Wow, that's incredible.

Which one's your favorite pose?

[John] And on top of that,

I'll be eating vegan,

so getting enough protein

sounds pretty difficult.

[man] He was a really great poser.

You can tell by these shots.

That's awesome.

That's why I'm very excited

to work with a a trainer.

[man] My name is Nimai Delgado.

I am a professional bodybuilder

and health coach

that specializes in helping people

build muscle and lose fat

on a plant-based diet.

[announcer] physique champion, Nimai.

[man] Yeah!

I was born and raised

into a lacto-vegetarian family,

so I've never eaten meat.

There's been a strong push in the media

that has convinced people

that you cannot get adequate protein,

you cannot get adequate nutrition

without meat and dairy.

But there's been about 15,000 people

that have come through my programs,

and, about the two to three-week mark,

they'll start to noticeably feel different

in their energy levels,

in their ability

to get better quality sleep,

maybe even in their sex life.

But before the twins start

the actual training program

that I'm gonna give them,

we're gonna do tests

to measure their starting conditions.

- Okay, so, body-fat time.

- Okay.

- Yeah.

- You're up.

[birds chirping]

[Christopher] This is week zero,

or baseline testing,

and today, we are measuring

body weight and body composition.

We're not actually worried

about excess weight,

we're worried about excess body fat.

And there's ways to measure body fat.

[woman] We're gonna do a DEXA scan.

We're gonna measure your body fat,

your lean mass, and your bone density.

- What's my lean mass?

- Muscle.

I need you to remove your shoes.

The first test is called a DEXA scan.

And you're gonna breathe normally.

You do not have to hold your breath.

Please don't.

[Nimai] The DEXA scan

will be able to distinguish

how much muscle mass you have,

how much body fat you have,

and where it's distributed.

So a DEXA scan will be able

to accurately tell us how much muscle mass

each twin will be able to put on

and how much fat they'll be able to lose

in the course of this study.

[woman] When we stand on a bathroom scale,

we are not looking at fat and lean mass,

and we don't really understand

what the health ramifications

of having those things not in balance are.

If you don't have muscle,

you are unhealthy,

regardless of your pant size

or the scale weight.

So just breathe normally.

We'll start the scanner.

[device beeping]

[scanner whirring]

This device is going to measure

the twins' body composition

at the beginning

and at the end of the study.

And it will be a lot more accurate

than your BMI, or your Body Mass Index.

Typically, when I'm asked about BMI,

my blood pressure goes up.

So we'll, we'll, we'll stay calm.

BMI, or Body Mass Index,

looks at height and weight,

and it spits out sort of a health status.

This is a rudimentary way

in which we try to characterize

whether or not someone

is normal weight or overweight.

I personally don't like it

because it doesn't factor in muscle mass

or other features that are associated

with someone's body composition.

[Amy] If you have a six-foot,

250-pound bodybuilder

with 10% body fat,

by a BMI calculation,

they fall in the obese category.

A 120-pound female

that's nearly 40% body fat

would be normal.

That's why BMI is dogshit.

One important question

is where the fat is located.

If you have the right equipment,

and we do,

you can look at the difference

between body fat and visceral fat.

[Amy] Visceral fat is fat that lies

in and around the organs.

It's the dangerous fat.

And it increases your risk

for type 2 diabetes

and metabolic syndrome.

[Nimai] If you are consuming

high amounts of animal products

as well as processed foods,

you're getting trans and saturated fats,

which is going to increase your chances

of storing visceral fat

around your organs,

which puts you at risk for certain types

of cardiovascular disease.

[scanner whirring]

[Amy] I think the visceral fat

will be a really fascinating component.

How will different diets

affect visceral fat?

I don't know the answer,

and I'm anxious to find out.

[wind whistling]

[birds chirping]

[woman] Good morning.

I'll help you over here.

[Rosalyn] Oh, good morning.

[man] Jenny's gonna take you both

to height and weight.

- [Charlie] Okay.

- [man] Then you'll come in here.

We're gonna do

your blood pressure three times,

draw your blood,

you're gonna go pee in a cup.

- [twins] Okay.

- [man] Okay?

- [Pam] Okay, five pounds off.

- [Wendy] Okay.

[Pam laughing]

[scale beeps]

[Charlie] 212. Should I take off my pants?

'Cause this is

[laughter]

- [Michael] 212!

- [Charlie] That's way overboard.

[Christopher] The second set of tests

for the twins

will be measuring their cholesterol,

insulin, and glucose.

[man] Jevon, John.

It doesn't matter, you guys.

We'll also be measuring

their markers of inflammation.

That's related to immune function.

And the fascinating microbiome,

which is a really hot topic

in the health world right now.

The microbiome

is this complex community of microbes

that lives in our digestive tract.

For a long time,

we've actually known that our gut microbes

are fundamental to digestion of food,

but now we're finding out

that this microbial organ

is absolutely fundamental to our health.

[woman] How quickly you burn calories,

how quickly you fight off an infection,

whether you develop an allergy,

moods, behavior.

It'll be almost impossible

to find an aspect of your physiology

that is not touched

in some way by your microbiome.

[Justin] One of the big questions

in the field of microbiome research is,

"What is a healthy microbiome?"

[Tim] Our gut microbes,

they produce all the chemicals

that keep us alive

and make us live longer.

There are certain microbes

that are associated with unhealthy foods,

and there are others

that are associated with healthy foods,

and the ratio of these

is really important.

If we eat healthy foods,

we get more and more species,

more diversity.

You will actually acquire

a healthier gut microbiome.

[Erica] But the default diet

in our society

is foods that are devoid

of beneficial microbes,

and it's making us all very sick.

The really cool thing about twins

is that their microbiome,

while they're different from one another,

are more similar than non-twins.

- [man] Next stop is the bathroom.

- Woo-hoo!

And so to see how different diets

change the trajectory of this microbiome

that starts out in a similar place

Are you guys coming in?

will be the most exciting thing

to learn from this study.

Mike?

[Erica] What's gonna happen

if you don't take care of your microbiome?

Well, for example, within our colon,

we secrete mucus,

and it forms this barrier

that keeps our gut microbes

separate from our intestinal cells,

and this mucus lining

contains carbohydrates.

And so when there's

no plant-based carbohydrates

for these gut microbes to consume,

they start consuming the mucus lining.

So, in many ways,

if you don't eat plant carbohydrates,

your microbes actually start eating you.

[seagulls squawking]

- [Charlie] We gotta enjoy it. This is it.

- [Michael] I know.

Yeah.

Well, I mean,

nothing's changing for me, but

Yeah, that's true.

Smell this.

[sniffs]

[Charlie] Changing my diet,

it's gonna be a little challenging.

[sniffing]

From a health perspective,

it's gonna be great.

Eat more vegetables.

[Michael] Oh, it's melting.

[Charlie] But from an enjoyment

point of view,

maybe not as exciting?

[Charlie] Oh man.

- [Michael] Is it good?

- That's good.

[Michael] What do you think

the others are eating?

That's a good question.

[gentle piano music playing]

[sizzling]

[Nimai] A big concern of mine

is whether or not the twins

are going to actually

stay vegan.

It's a big ask

for somebody to go vegan overnight,

especially somebody that is not

willingly making this decision.

So we're making safari rice, right?

Yeah. We're gonna make safari rice.

- Okay. Perfect. Then I'm gonna make

- I miss my other knife that I lost.

[Pam] I know.

[Wendy] Today's dinner is more or less

telling our friends

that Madame Pam here is gonna be

vegan for eight weeks.

Yes.

We decided we're gonna go

- traditional South African.

- Yes.

[Wendy] South African food,

it's a melting pot

of Dutch, English, French

- German, because they're the ones

- Dutch. Not German. Dutch.

No, but we had the, the, the,

the German Huguenots.

We're not gonna argue.

- It was Dutch.

- French Huguenots taught us to make

It was the Dutch Huguenots

and the French Huguenots, Pam.

- Aren't they all the same?

- No.

- Oh, okay.

- No. No, no.

- [Pam] Is it smelling all right?

- [Wendy] Mm-hmm.

[Wendy] With us being

in the food industry,

a lot happened during Covid.

Boom.

Corporate catering came to a standstill

because people are working from home

versus working at the office.

- That one's good.

- [Wendy] Okay.

- [Wendy] We were forced to shut down.

- [Pam] Shut down.

And we started stress eating.

Yeah, so we started really stress eating.

I just developed this very unhealthy

relationship with food,

where I could eat ice cream

and, like, eat the whole

- Tub.

- Tub.

[Wendy] And we can start eating.

[woman] It's so pretty.

[Wendy] A lot happened during the past

two years that brought us to this point.

You know. You know I love cheese, right?

[Wendy] So this diet

came at the right time,

and I feel like it's gonna

kind of jumpstart

this healthy way

of thinking of food again.

[man] If you find out

this is healthier, would you go vegan?

- [woman 2] Ooh, interesting.

- [man 2] You see Pam.

She's gonna be

on the South African Olympic team.

[laughter]

[Christopher] With the twins

about to start their diets today,

an interesting new component

of the study to assess

will be the epigenome,

or biological clock.

[woman] Let's put on

your heart rate monitor.

Can you hold that there for me?

This is gonna stay on

for the next two tests.

[woman 2] This goes here.

I'll have you hold it.

And this goes over your head.

[woman 3] Epigenetics is often described

as the science

that explains why DNA is not destiny.

[man] Your body is made of DNA,

and that collection of DNA

is organized in a chain.

That is your genome

and is not really going to change.

Epigenetics, or the epigenome,

is the flags that control

how your genome is being read.

Unlike genetics, epigenetics is flexible.

This means that while we can't change

the genetic sequence,

we can change, through epigenetics,

the way we use our genes.

Nutrition is one of the most

powerful signals for our epigenome.

[woman] The idea of this test is,

you wanna go until you feel like,

"I'm gonna die if I go any further."

Because of good nutrition

and regular exercise,

you could be aging slower.

[device beeps]

This is the first study

looking at epigenetics, or biological age,

in identical twins.

Chronological age

is the number of years since birth,

whereas biological age

is the true age of our cells and tissues.

[Varun] If your biological age

is actually higher than the age

that is dependent on your date of birth,

that actually

has significant clinical implications.

- [woman] Done?

- [Pam] Yeah.

[Varun] You might be

higher at risk for diseases.

But the marks that we study,

they're not fixed.

They can be changed

based on different exposures.

[woman] Push.

[Varun] Things like diet, exercise

can allow you

to decrease your biological age.

That's where it was really interesting

for us to get into this project.

[woman] Fifteen more seconds.

Can you go to the next one? No?

I have to be honest.

I'm very skeptical that, in eight weeks,

you could change biological clock.

[woman] Done? Okay.

[Christopher] The work that I've seen

goes on for years,

and they don't see a change.

I really think this biological-clock thing

is a little far-fetched,

but it's a new area for me to look into,

and so it will be fun exploring this

with some new colleagues.

- [woman] How was that?

- [panting]

- That was something.

- [woman] Brutal? [laughs]

[Christopher] The last baseline test

we need to do

before the twins

start to change their diets in the study

is brain function.

[automated voice] Before you begin,

please make sure you are

seated comfortably in a quiet area.

Now you are going to move on

to the assessment.

We're very excited about this study,

especially the genetic aspect of things,

because people just assume

that Alzheimer's disease

is a genetic disease.

That if their parents

or their grandparents

had Alzheimer's disease,

that they're bound to develop it.

And that couldn't be

further from the truth.

[automated voice] Now touch the box

where you saw this pattern.

[computer chimes]

And where did you see this pattern?

[computer chimes]

You have completed the level.

- Yes!

- This time, there will be four

For Alzheimer's disease, only 3% of cases

have that kind of a genetic pattern,

where if they have the gene,

they will develop it.

In more than 90% of the cases,

lifestyle is what pushes

the manifestation of the disease.

[automated voice] Let's have a go now.

Press Good.

[Dean] What makes a processed-foods diet

a risk factor for dementia

is the fact

that it's laden with saturated fat,

it's laden with hormones,

and so many other chemicals

that we don't even measure.

And for the brain,

it's much more of a threat.

Remember, this is an organ

that's three pounds,

2% of our body's weight,

but consumes 25% of the body's energy.

That means it's working constantly.

It needs clean energy.

[computer chimes]

By reducing the kind of foods

that are laden by hormones

and other chemicals,

the brain will actually heal itself.

[computer chiming]

[automated voice] Well done.

You have completed the task.

I struggled with that one.

- [chuckling]

- [automated voice] Next, there will be

[Christopher] With baseline

data collection completed,

now we'll be able to find out

what measurable aspects of health

we'll be able to change

in just eight short weeks.

[Cory] So many people

in America in general

are dying from diet-related diseases,

and a lot of it is because

what we're putting in our mouth.

[cows mooing]

[man] 96% of all beef in this country

was, at some point,

in an industrial feedlot.

[pigs grunting]

[woman] All of the waste sits

until the farmer sprays the liquid

onto adjoining fields.

[woman 2] The grandkids,

they was coming in the house

saying it was raining outside,

and we was like, "No, it's not raining."

It was feces.

[Cory] Racial issues, economic issues.

[man 2] You know, when you see tumors

and you see bacterial infections,

kind of dadgum

ruins your appetite for chicken.

[Cory] Issues of climate change.

[cow mooing]

Why aren't we talking about this?

[Michael Greger] The good news is,

we have tremendous power.

People don't realize

that what we put in our mouths

is more important than anything else.

My first week.

[Ayesha] For us to be able to show

that, during this study,

twins who have the same genetic patterns

but they're exposed

to two different lifestyles,

can show differences

I'm very excited for a new change

and to see how my body transforms.

is a game-changer.

[gentle electronic music playing]