When I was growing up, they told me, "Never play with fire."
Of course, safety first.
More calories, more fire.
Bananas.
Yes, yes.
Bananas!
Broccoli.
Dry that out.
Cheese puffs.
Yeah!
Yes. Yes!
Hello, welcome to the show.
I'm Bill Nye and I'm here to save the world.
And the world is trying to be healthier.
There are so many things involved in a healthy lifestyle.
So, sometimes we wanna take shortcuts.
A fad diet is a shortcut.
Food is fuel and we need energy to live.
The calories we see on food labels
aren't measures of how good or bad a food is for us,
a calorie is chemistry.
It's a measure of how much energy is in any type of food.
Take a look at this.
It's our charming...
Oh, yeah.
It's here. I got it, I got it. Yep. Oh, yeah.
...Albeit crude...
calorimeter.
A calorimeter, for those of you scoring along with us, measures calories.
So, what we can do with this remarkable setup...
Steady. Steady.
We're just gonna go with it.
Believe me, it's perfectly straight, it's just your imagination.
No. So, a food calorie... Spelled with a capital C.
...Is the amount of energy it takes to raise one liter of water
one degree Celsius. That's it.
It's a measure of heat energy.
It doesn't tell you whether or not the food is healthy,
or good for you, or bad for you.
It's just a measure of heat energy.
And as always, we...
Come on. It's Netflix. Let's burn something.
Yes.
In this case, a marshmallow.
You know, you guys, this just isn't effective.
We gotta throw fuel at the problem.
Oh, yeah.
That's what I'm talking about.
So, what happens is, the food energy is turned to heat
and the calorimeter measures that heat.
This is an illustration of how we measure food calories.
Generally in a sealed container called...
a bomb.
But we're doing it here to illustrate that food is fuel.
Now, for a long time, food energy was measured with calories,
spelled with an upper C.
That's the amount of energy needed to heat a liter of water one degree Celsius,
but that's been converted to joules.
J-O-U-L-E-S.
Named after our good friend, the physicist J.P. Joule,
who measured the relationship between mechanical work and heat energy.
This is not the singer, because nothing could measure her energy.
Now, people try counting calories and a million other things...
to lose weight, get healthy, gain muscle,
even to achieve some sort of hyper health,
but fad diets claim they can do all of this, and fast.
It doesn't help that trends in society,
what the ideal body looks like, change over time.
During World War II for example, skinny was considered unattractive.
We had fad diets that promoted gaining weight.
And yet, we still try them.
To get a better understanding of the reasons, we sent...
Karlie Kloss into the field.
Have you ever heard of a fad diet?
A fad diet?
- Fat diet? - A fad diet.
You mean, looking to lose 50 pounds,
instead of in three months you lose it in six days.
- You've never tried it? - Do I look like I need to be on a diet?
No. You look great. You look great.
Oh, my gosh. I've tried, like, everything.
I only ate veggies and drink waters for two months.
- Did you feel good while doing that? - So awful.
This is fun.
- I don't wanna get too sciencey... - Get sciencey. That's my jam.
The detox juices and stuff like that, usually they gain the weight back,
- sometimes more. - Yeah.
Because of the hormones that drive you... Drive your hunger.
One of the craziest ones is the blood-type diet.
The cabbage-soup diet.
The paleo. That's just straight-up meat.
Cucumber and milk.
Three dates a day.
Three dates a day is not a lot.
Very unhealthy.
You eat...?
- Everything and anything. - Me, too.
I am eight feet tall, but that is purely genetics.
Eight and a half.
Halt, please. No, can I ask you one question?
A friend of mine was on a sniff diet.
Instead of having dessert, they would open the bag of doughnuts,
sniff it, close it, and feel content.
I... That doesn't work for me.
- No. No, no. - No.
You lose one pound a day.
- Drinking this tea? - Correct.
Sounds like the next fad diet.
My friend and I were like, "We'll do the cotton-ball diet."
- Did you swallow cotton balls? - Yeah. I only had, like, two.
I was like, "This is nasty and this doesn't feel right."
That sounds like a successful fad diet.
In Mexico, they have this patch, it gets sewn onto your tongue.
When it's sewn on there you can't swallow food, only liquids.
As soon as I started eating regular food, the weight came back.
- I gained it back. - You don't see results.
- It comes right back. - Exactly.
It all kind of came back, and I think I actually gained more weight.
I try to eat as normal as possible.
- Smart. - Pizza, french fries, all that stuff.
- That's my diet. - That's the college diet.
- Yeah, that's my diet right now. - I like it. Respect.
They're incredible.
It's great.
You met some people with this thing on your minds.
Yeah, this kind of idea of a fad diet.
- People hear from their best friend... - "We'll get it done fast."
- they can lose ten pounds in a week. - All I need are cotton balls.
Or juices, or, you know, only drink...
- You know... - Carrot Juice.
- Yeah. Or there's crazy things... - With cotton balls.
I mean, people come up with just about anything,
and I think there's not a lot of science that backs these fads,
that backs these crazy ideas.
And that's why the results aren't always what you're hoping for.
And also, everybody's different.
So, something that might work for one person
definitely isn't gonna work across the board.
Now, of course it's none of our business, but did you ever get caught up in dieting?
I think that... I mean, I'm a girl, above all.
Like, I am a model, but I am a girl first and foremost,
and so I care about my body.
I wanna eat healthy. I wanna be aware of what I'm putting in my body.
- You're saying guys don't care about...? - I don't know. Maybe.
You have to tell me your perspective.
But I think that people want to know
about how to best fuel themselves.
Because at the end of the day,
- the scientific understand... - It's fuel.
- Food is fuel, right? - Yes. It burns.
- I was watching. It was... - I'm sorry. I was just thinking about...
I was having fun and then... It's all good.
I wish my... I wish my metabolism was that... fast.
Now, see, why do you wish that?
Because I really love food.
And I think that's the thing, is that people wanna enjoy food.
I think people have emotional relationships with food.
- I know I do. - I don't know what you mean.
You... Think about every holiday, every birthday.
Everything's based around, you know, meals,
and I think that's a great thing.
But there is this misunderstanding about that relationship.
And people wanna eat as much as they want
and they don't think about that food that they put in their body
as more than just something to indulge in.
It's actually energy.
- Look at the passion, wow. - I love food, if you can't tell.
Yeah. Yeah.
Thank you very much, Karlie.
- Thank you, Bill. - Blow it up.
So, to talk more about whether or not we have control
over our body size and shape,
please join me with my panel of experts.
Tonight we have...
Sara Benincasa, comedian and insightful person.
- Thank you. Thank you. - Observer of the human condition.
Next, you may recognize Jennifer Widerstrom from Biggest Loser.
- Yup. - Although she is a winner.
Thank you.
And Traci Mann, a professor of psychology from the University of Minnesota.
That's right.
May I say, "Go, Vikings," briefly?
- Sure. - Cut.
And, "Go, Twins."
- But, you know, it was a tough year. - Cubs. Cubbies.
Let me just ask you this. You hear a lot of things.
How much of your size and shape is genetic?
Well, actually about 70 percent of your weight is heritable.
- That's almost three quarters. - Yeah.
Now, just to put that in perspective, 80 percent of your height is heritable.
So, the amount of your weight that's heritable is pretty extensive.
There's only a little wiggle room for other things to affect your weight.
Do you feel that same way,
that you just inherit your body size and that's that?
I think there's a predisposition based on your history,
the eating habits of family members and what's been brought through.
I was joking earlier, I'm a spitting image of my mom,
my sister's the spitting image of my dad, and we look nothing alike.
So, I think it is hereditary,
but there are ways to make your shape the best it can be.
I mean, you have some control over your body,
but I think it's not nearly as much control as people think it is,
and it's not nearly as much control as people hope it is.
I come from a small tribe of Oompa-Loompa shaped and sized humans.
- And I can say, it takes so much work... - I think we're related.
To modify that and to change it.
And so, for... What I've noticed in my own family
is that the biggest barrier to changing that in any way
is psychological.
It's not a lack of access to the ability to walk around the block,
it's not a lack of access to fresh fruits and vegetables.
Thankfully, we're fortunate that way. It's a psychological barrier.
It's the fear that you won't be good enough,
or the fear that you can't keep up the routine.
And I'm really curious about that, in my own life and for my family.
You don't keep up the routine 'cause you're afraid of keeping up the routine?
I think it's a fear of failure sometimes.
If you really tried, then you could really fail.
But if I don't try at all, it's like, "I wasn't really trying, so..."
- It lets you off the hook. - Yeah, and it's also the idea that,
well, maybe I should be able to transform my body completely.
It's this unrealistic notion
that I could be suddenly six feet tall and 110 pounds,
which is never going to happen.
So, I think sometimes we feel defeated.
Speaking on behalf of the layperson,
I think sometimes we feel defeated by these images that we see.
We think, "I can never be that, so why even try?"
I think people also beat themself up because
what most people can do is lose some weight...
On pretty much any diet, people can lose some weight.
But then, on pretty much any diet, the weight comes right back on.
So, what that means is when people lose weight,
they give the credit to the diet.
They say, "Weight Watchers worked for me," or whatever this thing is.
"Paleo worked for me."
But when the weight come on again, they blame themself.
I hear a lot about fad diets, right?
What is the blood-type diet?
Has anybody tried the blood-type diet?
Do you just, like...?
Is it like you're a vampire
and you drink blood and then you lose weight?
It's really close. I actually think Traci should handle this one.
Oh, I've never tried it, but it's crap, whatever it is.
- Yeah. - What do you mean?
I am O-positive. I'm very happy with it.
You have blood and it has a type,
but that doesn't mean you need a different diet.
What about cleansing?
And those are insane as well.
- "Insane." Insane. - I don't know where that idea came from.
- Tell us how you really feel, Traci. - I'm sorry.
It's also bananas to think that anyone...
Appropriately enough, bananas.
To think you could subsist on bananas, or just fruit, or just vegetable juice.
I mean, I know pretty much nothing about food science,
but I do know that when you remove the fiber from a fruit or vegetable,
you're shooting the glycemic index way up.
And if you come from a family like I do where we tend to experience everything
from hyperglycemia to type 2 diabetes, that's a bad thing.
That's not cleansing. That's damaging.
But there's all these diets... Paleo diet. What is the Paleo diet?
That's when you're supposed to eat only the things cavemen ate.
Because they were known to be so very healthy.
- Some of them lived to be 17. - Like, 30. Yeah.
- Exactly. Exactly. - Yeah.
- So... - Dying.
- There's nothing new in diet ever. - Dying.
Just bacon.
It's just the old ones repackaged. There's nothing new in diet.
So, you don't go for it?
Ah, not typically. I just stick to marshmallows and bonbons.
Oh, good.
Can you train yourself to this level of low body weight?
You're battling a very tough foe, which is biology.
Here's what happens when you lose weight.
Your body doesn't know you just want thinner thighs or a flatter stomach.
Your body, unfortunately, thinks you're starving to death.
And the good news is, it jumps in to save you
by changing all these biological things.
To save you. It changes your metabolism.
So, suddenly, eating the same amount of food that you ate when you lost weight,
you don't lose weight anymore.
So, it's trying to be nice to me?
Your... It's trying to save you, but it's...
I mean, thanks, but, you know, can we have a conversation?
Is there a way that I can talk to it and say, "Hey, maybe, not?"
I mean, you could choose death or you could choose regaining the weight.
Don't do the death thing right now. We gotta finish the show.
So, can you get perfect?
Is there a perfect...
uh, size and shape?
That's where it gets interesting. What is perfect?
Are you telling me what it is? Is a magazine cover gonna...?
I'm not telling you.
She looks great no matter what she's doing,
but for the rest of us, here's what's perfect.
I'll tell you what's perfect. You said it can't be done.
Here's what's perfect.
Whatever you weigh when you are eating a reasonably healthy diet
and engaging in a reasonable amount of exercise
and reducing the amount of stress you experience.
However you look when you do those things, is perfection for you.
I agree with that, but what the problem is...
We talk about fad diets, the ins and outs.
To me, why there's so much failure but also why there's so much attempt
is because people have hope.
Is this willpower against willpower?
- I wanna push back against this willpower. - Oh, I think so.
As a psychologist, that's maybe weird for me to say,
but I wanna push back on this motivation and willpower thing.
It's not about motivation.
If motivation was all it took to be thin, everybody would be thin.
There's nobody more motivated than an obese person trying to lose weight.
It's not about motivation.
Let's push back on willpower.
It's also not about willpower.
Everybody blames their willpower when they have trouble losing weight.
Everybody thinks they have not enough self-control.
Everyone thinks this.
Nobody has enough self-control.
The problem with willpower is, unless it's perfect,
it's not really a very useful strategy.
If there's some M&M's right there, I'm trying to resist them.
I resist them now, yay for me. That's great willpower.
That's a good thing to do.
I resist them now and I've displayed some impressive willpower,
but I'm not done, I'm not out of the woods, because I have to resist it...
I have to resist it now, and two minutes from now,
and three minutes from now, and every time I notice them.
And they're getting closer and closer.
And the problem is,
I can display amazing willpower 20 times in a row,
on the 21st time if I take some and eat some...
- I've blown it. - Yes.
It erases all my perfect effort.
I think we have a different definition of what willpower and motivation means,
because I think motivation is exactly what keeps me showing up every day.
You said, "It's easy for you, you always look good."
This isn't an accident.
I wake up every day and I make choices that make me feel good.
Not for a waistline, but to feel good up here.
When I start eating M&M's, it's a dangerous neighborhood up here.
Everybody knows what I'm talking about.
You start to shame, you start to doubt your strength. Why?
If I want an M&M, that's fine. I'll work out. I'll pay for the party.
- Hey. - But the thing is...
No problem.
But the thing is some people could work out that much
and eat that little, and still not be...
Some people could work out that much and eat that little,
and still not look like you.
And that's the genetic thing. There's only so much you can change.
Can we just put a pin in this?
Can I have an M&M, please?
Thank you. Thank you very much.
- Opa!
No, it's fine. It's fine. This was planned.
This is great. A hand for the panel, everybody.
No, it was fantastic.
Enjoy the M&M's. Thank you, all.
A very popular fad diet is the Paleo diet, we spoke of it earlier,
where you eat like a cave person.
Now, my understanding is this cave person's name is Doug.
Doug, are you there?
What the...?
You think this is caveman music? Guys, cut the music.
You're right, you're right. Hey, guys, cut the music.
Say, Doug, I have a few questions about what you eat, your diet.
People in my time call it the Paleo diet. It's all the rage right now.
Uh, oh, right. Paleo diet. Okay.
Look, guys.
You have a diet based on what I eat.
Morons. Look at me. Do I look happy?
Is this really what you want to be?
The guy at the park who you usher your kids away from?
- It's not a good life. - Uh...
Right. Doug...
eating Paleo means giving up pasta and bread, carbohydrates.
Sacrificing carbs.
Our sacrifice was our daughter... Karen, to the sun.
Spoiler alert, it didn't work.
It still got cold that winter. We still had a few casualties.
I'm sorry, Doug.
But some people in my time think eating only protein
is inherently healthy.
This isn't healthy.
I'm being honest with you. I'm not healthy.
I'm 17.
Really? You're 17?
Does that surprise you?
It should, because I'm actually 13.
I just had my birthday last night.
Oh, uh, happy birthday.
Did you celebrate?
We hid in a cave, because there was a solar eclipse.
We didn't know what was going on.
Now, Doug, it isn't all bad, is it?
I mean, nobody has cancer.
Yeah, you guys have more cancer than we do,
but that's only because we don't live long enough to get cancer.
You know how I'm gonna die? When someone smashes my skull in
with an even more prehistoric skull that they find on the ground.
- That's how I'm gonna die. - Doug, I'm sorry.
That's awful.
But getting back to this diet.
What's your message to all these people
who swear by this meats, fruits and nuts thing?
Look, guys, if you want to eat like a caveman...
go ahead. Okay?
Go ahead. Be my guest. Go out there and find yourself a woolly mammoth...
slit its throat, bleed it dry, and then eat the raw meat.
Or you go to a sweet berry bush that looks really appetizing.
Are some of them poisonous?
Yes, they are.
Will you know which are which?
Not until you're dead.
Well, Doug, thanks.
We appreciate your insights.
Anything you'd like to add?
You guys, it's been real fun chatting with you.
If anyone wants to switch places, you know where to find me.
I'll be in my cave, where I sleep in the dirt.
It sucks.
You know, you guys, we really didn't go back in time.
It's Martin Starr from Silicon Valley. Give it up.
- That was fun. - He's a cave person.
As you've seen, a lot of these fad diets are chasing trends but not health.
But it's actually not that hard.
Even an elementary school student could explain.
Hi, hello. Can everyone hear me?
Welcome to the William Sanford Nye Elementary Spring Food Pageant.
Sometimes you grown-ups forget
that being healthy is a lot easier than you think.
I'll show you what I mean.
- Ready, cue cards? - Ready?
Don't talk.
Okay, music.
Action.
♪ Full of energy ♪
♪ And you burn it up ♪
♪ It's not to be avoided ♪
♪ Don't ever throw it up ♪
That was very sad. Bread, you're up.
Your mom's out there. Make her proud.
- I thought carbs were bad for people. - Just read what's on the cue cards.
♪ My name's Wheat Bread ♪
♪ And I'm a real good friend ♪
♪ I'm more than just carbs ♪
♪ You better comprehend ♪
♪ I've got tons of vitamins ♪
♪ For your blood and head... ♪
Wow, is that true?
♪ I get a bad rap ♪
♪ People think I make them fat ♪
Bread will slice you first.
Kale, your turn to shine.
But I'm on, uh, Gwyneth Paltrow's juice cleanse right now.
This ain't your show, superstar. Rein it in.
Fair enough.
♪ I got B vitamins ♪
♪ To help save the day ♪
♪ Keeps your liver from becoming ♪
♪ A big ashtray ♪
♪ But guess what, sweet pea? ♪
♪ There's more to me ♪
♪ I got a big junk load ♪
♪ Of vitamin C ♪
♪ To help boost your crappy ♪
♪ Immunity ♪
♪ So don't spit ♪
♪ Swallow me immediately ♪
Thanks. Thank you. Oh, my God.
Let's keep this going.
Eggplant. Gross, what are you doing?
Smoking. I'm stressed out.
We've talked about your attitude problem.
♪ My name is Eggplant ♪
♪ You may have heard of me ♪
♪ I'm a lot more useful ♪
♪ Than a sex emoji ♪
♪ I'm full of nasunin ♪
♪ The antioxidant ♪
♪ And my fiber keeps your butt From having accidents ♪
♪ Don't diss fruits and veggies In your fad diet spree ♪
♪ We're part of the key ♪
♪ To health harmony! ♪
Text me to your side piece.
♪ I'm beef ♪
♪ Everyone's favorite red meat ♪
♪ But you eat far too much of me ♪
Don't go raw.
Now you got it. Time for the big finale.
Cue cards, do it like Mr. Wizard would.
♪ It's common sense ♪
♪ Don't be so dense ♪
♪ Good health is easy If you follow these steps ♪
♪ Screw the fad diets ♪
♪ They're not in compliance ♪
♪ Detoxing is fake ♪
♪ That's just the science ♪
That was really fun.
Thank you to my guests...
Sara, Jen, Traci.
Now, go out there and sensibly save the world.
Thanks, you guys. Thank you.
Save the world, Bill.