In this TEDxQUT talk, titled “Mathematics of Weight Loss”, Ruben Meerman, a reporter on ABC television’s Catalyst program and Play School’s first ever ‘resident scientist’, answers the question: When you lose weight, where does it go?
All right. Well I might get myself into a position here. And on the red carpet. I don’t think I need to introduce myself, do I? But this is the last talk for the day.
We will have a little bit of wrap up after this. And we’ll have a little time to reflect and maybe some questions. I know that some of you will want to get home. But let’s get cracking, because we’ve got about 12 minutes. My talk maybe might go for 15, so don’t panic if that thing goes over.
Here we go, the mathematics of weight loss. Well, let me start with this. Last year, I went surfing in Fiji. And the resort had a photographer following us around, taking photos. Which is really great, except that I couldn’t help but notice this.
Somehow, I’d managed to become five kilograms overweight. Couldn’t believe my eyes. So I did what they tell you to do, I ate less and I moved more. And within just three months, I discovered that I’d lost six kilograms. So then I did what a normal person does. I did physics, but anyone would do this. I graphed my weight.
And when I did the linear regression, I discovered that, lo and behold, on average I’d been losing 85 grams a day. Which got me thinking, in fact it got me very curious about this question that I’ve since discovered most people have no clue about. In fact they’ve never even thought about this.
And to prove my point, I’ve made a little video on Bondi Beach. And the question was this: When somebody loses weight, where does it go? What does it become? How does it get out of your body? You’re probably dumbstruck by the question.
These people were, so listen to this. Where does it go? Where does the weight go? Where does it go? Um. Um. Um. Well… Well… I don’t know. – I don’t know. That, I don’t know. I don’t have an answer for that. These are the mysteries of science. I have no idea.
I’d like to say into the ether. Into the ether? Ether? It gets used up. The universe. Another dimension. It doesn’t go anywhere.
When she loses it, it comes over to me. It becomes nothing. It doesn’t exist anymore I guess. That’s a very good question. Good question. What a fascinating question.
What would you say? It goes right in the crapper, mate. Sweat. Moisture. And sweat. It evaporates. Out of your ass. It’s poo. Ends up on Bondi Beach. That’s were it goes.
Well, basically, you burn it up as energy. You burn it as energy? Heat energy. Burnt. Energy. Burn it as energy.
So, what the heck is going on? We’re in the middle of an obesity epidemic. I don’t need to tell you about it. So why don’t these people know the answer to this fundamental question? Because not one of them was right. And we do know the answer.
This is not ground-breaking stuff I’m about to tell you. So let me just remind you of a few things you do know.
What’s the chemical formula for water? H2O. Chemical formula for carbon dioxide? You all know it. CO2. Right, so you know what human fat is made of. So what is the chemical formula for human fat? There is such a thing, believe it or not, it’s been known since the 60’s. It’s C55 H104 O6. That’s the chemical formula for the average fat molecule in a human body.
Some of the molecules might have a few more carbon atoms and hydrogen. Some might have less. They all have just six oxygen atoms. That’s very important and helpful for later. But this is the average fat molecule. C55 H104 O6.
So let’s be very clear about this. The difference between that…and that…is C55 H104 O6. I kid you not.
And the difference between that… and that? Same thing, C55 H104 O6.
So how does this stuff get out of a human body? Well, here’s the general equation. Looks pretty interesting, slightly complicated. Not if you’ve done some year-ten chemistry. Surely this is year ten chemistry. Well, it’s not, really. But here’s what it says.
Fat + oxygen => carbon dioxide and water.
That’s what it becomes. Biochemists have known this for ages. You inhale that. You exhale that. That’s what happened to it. Amazing.
Now that little arrow there is kind of oversimplifying something called Biochemistry. That’s three years at university. My apologies to the biochemists. I don’t mean to oversimplify. But I’m trying to get to the crunch. It’s really complicated. It doesn’t just come out of you for no reason. You’ve got to do stuff. Eat less, move more. We’ll come to that in a minute.
Look, when you lose weight, you want to lose kilograms. That’s all kilograms. All the stuff there. So why do people say heat? It burns up as energy. Because that’s what we’ve been telling them all this time. And it’s very confusing because energy has different units, kilojoules, or you might use calories. And yes, that’s heat. That’s motion, when you move. Or it’s thinking. Your brain needs energy. Or it’s growing. But that’s not where the fat goes.
So what are we talking about here? Let me just show you a couple more things. I’ve got some carbon dioxide here in its frozen form. We call it dry ice. It’s carbon dioxide. It has mass. The thing is you’re not used to seeing it. But here’s some dry ice. It’s heavy, and if you put it in water…Lo and behold, it does this cool thing and bubbles. You’ve all seen that before. That’s carbon dioxide and water.
That’s what fat is kind of made out of, but it’s not fat. I’m not making fat. That is not fat.
So, how does that become fat? Well it doesn’t, just like that. It becomes sugar first. Plants make fat. Well, they start the whole thing. A plant takes six molecules of carbon dioxide and six molecules of water, uses an amazing chemical called chlorophyll, holds them together and then sunlight comes in and binds those molecules together and that becomes sugar. C6 H12 O6 is glucose.
Fructose, same formula, C6 H12 O6. Sucrose is glucose plus fructose stuck together minus some H2O molecules. So it’s, do the maths…C29 H22 O5.
Well here’s some. This is sucrose. Plants make it. It’s this stuff joined together. It’s now got chemical energy holding these molecules together so they don’t just fly around like that. And by the way if you drink that 600 mil of lemon-flavored soft drink, you’ll get 17 teaspoons of this stuff in there. ‘ll just quickly show you what that looks like.
Here’s one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, right. So if you drink that, it’s the equivalent of doing what I just did with a spoon, except munching it all down. Exactly the same, no difference.
So if you do that, then what happens? Well, let me explain something else that I’ve been telling kids for a little while, and they get this. When you eat food, it’s not in your body straight away. If you swallow that sugar, it’s not in you yet. So, here’s a pool noodle with a hole running through it. And here’s an almond.
Now, if you put the almond in there, it can go all the way through and out the other end. Here’s another almond. If I put an almond in here, where’s the almond? You would say the almond is in the pool noodle. But is it the foam that the pool noodle is made of? No, of course not, it’s just in the hole that runs through it. That’s food.
You swallow food, it’s not in you. It’s in the hole that runs from here to the back door. Getting food into you is called digestion. So with this stuff, you’ve got to break the bond that’s holding the fructose to the glucose. And as soon as you do that, then that stuff can cross the barrier into your skin and into your body and then it can go around in your blood. That’s digestion, but it’s not metabolism yet. It’s got to go into your cells and then you’ve got to burn it up.
And if you don’t burn it up, if you eat all that sugar after you’ve had your three meals in the day, your body doesn’t waste it, it doesn’t come out here. The stuff that comes out the back door was never in you. Apart from a few molecules of cholesterol, it’s just fiber that you couldn’t digest plus the bacteria that live in your gut. You lose about 500 billion of those in one single sitting. They’re tiny. That’s many times the population of the Earth, every time you flush the toilet. It’s amazing. But that stuff was never really in you.
Here’s what happens if you don’t then metabolize that sugar. Well, then it’s going to get converted into the stuff that we all have a problem with fat. Now I’m just going to prove that you do breathe this stuff out. If you metabolize sugar you turn it back into carbon dioxide and water.
So…every time you exhale, out comes a bit of carbon dioxide. You can’t see it, this is the problem. This is why people don’t know how you lose weight. So, there you go, I’ve trapped some breath, I’ve inhaled that. Five percent of the air in there is now carbon dioxide, because it’s come out of my lungs. I’ve got some liquid nitrogen here, and I’m going to use that to freeze this air. Liquid nitrogen’s minus 196 degrees. Very handy. It’s right there.
In fact, I’ll just pour it straight on. So, be a little bit careful with this stuff, I use it all the time. If I look a little blasé, I don’t mean to. Please respect this stuff if you play with it. The way you would respect boiling hot water.
Now, if you pour it onto a balloon the balloon does not pop. Which is incredible. The nitrogen’s minus 196. Oxygen turns into a liquid at minus 183 degrees. So, the oxygen in the balloon is turning into liquid. Carbon dioxide turns solid. I’ve got a big bowl of it there. But it turns solid at minus 78 degrees.