The mathematics of weight loss | Ruben Meerman | TEDxQUT (edited version)

[Music] 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 will have a little time to to reflect and maybe some questions I know some of you will want to get home but let's get cracking because we've got about well probably 12 minutes is my talk maybe might go for 15 so don't panic if that thing goes over so 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 all these photos which was really great except that I couldn't help but notice this somehow I'd managed to become 5 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 I'd lost 6 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 well well I don't know I don't know that I don't know the mysteries of science it gets used up the universe another dimension doesn't go anywhere it comes over to me becomes nothing don't exist anymore I guess that's a very good question question what it fascinating question what would you say it goes right in the crapper mate sweat moisture and sweat evaporates up a Bondi Beach that's where I go well basically you burn it up as energy darkness is energy heat energy burnt in energy yeah you got me there I'm not quite sure mmm 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 groundbreaking 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 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 60s it's C 55 H 104 oh six 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 a few more 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 hate c55 hate 104 oh six so let's be very clear about this the difference between that and that is C 55 H 1 Oh 406 I kid you not the difference between that and that same thing c55 h1 Oh 406 so how does this stuff get out of a human body well here's the general equation looks pretty sort of interesting slightly complicated not if you've done some year 10 chemistry surely this is year 10 chemistry although well it's not really but here's what it says fat plus oxygen gives you carbon dioxide and water that's what it becomes and this biochemist have known this for ages you inhale that you exhale that that's what happens to it amazing now that little arrow there is kind of oversimplifying something called biochemistry that's three years at university and my apologies to the biochemist so that men doubt 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 what we'll come to that in a minute but look when you want to lose weight you want to lose kilograms that's all kilograms all that stuff there so what 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 well let me just show you a couple more things so I've got some carbon dioxide here in its frozen form we call it dry ice it's carbon dioxide it has mass thing is you're not used to seeing it but here's some dry ice and it's heavy and if you put it in water lo and behold it does this cool thing in bubbles like you've all seen that before well that's carbon dioxide in 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 finds those molecules together and it becomes sugar c6h12o6 is glucose fructose same formula c6h12o6 sucrose is glucose plus fructose stuck together - and h2o molecule so it's do the maths c20 no 12h 2205 right well here some this is sucrose plants make it and 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 are in there I'll just quickly show what that looks like here's 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 right so if you drink that it's the equivalent of doing what I just did with the spoon except munching it all down exactly the same no difference so if you do 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 so 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 right it's got a hole running through it and here's an almond and if we put the almond in there can go all the way through and out the other end whoop-dee-doo here's another almond if I put an almond in here is where's the almond you would say the almonds in the pool noodle okay but is it in 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 and getting food into you it's 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 or internal skin and into your body and then it can go around in your blood that's digestion but now 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 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 so 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 better just prove that you do breathe breathe this stuff out right 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 of traps and breath I've inhaled that 5% 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 is minus 196 very handy um where did I write that 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 blase I don't mean to it's 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 is minus 196 oxygen turns into a liquid at minus 183 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 so in the balloon now I have frozen well I have liquefied oxygen and frozen carbon dioxide I'm gonna take it out you'll see them so I'll just take a while for the balloon to go a little bit clear at the top the nitrogen in here air is 79% nitrogen the nitrogen is in the top of the balloon but now look at that liquid down there can you see that that's the oxygen from my breath that I hadn't used but once it's all gone there'll be some white powder left right the white powder is breakfast that's the carbon dioxide the carbon atoms I ate in the last 24 hours and when I blow on them they get warm enough to turn back into gas and they vanish and people think there's nothing in the balloon the balloon has mass those atoms have mass you can see carbon dioxide has mass when you solidified but when you breathe it out you don't see it and we've been confusing people by talking about kilojoules or calories and they're really important but people do not seem to understand that when you lose weight you're losing atoms you can't just turn atoms into nothing in fact science teachers out there you need to change the way you teach chemistry because those people and many in this room think that you can turn atoms into energy well it's one of the founding principles of modern chemistry you cannot turn an atom into pure energy it's called the conservation of mass before a reaction and after a reaction we teach kids you've got to have the same number of atoms it's called stoichiometry well we haven't been teaching it very well at all because people think you can turn fat which is kilograms into nothing or just kilojoules can't do it so he was my big fat question I'm a physicist I knew that bit but my question was if I've got 10 kilograms of this stuff then how much carbon dioxide does that become and how much water and turns out that that's really simple - this is year 10 chemistry and year 10 maths you need the periodic table of elements you have to look up hydrogen carbon and oxygen there they are now the periodic table has some important information on it the weight of a single atom of these elements so the weight of a single atom of carbon is twelve point zero zero one zero one one atomic mass units doesn't matter what they are in kilograms just yet I'll show you why in a minute we've got 55 of those in a average fat molecule so there's six hundred sixty point five nine what about the hydrogen okay there's a hundred and four of those so we have in one molecule of fat 104 point eight three atomic mass units okay great the oxygen is a little trickier this stumped me for quite some time in fact I rang around and I couldn't get a very clear answer on this because it doesn't seem that many biochemists have thought about it this way that's not because they're silly or whatever they just haven't thought about it in this way which really surprised me because this bit of information is the most motivating bit of information I had in my personal little journey of losing seventeen kilograms in six months it's all gone breathe it out amazing you could anyone can do this it's not hard so how much carbon dioxide and water well the oxygen is important there's six atoms of it in a molecule but what are they going to become are they gonna go out as carbon dioxide are they gonna go as water are they going some ratio of the two how do you figure this out took me ages and then the answer turned up in a very old paper from the 1940s where they'd taken water labelled the oxygen atoms made them put some an isotope of oxygen on to those and oxygen 18 gave it to mice the mice had it go in their belly but then it came out in their breath so water had the oxygen in it but then that oxygen turned up in the exhaled breath which showed that oxygen atoms are exchanged between carbon dioxide molecules and water molecules there's a really good reason for that here's some phenylthaline in water it's a bit hard to pronounce it's got a bit murky because I've left it sit but look if your barn here changes color great whoop-dee-doo what does it show you show you the carbon dioxide dissolves in water forms carbonic acid there's an exchange of oxygen atoms so what this told me is that the way these six atoms are going to leave your body is in the same ratio that they exist in the molecule so that's a two to one ratio so that means four will go out as carbon dioxide and two go it is water that's great now I know the answer so now you do the maths so we've got the first two answers I'm gonna add to the carbons the weight of four of these oxygen atoms they're gonna go out with carbon so check that up there and I've got two to go so two times that there we go check that with the hydrogen's because they're gonna go out with some hydrogen and now I can figure out the ratio of carbon dioxide and water from my fat so there's the totals and now we've just got to divide it by the total total and you get 84% will go out as carbon dioxide and 16% will go out as water so here's the answer then to my big fat question 84% of fat is exhaled 16% is excreted as water somehow it can be in your urine and your feces sweat that means that 10 kilograms of fat becomes eight point four kilograms of invisible gas that you breathe out that's amazing every time you're doing some exercise and your breathing rate goes up you're losing more weight than when you're sitting down and not breathing as rapidly and one point six kilograms will come out as water now we don't know if that comes out in your poo or in your where and your sweater in your tears because you cry a lot who knows but now I've got some frequently asked questions that I need to answer because there's lots of them well there's three main ones one can I just surround a breathe more everyone asks me straight away well you can't sit around and breathe more but it's called hyperventilation you've got a coax 4c 55 h1 Oh 406 out of the fat cells they're called adipocytes and to do it biochemistry made it amazing what really goes on it's a long story but you need to get them out by first of all moving more or eating less you've got to sort of starve yourself of energy so that you start turning these big molecules of fat they get broken into three fatty acids each they're called a triglyceride but they have to be broken apart before they can come out of the cells the hidey-holes that they live in in your bingo wings or you have double chins or your butter your muffin tops or wherever it is it's hanging around in there it's not going to come out until this hormone breaks them apart into its fatty acids it goes into your bloodstream and then you can oxidize them beta oxidation big long story really complicated amazing that we know but FAQ number two is does weight loss cause climate change well this is another really disturbing little thing because it means people don't understand climate change they just don't because if you did you wouldn't even think that but people think so why doesn't it cause climate change because food was made by plants just in the last couple of years and the way it did it was it took sunlight and glued water to carbon dioxide when you eat you're actually the energy is sunlight it was put there by the Sun if I wasn't well I'm not a hippie but I just about am because I think that this is amazing you eat sunlight that's the energy that you get but it's modern sunlight when you burn fossil fuels that's ancient sunlight it's locked up in the ground as carbon in wood Deadwood ancient fossilized coal and oil is ancient dead fossilized critters that lived in the sea that photosynthesize that died that got buried that eventually turned it all this does not cause climate change and the fact that people don't know that means we need to teach them more about climate change no wonder there are so many myths about both these things there are myths about weight loss there are so many diet gurus out there mate if they didn't know this are you gonna trust anything else they have to say to you no hopefully not stop buying their books that pills their rubbish why did you not know this until today I don't know the answer but it certainly makes me very very skeptical about any health claim that anyone makes who's supposedly a guru the third question that you don't get asked but I should get asked that I don't get asked at all except the biochemist would be sitting there wondering it right now did you take into account ketosis and no not really I did not ketosis is when you starve yourself of carbohydrates when there's no glucose in your blood and you can do this thing called ketogenesis your liver does it and can convert fat molecules into ketone bodies there acetone is one of them you go to a nail shop get your nail polish removed acetone right your body makes that stuff but you don't want to make it in huge quantities because you go into acidosis so I'm not going to comment on whether or not eating low protein diets is a good idea because I'm not an expert on that I would say that I'd be careful because it's linked to depression apparently in some papers I don't know I'm not making any health claims about low protein diets what I'm saying is that this is very simple if you just do what I did and what lots and lots and lots of other people I don't want to meddle it's easy all you have to do to lose weight is turn it into carbon dioxide and water and to do that all you have to do is eat less move more and keep reading thank you you

Channel: TEDx Talks

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Id: vuIlsN32WaE

Length: 21min 26sec (1286 seconds)

Published: Thu Oct 10 2013

Reddit Comments

[u/Tuttiflutes11]

This video is what convinced me that I could and would lose weight. It changed my life.

[u/tahlyn]

This is a repost (one I posted myself a while ago!) but I love some good scientifically sound sanity... so I'll allow it.

[u/CalcifersGhost]

Yeah this is a wonderful talk :) Totally threw me with that breathing thing too!

[u/npsimons]

I find myself wanting to link this video enough I feel it should go in the FAQ or wiki.

I like how you can lose weight by breathing faster, which coincidentally what happens when you exercise.