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We're doctors, brothers, and twins, and we both love to eat, | 0:00:02 | 0:00:05 | |
but which is worse for us - fat or sugar? | 0:00:05 | 0:00:09 | |
It's the hottest question in nutrition right now, | 0:00:13 | 0:00:16 | |
with sugar in particular being targeted as public enemy no 1. | 0:00:16 | 0:00:20 | |
Sugar is the thing that's making you specifically sick. | 0:00:21 | 0:00:25 | |
We're going to find out if too much sugar or too much fat | 0:00:27 | 0:00:30 | |
can make you sick or pile on the pounds. | 0:00:30 | 0:00:35 | |
You're a quarter fat! | 0:00:35 | 0:00:37 | |
One of us is going on an extreme high fat diet. | 0:00:39 | 0:00:43 | |
This is Tiger. Tiger is basically on my diet. | 0:00:43 | 0:00:46 | |
The other, on an extreme high sugar one. | 0:00:47 | 0:00:50 | |
None of these foods have any fat, do they? | 0:00:50 | 0:00:52 | |
It's a high-carb, sugary diet. | 0:00:52 | 0:00:54 | |
During these month-long diets, we'll be testing how our minds... | 0:00:56 | 0:01:00 | |
I bought loads of them! | 0:01:00 | 0:01:02 | |
..and our bodies cope with just eating fat or sugar. | 0:01:03 | 0:01:08 | |
I feel like I'm out of juice. | 0:01:08 | 0:01:09 | |
And what we discover is really surprising and really unsettling. | 0:01:09 | 0:01:13 | |
It overturns my entire way of how I think about my body. | 0:01:15 | 0:01:17 | |
I'm not well! | 0:01:17 | 0:01:19 | |
But after meeting this scientist | 0:01:22 | 0:01:23 | |
and some cheesecake-eating rats, we found that the latest | 0:01:23 | 0:01:27 | |
scientific research changed what we thought we knew about fat and sugar. | 0:01:27 | 0:01:34 | |
Total opposite of I think what we would expect, | 0:01:34 | 0:01:37 | |
what most doctors would expect, | 0:01:37 | 0:01:39 | |
what most people in the street would expect. | 0:01:39 | 0:01:41 | |
And it has the potential to do the same for you. | 0:01:43 | 0:01:46 | |
I'm Dr Chris van Tulleken, | 0:02:09 | 0:02:11 | |
and I'm a specialist in infectious disease. | 0:02:11 | 0:02:14 | |
Here in Britain, fat's traditionally been seen as the major problem. | 0:02:19 | 0:02:23 | |
When I trained as a doctor it was clear that fat was the enemy | 0:02:24 | 0:02:27 | |
because it raises your cholesterol | 0:02:27 | 0:02:29 | |
and it blocks up your arteries, causing strokes and heart attacks. | 0:02:29 | 0:02:32 | |
Over in America, it's sugar that's under attack. | 0:02:35 | 0:02:39 | |
I'm Dr Xand van Tulleken and my speciality is in tropical medicine. | 0:02:41 | 0:02:45 | |
Now, in the States, sugar isn't just regarded as unhealthy - | 0:02:52 | 0:02:55 | |
some people are even calling it toxic. | 0:02:55 | 0:02:57 | |
So, who's right? | 0:03:00 | 0:03:02 | |
It's a question that's fascinated us as doctors, and by a quirk | 0:03:02 | 0:03:07 | |
of birth, we have a head start in getting to grips with it. | 0:03:07 | 0:03:11 | |
Chris and I are identical twins, | 0:03:12 | 0:03:14 | |
which means we're genetically the same, | 0:03:14 | 0:03:16 | |
so we're in a really nice position to do an experiment on each other. | 0:03:16 | 0:03:20 | |
Now, I live in New York so I get constant messages | 0:03:20 | 0:03:23 | |
in the media about how fat is good for you and sugar is | 0:03:23 | 0:03:25 | |
really the enemy, so I'm going to go on a high fat, low sugar diet. | 0:03:25 | 0:03:30 | |
And although in Britain we do get this message, | 0:03:30 | 0:03:32 | |
it's not as pervasive, and I'm convinced if I go on a low fat, | 0:03:32 | 0:03:36 | |
high sugar diet, I will stay healthy. | 0:03:36 | 0:03:38 | |
So who's right? The Americans who think that sugar is really toxic? | 0:03:38 | 0:03:42 | |
Or the British, who think that fat is the deadly ingredient? | 0:03:42 | 0:03:45 | |
We're going on extreme diets based on the sort of techniques used | 0:03:52 | 0:03:55 | |
in scientific research, | 0:03:55 | 0:03:57 | |
although we are a rather unscientific sample of just two. | 0:03:57 | 0:04:01 | |
We want to know what they do to your weight and how | 0:04:03 | 0:04:05 | |
they affect lifestyle diseases like heart problems and diabetes. | 0:04:05 | 0:04:09 | |
Nutritionist Amanda Ursell is on hand to make sure | 0:04:10 | 0:04:13 | |
we get it right, and that it's edible. | 0:04:13 | 0:04:17 | |
If we kick off with Chris. | 0:04:17 | 0:04:19 | |
-Chris, you are on the high sugar diet. -Yeah. I can see that. | 0:04:19 | 0:04:21 | |
People tend to think of sugar as this, | 0:04:21 | 0:04:24 | |
the white stuff in the bowl, but actually all of this food | 0:04:24 | 0:04:27 | |
ultimately gets broken down into blood sugar. | 0:04:27 | 0:04:29 | |
So, you are allowed bread and bagels, pasta, rice, | 0:04:29 | 0:04:33 | |
potatoes, any description of breakfast cereals. | 0:04:33 | 0:04:35 | |
-And what's this? -That's, er, a fizzy drink. | 0:04:35 | 0:04:38 | |
And you can have some fruit and veg. | 0:04:38 | 0:04:40 | |
Well, you can have unlimited fruit and veg. | 0:04:40 | 0:04:42 | |
And they've all got sugar and none of these... these foods have any fat, do they? | 0:04:42 | 0:04:45 | |
It's designed to be very low fat and it's a high carb sugary diet, | 0:04:45 | 0:04:50 | |
and that's what you can live on for the next month. | 0:04:50 | 0:04:52 | |
For Xand, this is your bit here. | 0:04:52 | 0:04:54 | |
Basically, you can have cheese, you can have meat, you can | 0:04:54 | 0:04:58 | |
have steak, you can have burgers, it's chicken with the skin on, | 0:04:58 | 0:05:01 | |
you can have double cream in your coffee, you can have mayonnaise... | 0:05:01 | 0:05:04 | |
-The kind of thing you would do. -But you're not allowed any fruit, | 0:05:04 | 0:05:07 | |
and you're not allowed very much of this veggie stuff at all. | 0:05:07 | 0:05:09 | |
My problem is that I'm not going to have a poo for a month, am I? | 0:05:09 | 0:05:13 | |
Well, there are disadvantages. | 0:05:13 | 0:05:15 | |
Firstly, your girlfriend doesn't want to kiss you | 0:05:15 | 0:05:17 | |
because you have bad breath. | 0:05:17 | 0:05:18 | |
Constipation, yes, you're right. | 0:05:18 | 0:05:20 | |
I'm getting almost no fibre in any of this, am I? | 0:05:20 | 0:05:22 | |
Very limited fibre. | 0:05:22 | 0:05:23 | |
I think I'm going to be craving a bowl of fresh greens | 0:05:23 | 0:05:26 | |
by the end of a few days. | 0:05:26 | 0:05:28 | |
I'm sure you are. | 0:05:28 | 0:05:29 | |
What do you think, Xand? I mean, I feel like you got the better deal. | 0:05:35 | 0:05:37 | |
It's difficult cos I'm going to have bad breath | 0:05:37 | 0:05:39 | |
-and I'm not going to poo. -Mm. | 0:05:39 | 0:05:41 | |
But I get to have bacon and eggs for breakfast. | 0:05:41 | 0:05:43 | |
Just to be absolutely clear, we can both eat as much as we want | 0:05:43 | 0:05:47 | |
of the things on our bit of the table? | 0:05:47 | 0:05:49 | |
Yeah. That's what we want you to do. | 0:05:49 | 0:05:51 | |
These diaries are going to be quite hard to stick to, | 0:06:02 | 0:06:05 | |
so we're going to film them. | 0:06:05 | 0:06:06 | |
We're going to make video diaries using our phones. | 0:06:06 | 0:06:09 | |
So at least for the duration of the video diaries, Xand won't be able | 0:06:09 | 0:06:13 | |
to be shovelling carbohydrate into his mouth. | 0:06:13 | 0:06:15 | |
Just woken up, and what I feel like is a massive stack of pancakes, | 0:06:15 | 0:06:20 | |
with maple syrup. | 0:06:20 | 0:06:21 | |
The point is, if I have to tell into my phone every day | 0:06:21 | 0:06:25 | |
what the experience is, I can't lie. | 0:06:25 | 0:06:29 | |
-Keeps us honest. -Yeah. That's the plan. | 0:06:29 | 0:06:33 | |
What we're going to do now is sample how much oxygen your body consumes. | 0:06:33 | 0:06:36 | |
Food is, of course, the fuel that powers our bodies. | 0:06:41 | 0:06:44 | |
But just how it does that is subject to complex metabolic processes. | 0:06:44 | 0:06:50 | |
Dr Richard MacKenzie studies how these processes influence diseases like diabetes. | 0:06:53 | 0:06:59 | |
It's long been thought that eating too much fat can make us fatter, | 0:07:00 | 0:07:04 | |
and that saturated fat can raise our cholesterol. | 0:07:04 | 0:07:08 | |
High amounts of cholesterol are quite bad for us. | 0:07:08 | 0:07:10 | |
They block our arteries and that blocks blood supply | 0:07:10 | 0:07:14 | |
to the brain and heart, | 0:07:14 | 0:07:15 | |
so that's quite dangerous. | 0:07:15 | 0:07:17 | |
Eating or drinking sugar, on the other hand, releases insulin, | 0:07:17 | 0:07:21 | |
a hormone that regulates our blood sugar. | 0:07:21 | 0:07:24 | |
Eating too much sugar can make us fat, | 0:07:24 | 0:07:27 | |
and could potentially lead to diabetes. | 0:07:27 | 0:07:29 | |
We're going to be checking to see if our cholesterol and insulin levels | 0:07:30 | 0:07:34 | |
go up or down over the next month. | 0:07:34 | 0:07:37 | |
What's nice about this experiment, it's not a big experiment, | 0:07:37 | 0:07:40 | |
but we're well-controlled, | 0:07:40 | 0:07:42 | |
-and so we really should get a robust answer from this. -Yeah. | 0:07:42 | 0:07:46 | |
OK, gentlemen, what I need you to do is to pop behind the curtains | 0:07:46 | 0:07:49 | |
and strip down into your boxer shorts, please. | 0:07:49 | 0:07:53 | |
We're expecting these diets to have an impact on our bodies. | 0:07:53 | 0:07:57 | |
And one thing we're focusing on are changes not to just to fat, | 0:07:57 | 0:08:00 | |
but also to muscle. | 0:08:00 | 0:08:02 | |
Shifting fat is good, but losing muscle isn't healthy. | 0:08:04 | 0:08:07 | |
You do look very different to when I last saw you, | 0:08:07 | 0:08:09 | |
and I must look different as well. | 0:08:09 | 0:08:11 | |
Yeah, you've got a little bit fatter. | 0:08:11 | 0:08:14 | |
The first time in a few years we look a bit like twins. | 0:08:14 | 0:08:17 | |
OK, gents, we'll just go for the bod pod now, | 0:08:17 | 0:08:20 | |
I can see you're both a little cold. | 0:08:20 | 0:08:22 | |
It's freezing in here. | 0:08:22 | 0:08:23 | |
I feel a bit underdressed. | 0:08:23 | 0:08:25 | |
MACHINE: It is important to remove any jewellery, | 0:08:26 | 0:08:29 | |
shoes or eyeglasses before weighing. | 0:08:29 | 0:08:31 | |
Here we go. | 0:08:31 | 0:08:32 | |
Enter the bod pod, then close the door to begin test. | 0:08:32 | 0:08:36 | |
This machine measures the ratio of fat to muscle. | 0:08:39 | 0:08:43 | |
So Richard, we know that being fat isn't good for you, but why do | 0:08:43 | 0:08:46 | |
we need all this fancy equipment to measure it so precisely? | 0:08:46 | 0:08:50 | |
It's to help improve our understanding of exactly what | 0:08:50 | 0:08:53 | |
increased body fat is doing, and we know that it's | 0:08:53 | 0:08:57 | |
linked to a number of diseases that reduce our life expectancy. | 0:08:57 | 0:09:00 | |
So things like cancer, diabetes, heart disease, strokes, | 0:09:00 | 0:09:03 | |
hypertension, to name just a few, | 0:09:03 | 0:09:05 | |
all are related to an increase in body fat. | 0:09:05 | 0:09:08 | |
-It's the same noise as the Batmobile canopy coming out. -Mm. | 0:09:09 | 0:09:13 | |
Close the door to begin test. | 0:09:13 | 0:09:15 | |
And now we freeze him and send him into outer space. | 0:09:18 | 0:09:21 | |
Yeah, that's the plan. | 0:09:21 | 0:09:22 | |
So we've got the results from the body composition test. | 0:09:23 | 0:09:27 | |
So can we try and guess? Before you tell us, can we try and guess? | 0:09:27 | 0:09:29 | |
-Please do. -I think I'm 25%. | 0:09:29 | 0:09:33 | |
I feel like someone who almost a quarter of their body is fat, | 0:09:35 | 0:09:38 | |
that's how I feel. | 0:09:38 | 0:09:40 | |
You're pretty much spot-on, you're 26.7% body fat. | 0:09:42 | 0:09:47 | |
Spot-on, but slightly more than spot-on. | 0:09:47 | 0:09:49 | |
Good news for Chris is, he's 22% body fat. | 0:09:50 | 0:09:53 | |
Oh, so we're pretty similar. Oh, that's quite good, actually. | 0:09:53 | 0:09:56 | |
I mean I think, you know, there is going...you know, he... | 0:09:56 | 0:09:58 | |
-So am I overweight? -Um, well, we'd have to look at your BMI for that. | 0:09:58 | 0:10:02 | |
Don't pull the punch. Yes. | 0:10:02 | 0:10:04 | |
-A little. -You're a quarter fat! | 0:10:04 | 0:10:06 | |
-Look, Richard's being so nice about it! -"A little, | 0:10:06 | 0:10:10 | |
"I mean, we couldn't - we'd need to look at the chart." | 0:10:10 | 0:10:12 | |
All right, all right, I get the message, I get the message. | 0:10:12 | 0:10:15 | |
-And he's OK, is he? -A fraction over, | 0:10:15 | 0:10:16 | |
um, but certainly on the healthier side of 20, 22.6%. | 0:10:16 | 0:10:20 | |
I'm letting you down. | 0:10:20 | 0:10:21 | |
You're letting your genes down. | 0:10:21 | 0:10:23 | |
Yeah, sorry about that. | 0:10:23 | 0:10:25 | |
I'm eating a little piece of turkey rolled up in a piece of cheese. | 0:10:29 | 0:10:34 | |
I'm eating everything with my fingers now! | 0:10:34 | 0:10:37 | |
We're two weeks into the diets, and we now want to start | 0:10:43 | 0:10:46 | |
measuring how fat and sugar are affecting our bodies. | 0:10:46 | 0:10:49 | |
And the place we want to start is with our brains. | 0:10:53 | 0:10:57 | |
Everything goes through your brain, every decision you make, | 0:10:58 | 0:11:01 | |
every action you take. | 0:11:01 | 0:11:03 | |
So it'd be pretty important to know | 0:11:03 | 0:11:04 | |
if cutting out fat or sugar affected how well your brain worked. | 0:11:04 | 0:11:09 | |
At some point, we've all felt the pressure of mental stress | 0:11:20 | 0:11:23 | |
and tension, but how does what you eat effect how you deal with it? | 0:11:23 | 0:11:28 | |
And there are fewer more cognitively demanding environments | 0:11:31 | 0:11:35 | |
than a city day trading room. | 0:11:35 | 0:11:36 | |
So, we're going to put our diets to an extreme mental test | 0:11:39 | 0:11:43 | |
by becoming stock traders for the day. | 0:11:43 | 0:11:46 | |
Chris, on his high sugar diet, is in London, | 0:11:48 | 0:11:51 | |
and I'm on my high fat diet in New York. | 0:11:51 | 0:11:55 | |
So Chris, do you have any sense that you're going to be any good at this? | 0:11:56 | 0:12:00 | |
It is like the Matrix. | 0:12:00 | 0:12:02 | |
I'm looking at a financial horror show, this is just a mess. | 0:12:02 | 0:12:04 | |
I mean, no wonder the economy collapsed. | 0:12:04 | 0:12:06 | |
How could anyone understand? | 0:12:06 | 0:12:08 | |
OK, so that we have a bit of help, JJ is going to give us a hand, OK? | 0:12:08 | 0:12:12 | |
-JJ. -Hey, Chris, you've got to have a better attitude going in, buddy, | 0:12:12 | 0:12:15 | |
you're a smart guy, it's not that hard. | 0:12:15 | 0:12:17 | |
X axis, Y axis, it's... | 0:12:17 | 0:12:18 | |
It's buy high, sell low, yeah? | 0:12:18 | 0:12:21 | |
Er, buy low, sell high. | 0:12:21 | 0:12:23 | |
The other way. | 0:12:23 | 0:12:24 | |
OK, trade, and right there you see a bid. | 0:12:25 | 0:12:28 | |
After a quick lesson with JJ, we're let loose on US-based | 0:12:28 | 0:12:33 | |
TD Ameritrade's paper money application, and we've got | 0:12:33 | 0:12:37 | |
100,000 dollars of pretend money to play with. | 0:12:37 | 0:12:41 | |
Yeah. | 0:12:41 | 0:12:42 | |
It was a pleasure, guys. Chris, good luck. Xand, good luck. | 0:12:42 | 0:12:45 | |
May the best twin win. | 0:12:45 | 0:12:47 | |
-Right. -And thank you very much, fellas. | 0:12:47 | 0:12:50 | |
I can buy a bit of that. | 0:12:54 | 0:12:55 | |
I'm going to buy some more companies now. | 0:12:55 | 0:12:57 | |
I'm into it now. | 0:12:57 | 0:12:59 | |
Ten of oil, light sweet crude. | 0:12:59 | 0:13:02 | |
If the oil comes up then I will have made a bunch of money. | 0:13:02 | 0:13:07 | |
OK, so now the pressure's on cos I've spent all my money. | 0:13:09 | 0:13:12 | |
'Watching closely in the background is Professor Robin Kanarek. | 0:13:12 | 0:13:17 | |
'She studies the effects of diet on cognition, | 0:13:17 | 0:13:19 | |
'and she thinks I might be in for a hard time.' | 0:13:19 | 0:13:22 | |
Don't know what any of this means. | 0:13:25 | 0:13:27 | |
This is an extraordinarily difficult task because there's many | 0:13:27 | 0:13:31 | |
different aspects of cognition that have to be involved. | 0:13:31 | 0:13:35 | |
He has to first pay attention, then he has to remember what he's done. | 0:13:35 | 0:13:42 | |
What I can't remember is how many I bought and how many I sold. | 0:13:42 | 0:13:45 | |
And then he has to make decisions, | 0:13:45 | 0:13:47 | |
what we call executive processing, | 0:13:47 | 0:13:49 | |
he has to decide whether to buy or sell. | 0:13:49 | 0:13:52 | |
So he's got multiple things that are going on at the same time. | 0:13:52 | 0:13:55 | |
Oh, no, I bought loads of them. | 0:13:57 | 0:13:58 | |
See, now I've got negative money, | 0:14:01 | 0:14:03 | |
and no way of getting back out of the hole. | 0:14:03 | 0:14:06 | |
My problem is that being on a high fat diet could limit | 0:14:10 | 0:14:13 | |
the fuel for my brain. | 0:14:13 | 0:14:14 | |
I'm really stuck on this now. | 0:14:16 | 0:14:18 | |
Glucose is the primary fuel of the brain | 0:14:23 | 0:14:26 | |
and the best fuel for the brain. | 0:14:26 | 0:14:27 | |
Since he's been on a low carbohydrate diet, | 0:14:27 | 0:14:29 | |
almost eating no carbohydrates, | 0:14:29 | 0:14:32 | |
his stores of glucose in the body are going to be very low. | 0:14:32 | 0:14:35 | |
Um, and therefore I think as time goes on, he may be having | 0:14:36 | 0:14:39 | |
more difficulty with the task. | 0:14:39 | 0:14:42 | |
And I'm short of glucose on my extreme high fat diet. | 0:14:44 | 0:14:48 | |
But the body has a back-up plan. | 0:14:49 | 0:14:52 | |
It can turn fat into energy compounds called ketones, | 0:14:52 | 0:14:56 | |
but they aren't as efficient. | 0:14:56 | 0:14:58 | |
In normal everyday life, that's not a problem. | 0:14:59 | 0:15:03 | |
But when you need to think really hard, it can be. | 0:15:03 | 0:15:06 | |
I've got the initials in head and I can't remember what they stand for. | 0:15:07 | 0:15:11 | |
Then I've got to try and remember something about the companies. | 0:15:11 | 0:15:13 | |
The professor's research indicates that without enough carbohydrate | 0:15:15 | 0:15:19 | |
in your diet, your memory can be significantly compromised. | 0:15:19 | 0:15:23 | |
There are certain parts of the brain that use carbohydrates, particularly for memory, | 0:15:23 | 0:15:28 | |
and if they're aren't getting enough glucose, then they can not function properly. | 0:15:28 | 0:15:33 | |
Getting Exile at 97 dollars 29. | 0:15:36 | 0:15:39 | |
Over in London, things are markedly different. | 0:15:40 | 0:15:43 | |
Chris on his high sugar diet is more alert, has more energy, | 0:15:44 | 0:15:49 | |
and has a significantly better memory. | 0:15:49 | 0:15:51 | |
When I'm thinking hard I can really feel inside my head | 0:15:52 | 0:15:57 | |
brainwork going on, and this is very brain-heavy, | 0:15:57 | 0:15:59 | |
it's remembering loads of numbers, remembering loads of initials, | 0:15:59 | 0:16:02 | |
and learning a whole new language of bidding and asking. | 0:16:02 | 0:16:05 | |
So this screen means everything's going green | 0:16:05 | 0:16:07 | |
so everything's going up, so you just have to hope that continues. | 0:16:07 | 0:16:11 | |
I think I might be doing OK on my high sugar diet, | 0:16:13 | 0:16:16 | |
because the brain consumes 60% of the sugars in your blood. | 0:16:16 | 0:16:20 | |
For people who are on diets that have complex carbohydrates, | 0:16:20 | 0:16:24 | |
er, whole grains, fruits and vegetables, | 0:16:24 | 0:16:27 | |
there's a lot of studies that show at least on a short-term basis | 0:16:27 | 0:16:30 | |
that having a high carbohydrate diet will facilitate memory. | 0:16:30 | 0:16:35 | |
It's such fun. | 0:16:35 | 0:16:36 | |
I can see why these guys get really into it. | 0:16:37 | 0:16:40 | |
It's the end of the test, so who won? | 0:16:41 | 0:16:44 | |
I can't remember what I wanted to do, | 0:16:44 | 0:16:46 | |
let alone the numbers and letters I needed to do it. | 0:16:46 | 0:16:50 | |
I'm not cut out for this. | 0:16:50 | 0:16:51 | |
Maybe Chris'll have done better. | 0:16:51 | 0:16:54 | |
So Xand made...Xand made essentially 300 dollars profit | 0:16:54 | 0:16:57 | |
and I've made over 800 dollars profit. | 0:16:57 | 0:17:00 | |
So I absolutely thrashed him, | 0:17:00 | 0:17:02 | |
and I tell you what, I could not have done that if I'd been | 0:17:02 | 0:17:05 | |
feeling hungry or wanting something I couldn't have, like some sugar, | 0:17:05 | 0:17:09 | |
and a big carb breakfast is what meant I could do that. | 0:17:09 | 0:17:12 | |
Scientists are now beginning to understand how certain parts | 0:17:16 | 0:17:19 | |
of our memory are affected by carbohydrates. | 0:17:19 | 0:17:22 | |
On my high sugar diet I'm eating all kinds of carbs from starches | 0:17:25 | 0:17:28 | |
to grains, vegetables to fruit. | 0:17:28 | 0:17:30 | |
But no matter what form the carbohydrates come in, | 0:17:36 | 0:17:39 | |
it's all broken down in my gut | 0:17:39 | 0:17:41 | |
into single sugar molecules, like fructose or glucose. | 0:17:41 | 0:17:44 | |
And the effect of these molecules on our bodies | 0:17:51 | 0:17:53 | |
that's at the core of why some scientists, | 0:17:53 | 0:17:56 | |
particularly in America, argue that sugar's bad for you. | 0:17:56 | 0:17:59 | |
So Xand's in San Francisco, | 0:18:03 | 0:18:05 | |
to meet one of the researchers who's led the charge against sugar. | 0:18:05 | 0:18:09 | |
He's seeing Dr Robert Lustig, who's convinced that the way fructose | 0:18:16 | 0:18:20 | |
and glucose work in our bodies leads to all kinds of health problems. | 0:18:20 | 0:18:25 | |
Robert, do you want to pause in the doughnut store | 0:18:25 | 0:18:28 | |
-and get a bucket full? -I...I... We'll talk about it later. | 0:18:28 | 0:18:31 | |
For him, glucose and fructose are dangerous for different reasons. | 0:18:38 | 0:18:42 | |
First of all, fructose. | 0:18:43 | 0:18:46 | |
Turns out, only the liver can metabolise fructose, | 0:18:46 | 0:18:49 | |
and you have a limit to how much you can metabolise, just like any drug. | 0:18:49 | 0:18:54 | |
You have a threshold. | 0:18:54 | 0:18:57 | |
If you go over that threshold, your liver has no choice | 0:18:57 | 0:19:01 | |
but to take that extra energy that's been delivered to it | 0:19:01 | 0:19:04 | |
and turn it into liver fat, | 0:19:04 | 0:19:06 | |
because that's the way the way the liver gets rid of extra energy. | 0:19:06 | 0:19:09 | |
So you drink a bottle of soda, some of it you can metabolise, | 0:19:09 | 0:19:12 | |
but the rest of it has to become liver fat? | 0:19:12 | 0:19:14 | |
That's right. | 0:19:14 | 0:19:15 | |
And that liver fat can have damaging consequences for your health. | 0:19:19 | 0:19:23 | |
It can make you more liable to heart disease, strokes, or diabetes. | 0:19:23 | 0:19:27 | |
But according to Dr Lustig, that's just half the problem with sugar. | 0:19:29 | 0:19:33 | |
The glucose molecule activates insulin, | 0:19:35 | 0:19:37 | |
the hormone that controls blood sugar. | 0:19:37 | 0:19:40 | |
But Lustig believes insulin does a whole lot more. | 0:19:40 | 0:19:44 | |
Insulin shunts sugar to fat. The more insulin, the more fat. | 0:19:45 | 0:19:49 | |
Well, guess what? The more insulin, the more disease, too. | 0:19:49 | 0:19:53 | |
-OK. -And insulin is really the lynchpin in this whole story, | 0:19:53 | 0:19:58 | |
because whether you gain weight and whether you get sick | 0:19:58 | 0:20:01 | |
has everything to do with what your insulin does, | 0:20:01 | 0:20:04 | |
and if you can keep your insulin level down, | 0:20:04 | 0:20:07 | |
then you won't drive energy into fat, | 0:20:07 | 0:20:09 | |
you have a chance to lose weight, | 0:20:09 | 0:20:11 | |
you won't be making your arteries thicker, | 0:20:11 | 0:20:13 | |
you have a chance for your blood pressure to come down, | 0:20:13 | 0:20:15 | |
and this is what we've seen, | 0:20:15 | 0:20:17 | |
is, "it's the insulin, stupid." | 0:20:17 | 0:20:19 | |
It's known as the hormone hypothesis, | 0:20:20 | 0:20:23 | |
because fat cells respond to the release of insulin by holding | 0:20:23 | 0:20:27 | |
onto fat, and making more of it. | 0:20:27 | 0:20:30 | |
In general, the studies that support the theory about fructose | 0:20:39 | 0:20:42 | |
only looked at diets with unrealistically high levels of fructose. | 0:20:42 | 0:20:46 | |
Much more than the average person consumes. | 0:20:47 | 0:20:50 | |
So I'm not yet convinced about fructose. | 0:20:51 | 0:20:54 | |
And as for the insulin hypothesis, | 0:20:56 | 0:20:58 | |
the comprehensive study hasn't been done yet. | 0:20:58 | 0:21:01 | |
So like most scientists in Britain, | 0:21:01 | 0:21:04 | |
I'm pretty sceptical about these claims. | 0:21:04 | 0:21:06 | |
I'm three weeks into my high fat diet | 0:21:11 | 0:21:13 | |
and I'm really starting to miss carbohydrates. | 0:21:13 | 0:21:16 | |
I've got on the plane very early, | 0:21:17 | 0:21:21 | |
which means I can try and eat my burger quickly | 0:21:21 | 0:21:24 | |
before anyone sits next to me. | 0:21:24 | 0:21:25 | |
It's really hard not to eat the French fries. | 0:21:25 | 0:21:28 | |
So I'm all done. | 0:21:33 | 0:21:35 | |
This is what remains. | 0:21:35 | 0:21:37 | |
But even though I couldn't eat the carbs, | 0:21:44 | 0:21:46 | |
I wasn't ravenous after my meal. | 0:21:46 | 0:21:48 | |
What I really want to know is | 0:21:49 | 0:21:51 | |
if that has anything to do with the amount of fat in my diet? | 0:21:51 | 0:21:54 | |
To try and understand what's happening, | 0:22:03 | 0:22:05 | |
Xand has to fly back to Britain... | 0:22:05 | 0:22:07 | |
Right, boys. We want you to do something... | 0:22:09 | 0:22:12 | |
..where Amanda Ursell has set up what she calls | 0:22:12 | 0:22:15 | |
a hunger experiment. | 0:22:15 | 0:22:17 | |
We start the day eating the same amount of calories for breakfast. | 0:22:23 | 0:22:27 | |
Xand has a plateful of fat calories, but mine is chock full of sugar. | 0:22:33 | 0:22:37 | |
Three hours later, we're offered lunch. | 0:22:40 | 0:22:44 | |
And this is where it gets really interesting. | 0:22:46 | 0:22:49 | |
Because now, Amanda can test whether or not eating fat or sugar | 0:22:50 | 0:22:55 | |
has had any effect on how hungry we were. | 0:22:55 | 0:22:59 | |
Well, I'm jotting down what you're having, | 0:22:59 | 0:23:01 | |
so I'm going to count all the calories that you're going | 0:23:01 | 0:23:03 | |
to have, so I know exactly what's on the plate, so, there we are. | 0:23:03 | 0:23:06 | |
So will we eat the same number of calories like we did at breakfast? | 0:23:06 | 0:23:10 | |
-I'm going to start with this soup. -OK, the soup. | 0:23:10 | 0:23:14 | |
-Come on, come on. -Go on, then - off you go. | 0:23:14 | 0:23:18 | |
Start eating. I'm going to work all this out for you. | 0:23:18 | 0:23:22 | |
We both start hungry, but that doesn't last for long. | 0:23:22 | 0:23:27 | |
Do you think I'm going to be able to eat all that? | 0:23:31 | 0:23:33 | |
-No, no. -Delicious though this all looks, I'm not really enjoying it. | 0:23:33 | 0:23:37 | |
All right, what else can I have? | 0:23:39 | 0:23:41 | |
We've got some pasta. | 0:23:41 | 0:23:42 | |
-Pasta. -Yeah. | 0:23:42 | 0:23:44 | |
But is how hungry we feel just down to the calories we consume? | 0:23:44 | 0:23:48 | |
It's like I just don't want any more of that. | 0:23:52 | 0:23:55 | |
My brain has just said, "No, that's it, that's all you need." | 0:23:55 | 0:23:57 | |
-Can I take that? I need to measure what you've left. -Absolutely. | 0:23:57 | 0:24:01 | |
Or could it be the macronutrients in the meals, fat or sugar, | 0:24:02 | 0:24:07 | |
that are governing how hungry we feel? | 0:24:07 | 0:24:09 | |
-On this diet I can still eat to shame. -Really? | 0:24:10 | 0:24:14 | |
To the moment at which I hate myself more than I want to keep eating. | 0:24:14 | 0:24:18 | |
Can you get that whole meringue in your mouth at once? | 0:24:20 | 0:24:23 | |
So we've got the results now. | 0:24:30 | 0:24:31 | |
Later, Amanda gets busy with her calculator | 0:24:34 | 0:24:36 | |
and tots up the final calorie count. | 0:24:36 | 0:24:39 | |
OK, Xand, you're on the high fat diet, you had 825 calories. | 0:24:39 | 0:24:42 | |
-That's quite a lot. -Yes, that's a big meal. | 0:24:42 | 0:24:45 | |
Yeah, but you, Chris, on your carb blowout, you had, er 1,250 calories. | 0:24:45 | 0:24:49 | |
-Whoa! -That's...that's half your calories for the day right there. | 0:24:49 | 0:24:52 | |
-That's half my whole day's calories in a single sitting. -Yeah. | 0:24:52 | 0:24:55 | |
For me, the interesting thing is, I ate more food than you, | 0:24:55 | 0:24:59 | |
so calories do not necessarily make you feel full, | 0:24:59 | 0:25:02 | |
and I was then hungrier quicker, | 0:25:02 | 0:25:05 | |
so this really simple idea | 0:25:05 | 0:25:07 | |
that we kind of learn that if you feel hungry | 0:25:07 | 0:25:09 | |
you eat a meal and then you stop feeling hungry, | 0:25:09 | 0:25:12 | |
even that is not really true. | 0:25:12 | 0:25:14 | |
You can eat an enormous meal and end up being hungrier than the person | 0:25:14 | 0:25:17 | |
who ate...you know, you ate almost the number of calories I did. | 0:25:17 | 0:25:20 | |
What's going on there, then? Why is that? | 0:25:20 | 0:25:22 | |
There's quite a big body of research that suggests that | 0:25:22 | 0:25:24 | |
high protein diets make you feel fuller. | 0:25:24 | 0:25:26 | |
It's the protein that's making me feel full? | 0:25:26 | 0:25:28 | |
You don't really eat high fat on its own, | 0:25:28 | 0:25:30 | |
you don't eat butter on its own or glug down olive oil on its own. | 0:25:30 | 0:25:32 | |
Xand might. | 0:25:32 | 0:25:34 | |
It comes with protein and makes you feel fuller than the carbohydrates. | 0:25:34 | 0:25:37 | |
That's probably number 1. | 0:25:37 | 0:25:39 | |
But it's more than that. | 0:25:42 | 0:25:44 | |
Protein and sugar have very different effects on ghrelin | 0:25:44 | 0:25:47 | |
the hunger hormone. | 0:25:47 | 0:25:49 | |
The more ghrelin you have in your body, the hungrier you'll feel. | 0:25:49 | 0:25:54 | |
Protein suppresses ghrelin for longer than sugar. | 0:25:55 | 0:25:59 | |
The problem with sugar is that it's an easy source of calories, | 0:26:02 | 0:26:06 | |
and that can make you fat. | 0:26:06 | 0:26:08 | |
But you can end up eating fewer calories on a high fat diet | 0:26:09 | 0:26:13 | |
because of the interaction with ghrelin. | 0:26:13 | 0:26:16 | |
Not all fats are the same, | 0:26:18 | 0:26:20 | |
and fortunately on my diet I'm mostly on the good stuff. | 0:26:20 | 0:26:22 | |
I'm eating lots of monosaturated and polyunsaturated fats, | 0:26:22 | 0:26:26 | |
the kind of thing you find in eggs, olive oil, and oily fish. | 0:26:26 | 0:26:31 | |
And that's all good for you. | 0:26:31 | 0:26:33 | |
Now, I'm also eating quite a lot of saturated fat, | 0:26:33 | 0:26:35 | |
which is the kind of thing you find in foods like meat and cheese. | 0:26:35 | 0:26:39 | |
Now this stuff you're not recommended to have more | 0:26:39 | 0:26:41 | |
than 30 grams a day because it raises your LDL, | 0:26:41 | 0:26:44 | |
your bad cholesterol, but recently an increasing | 0:26:44 | 0:26:47 | |
number of scientists are saying this may not actually be true. | 0:26:47 | 0:26:50 | |
But there is no debate about trans fats. | 0:26:50 | 0:26:53 | |
Now, trans fats are found in a wide range of manufactured foods | 0:26:53 | 0:26:56 | |
like cakes and cookies, things like this, and they're not good for you. | 0:26:56 | 0:27:00 | |
And what they do is they not only raise your LDL, | 0:27:00 | 0:27:02 | |
your bad cholesterol, but they lower your HDL, your good cholesterol. | 0:27:02 | 0:27:07 | |
Fortunately, on my diet I'm not allowed to have any of them. | 0:27:07 | 0:27:10 | |
A gram of fat also has over twice as many calories as a gram of sugar. | 0:27:18 | 0:27:23 | |
And our bodies turn dietary fats into body fat more easily | 0:27:26 | 0:27:30 | |
than it does with sugar. | 0:27:30 | 0:27:32 | |
Ultimately, of course, fat and sugar are sources of energy. | 0:27:33 | 0:27:37 | |
So what we really want to know is how they work to fuel our bodies. | 0:27:38 | 0:27:43 | |
It's now going to get personal and painful. | 0:27:43 | 0:27:46 | |
What we're going to do is we'll have five minutes steady peddling away, | 0:27:48 | 0:27:52 | |
I'm going to talk to you, I want to keep a nice conversation going, | 0:27:52 | 0:27:55 | |
and then we're just going to start ramping it up a little bit. | 0:27:55 | 0:27:58 | |
We set up another test, this time on a bike. | 0:27:58 | 0:28:01 | |
This is very fun, I haven't used one of these before. | 0:28:02 | 0:28:05 | |
Have you not? Oh, you're going to hate it soon. | 0:28:05 | 0:28:07 | |
We've recruited Nigel Mitchell | 0:28:07 | 0:28:09 | |
from the first ever British Tour de France winning cycling team | 0:28:09 | 0:28:13 | |
to help us. | 0:28:13 | 0:28:14 | |
-Perfect, perfect, perfect. Just nice. -Keeping up so far. | 0:28:14 | 0:28:17 | |
This is the first exercise of any kind we've done in our diet, | 0:28:20 | 0:28:23 | |
and we've not eaten for 12 hours. | 0:28:23 | 0:28:26 | |
Your cadence looks nice. Drop a gear. | 0:28:26 | 0:28:29 | |
We're 15 minutes into an hour-long session. | 0:28:32 | 0:28:35 | |
Nigel wants to completely exhaust us. | 0:28:35 | 0:28:37 | |
-Ramp this up a little bit to 18mph now. -Drop a gear? -Drop a gear. | 0:28:39 | 0:28:43 | |
Yeah, we're starting to work a bit more now. | 0:28:45 | 0:28:47 | |
It's the first step in a particularly sadistic experiment, | 0:28:49 | 0:28:52 | |
to see if fat or sugar is the best macronutrient for exercise. | 0:28:52 | 0:28:56 | |
So, how much difference does the kind of nutrition science | 0:29:01 | 0:29:04 | |
you're doing make to a team? | 0:29:04 | 0:29:06 | |
I want to use foods to fuel them, | 0:29:06 | 0:29:08 | |
I want to use foods for them to recover. | 0:29:08 | 0:29:10 | |
So the foods that we give the guys | 0:29:10 | 0:29:12 | |
is a mixture of bars and gels and protein. | 0:29:12 | 0:29:15 | |
Breakfast, we use a lot of porridge. | 0:29:15 | 0:29:17 | |
Now you can't get porridge on the continent, | 0:29:17 | 0:29:19 | |
so for the Tour de France and all this we actually buy | 0:29:19 | 0:29:22 | |
the porridge oats in this country and we take them out there. | 0:29:22 | 0:29:25 | |
And last year it were about three weeks before the tour | 0:29:25 | 0:29:28 | |
and I go around my local supermarket | 0:29:28 | 0:29:30 | |
and I've got all my Sky kit on cos I'm working, and I've | 0:29:30 | 0:29:32 | |
got a trolley full of porridge oats, I've got about 80kg of trolley oats. | 0:29:32 | 0:29:36 | |
I put them on the conveyor belt and we take them through, | 0:29:36 | 0:29:39 | |
and the woman on the conveyor belt, | 0:29:39 | 0:29:41 | |
woman on the till just brings you down to Earth, she says, | 0:29:41 | 0:29:43 | |
said to me, "So do you work in a care home or something, you know, | 0:29:43 | 0:29:46 | |
"all this porridge oats that you've got?" | 0:29:46 | 0:29:48 | |
45 minutes in, Nigel takes a blood sample. | 0:29:53 | 0:29:56 | |
'The blood test confirm just how bad we feel. | 0:29:59 | 0:30:03 | |
'Chris is burning sugar like crazy and his blood sugar levels | 0:30:03 | 0:30:07 | |
'plummet from 4.7, where they were at the start of the test, to 2.7. | 0:30:07 | 0:30:11 | |
'I'm faring better. My blood sugar has fallen by only about 25%.' | 0:30:13 | 0:30:18 | |
This is doing exactly what we wanted it to do. | 0:30:22 | 0:30:25 | |
Last minute, then, boys. Just keep it like this. | 0:30:29 | 0:30:34 | |
'An hour of punishing exercise without food has pushed us to the | 0:30:34 | 0:30:38 | |
'edge of our physical capabilities.' | 0:30:38 | 0:30:39 | |
Yeah, I feel like I'm out of juice. | 0:30:42 | 0:30:44 | |
'We're now both exhausted and empty, | 0:30:49 | 0:30:51 | |
'which allows Nigel to test how fat and sugar fuel the body.' | 0:30:51 | 0:30:56 | |
OK, boys, so we've done the hour on the turbo trainers at the top, | 0:30:56 | 0:31:00 | |
we've pushed your blood sugars down, so you're just mild hypo... | 0:31:00 | 0:31:04 | |
Get off! What we're going to do now is race up the hill. | 0:31:04 | 0:31:08 | |
Now, we've got some food, so for Xander, we've got butter, | 0:31:08 | 0:31:12 | |
so it's one pack of butter, please. Just one. | 0:31:12 | 0:31:15 | |
And then I want you to take one in your pocket for eating | 0:31:15 | 0:31:18 | |
on the way up, and then we've got a gel for you. | 0:31:18 | 0:31:21 | |
-The same number of calories in the gel. -Roughly. | 0:31:21 | 0:31:24 | |
We've got the same number of calories in the gel as the butter. | 0:31:24 | 0:31:27 | |
But the gel is sugar. | 0:31:27 | 0:31:29 | |
'There's nothing special about either the butter or the gel. | 0:31:29 | 0:31:32 | |
'They're basically fat and sugar.' | 0:31:32 | 0:31:35 | |
So, right, I want you to ride at my pace. | 0:31:35 | 0:31:38 | |
I want us to control this, as we're going up there. | 0:31:38 | 0:31:41 | |
A little bit easier on the gears. That's it, perfect. | 0:31:41 | 0:31:44 | |
You're in the same gear. | 0:31:44 | 0:31:45 | |
'Now it's time for the race up the hill, between fat in red | 0:31:45 | 0:31:48 | |
'and sugar in blue.' | 0:31:48 | 0:31:50 | |
When we turn right, we're going to start just lifting it slightly. | 0:31:50 | 0:31:54 | |
-Are you OK? -Yeah, I'm all right. -Just push on a bit more, then. | 0:31:54 | 0:31:58 | |
'We're climbing the iconic and steep Box Hill in Surrey.' | 0:31:59 | 0:32:04 | |
'And in the next few seconds, | 0:32:04 | 0:32:06 | |
'it's going to turn into a fat versus sugar race to the summit.' | 0:32:06 | 0:32:10 | |
-What's your heart rates now, boys? -177. | 0:32:10 | 0:32:13 | |
154. | 0:32:13 | 0:32:15 | |
Just keep next to each other, if you can. | 0:32:15 | 0:32:18 | |
OK? Right, are you ready, both of you? Go! | 0:32:18 | 0:32:21 | |
Keep it going. Keep it going. | 0:32:24 | 0:32:27 | |
'In the race to the top, Chris soon speeds away from me.' | 0:32:31 | 0:32:34 | |
He just keeps getting further away | 0:32:38 | 0:32:40 | |
and I cannot make my legs go any faster. | 0:32:40 | 0:32:45 | |
It's like I'm stuck in one gear. | 0:32:45 | 0:32:48 | |
'With my heart rate pumping at 200 beats per minute, | 0:32:53 | 0:32:57 | |
I just manage to get to the top.' | 0:32:57 | 0:33:00 | |
Just looking at you two, you've got a big smile on your face. | 0:33:00 | 0:33:03 | |
You won the King of the Mountains there, Chris. | 0:33:03 | 0:33:06 | |
Xander, you bunked out. But this is the thing. | 0:33:06 | 0:33:09 | |
This is what we're trying to show. | 0:33:09 | 0:33:11 | |
When you're really trying to push it, your body needs the sugar. | 0:33:11 | 0:33:14 | |
It needs the carbohydrates. I want to measure the sugars again. | 0:33:14 | 0:33:18 | |
7.1, your blood sugar now. 7.1. | 0:33:21 | 0:33:24 | |
'Chris's blood sugars are so high because the sugar gel | 0:33:26 | 0:33:29 | |
'he consumed half an hour ago is still pulsing through his body. | 0:33:29 | 0:33:32 | |
'And that gave him the fuel to power his muscles up the hill. | 0:33:35 | 0:33:39 | |
'But what about my blood sugar levels?' | 0:33:40 | 0:33:44 | |
5.1, now that's interesting. | 0:33:44 | 0:33:46 | |
All we've given you to eat is fat and we can't convert fat into sugar. | 0:33:46 | 0:33:51 | |
'Completely deprived of glucose, | 0:33:51 | 0:33:54 | |
'our bodies have a dramatic way of making sugar. | 0:33:54 | 0:33:58 | |
'Protein in the form of muscle converts into amino acids, | 0:33:58 | 0:34:02 | |
'which are then turned into glucose | 0:34:02 | 0:34:04 | |
'and that's pumped into the blood, raising blood sugar levels. | 0:34:04 | 0:34:08 | |
'So there's no question you can power your body without sugar, | 0:34:13 | 0:34:17 | |
'but there is a price to pay.' | 0:34:17 | 0:34:19 | |
Your blood sugars going up has got to be coming from the protein. | 0:34:19 | 0:34:23 | |
He's burning muscle to make sugar. | 0:34:23 | 0:34:25 | |
-He's burning muscle to make sugar now. -I feel quite rubbish. | 0:34:25 | 0:34:29 | |
This is the last state you'd want one of your athletes to be in. | 0:34:29 | 0:34:32 | |
If we'd got one of our riders and they were in your state in the | 0:34:32 | 0:34:35 | |
Tour de France then I'd be looking for a new job. | 0:34:35 | 0:34:40 | |
So we had identical turbos, we've got identical bikes, we've got | 0:34:40 | 0:34:44 | |
the same tyre pressure, so you're doing the same work... | 0:34:44 | 0:34:47 | |
We've got effectively the same person. | 0:34:47 | 0:34:49 | |
Effectively the same person genetically. | 0:34:49 | 0:34:52 | |
The big difference is the diet that you've been following. | 0:34:52 | 0:34:56 | |
What's amazing about that is I haven't eaten any carbohydrate | 0:34:59 | 0:35:02 | |
in weeks and my body can still make enough sugar to get me up that hill. | 0:35:02 | 0:35:06 | |
How have you done this? | 0:35:06 | 0:35:08 | |
How have you turned your dreadful performance up that | 0:35:08 | 0:35:12 | |
-hill into a kind of victory for fat? -I got here, didn't I? | 0:35:12 | 0:35:16 | |
And... Yes, you did have normal carbohydrate, which is... | 0:35:16 | 0:35:19 | |
It's a point for me because your body needs carbohydrates to exercise like that. | 0:35:19 | 0:35:23 | |
And where are you getting the carbohydrate? From your muscles. | 0:35:23 | 0:35:27 | |
So you do exercise like that all day, you'll actually lose muscle and keep your little belly cos you're | 0:35:27 | 0:35:31 | |
-not turning that into carbs, are you? -All right. | 0:35:31 | 0:35:34 | |
I'll beat you on the way down. | 0:35:34 | 0:35:36 | |
-Yeah cos you're still fat! -HE CHUCKLES | 0:35:36 | 0:35:40 | |
This meal, it should be so good... | 0:35:52 | 0:35:55 | |
It's missing one essential ingredient. | 0:35:55 | 0:35:59 | |
And that's fat. | 0:36:01 | 0:36:02 | |
So it's totally joyless. | 0:36:02 | 0:36:04 | |
It's just a rubbish end to my day. | 0:36:04 | 0:36:06 | |
At last, the diets are over. | 0:36:12 | 0:36:15 | |
And we're back at the lab to find out what effect fat | 0:36:15 | 0:36:19 | |
and sugar have had on our weight and health. | 0:36:19 | 0:36:22 | |
OK, chaps. What I need you to do is get stripped off like before. | 0:36:23 | 0:36:27 | |
'We're with our old friend Richard McKenzie to be weighed and measured.' | 0:36:27 | 0:36:32 | |
OK, no talking, no moving. | 0:36:33 | 0:36:35 | |
'Starting, of course, with the machine that measures | 0:36:35 | 0:36:39 | |
'the percentage of fat and muscle in our bodies.' | 0:36:39 | 0:36:42 | |
OK, and you're up next. | 0:36:43 | 0:36:46 | |
'..Then close the door to begin tests.' | 0:36:46 | 0:36:50 | |
'And he's got some good news and unfortunately, some bad news for us, | 0:36:50 | 0:36:55 | |
'beginning with the results for the high sugar diet.' | 0:36:55 | 0:37:00 | |
-Chris, OK, you've lost 1kg of body mass. -Is that good? | 0:37:00 | 0:37:04 | |
You've been eating as much as you want of junk for a month | 0:37:04 | 0:37:09 | |
and you've lost a kilo. | 0:37:09 | 0:37:11 | |
Yeah, it's not bad. | 0:37:11 | 0:37:13 | |
Half of that has come from body fat | 0:37:13 | 0:37:15 | |
and the other half has come from muscle mass. | 0:37:15 | 0:37:18 | |
-Oh, really? So I have lost muscle as well? -Yes. -What about him? | 0:37:18 | 0:37:22 | |
-I feel like I've lost weight. -You have. | 0:37:22 | 0:37:25 | |
You've lost around 4kg of body mass. | 0:37:25 | 0:37:29 | |
'On the high fat diet, Xand has lost more weight. | 0:37:29 | 0:37:32 | |
'To be more accurate, 3.5 kilos in a month.' | 0:37:32 | 0:37:36 | |
So, where has that weight loss come from? | 0:37:36 | 0:37:38 | |
2kg has come from muscle mass, 1.5 has come from fat mass. | 0:37:38 | 0:37:42 | |
I've lost weight, which is great, | 0:37:42 | 0:37:44 | |
and I've lost a legitimate 1.5 kilos of fat. | 0:37:44 | 0:37:47 | |
In four weeks, that's really good. | 0:37:47 | 0:37:50 | |
On the face of it, that's very good. | 0:37:50 | 0:37:52 | |
Yeah, on the face of it, | 0:37:52 | 0:37:54 | |
but you've lost 1.5 kilos of fat and you've lost 2 kilos of muscle. | 0:37:54 | 0:37:58 | |
Your brother's right. We have to look at it in a bit more detail | 0:37:58 | 0:38:01 | |
and losing body weight is an ideal goal in some circumstances, | 0:38:01 | 0:38:05 | |
but you've lost 2kg of muscle mass and that isn't healthy. | 0:38:05 | 0:38:09 | |
Why is it so bad to have lost these 2 kilos of muscle? | 0:38:09 | 0:38:11 | |
If you lose muscle mass, with disease or ageing, | 0:38:11 | 0:38:15 | |
you are more likely to visit the hospital more often | 0:38:15 | 0:38:17 | |
and have a poor life expectancy. | 0:38:17 | 0:38:20 | |
-Really? -Yes. -That bad? -Yes. | 0:38:20 | 0:38:22 | |
That's a really important counterintuitive thing, | 0:38:22 | 0:38:25 | |
I think, that we're going to lose weight, go on a diet, we don't | 0:38:25 | 0:38:28 | |
think too much about exercise, and it can be really bad for you. | 0:38:28 | 0:38:32 | |
'Nervously, we went through the same battery of tests as we did | 0:38:39 | 0:38:43 | |
'a month ago. First, we checked our cholesterol.' | 0:38:43 | 0:38:48 | |
'We thought that because Xand was eating so much fat on his diet, | 0:38:48 | 0:38:51 | |
'his levels would be much higher. | 0:38:51 | 0:38:53 | |
'What was amazing is that they were nearly exactly | 0:38:53 | 0:38:56 | |
'the same as they were at the start of our diets. | 0:38:56 | 0:39:00 | |
'In fact, there was little or no change for either of us.' | 0:39:00 | 0:39:03 | |
One minute to finish. | 0:39:05 | 0:39:07 | |
'Finally, we tested our insulin, | 0:39:10 | 0:39:12 | |
'the hormone that regulates the level of sugar in your blood.' | 0:39:12 | 0:39:16 | |
Urgh! | 0:39:16 | 0:39:18 | |
'Naturally enough, on the high sugar diet, I went first.' | 0:39:18 | 0:39:23 | |
Your body's ability to produce insulin improved. | 0:39:23 | 0:39:27 | |
-That is the opposite... -Totally the opposite | 0:39:27 | 0:39:30 | |
of I think what we would expect, most doctors would expect, | 0:39:30 | 0:39:33 | |
what most people in the street would expect. | 0:39:33 | 0:39:37 | |
Probably just got used to dealing with the sugar, | 0:39:37 | 0:39:40 | |
the glucose intake and therefore, responding by producing insulin. | 0:39:40 | 0:39:44 | |
A bit like if I'd been drinking a lot for the month, | 0:39:44 | 0:39:47 | |
my liver would up-regulate the enzymes to deal with the alcohol. | 0:39:47 | 0:39:50 | |
It's almost the same thing. | 0:39:50 | 0:39:52 | |
Because I've been eating loads of sugar, | 0:39:52 | 0:39:55 | |
-I've become better at managing it. -You're better at producing insulin. | 0:39:55 | 0:39:59 | |
Is that good or not? | 0:39:59 | 0:40:01 | |
Um... | 0:40:01 | 0:40:03 | |
In the short term, it is good, but long term, | 0:40:03 | 0:40:05 | |
it might produce a problem. | 0:40:05 | 0:40:08 | |
'An unexpected result for me. | 0:40:08 | 0:40:11 | |
'But what about Xand on the high fat diet?' | 0:40:11 | 0:40:16 | |
What is worrying is your body is not responding to | 0:40:16 | 0:40:18 | |
insulin as well as it did. | 0:40:18 | 0:40:20 | |
If you eat too much fat, that can stop your body responding to | 0:40:20 | 0:40:25 | |
insulin and it also can tell your body to produce more glucose. | 0:40:25 | 0:40:29 | |
So how serious is this? It's only a month. Is this a big difference that you're seeing? | 0:40:29 | 0:40:33 | |
Actually, it is a big difference. | 0:40:33 | 0:40:35 | |
What we've seen is your blood glucose has climbed from 5.1, | 0:40:35 | 0:40:39 | |
which it was before the diet, which wasn't great to start with, | 0:40:39 | 0:40:43 | |
but still in a healthy range, to 5.9. | 0:40:43 | 0:40:47 | |
You're only 0.2 away from being pre-diabetic. | 0:40:47 | 0:40:51 | |
Wow! | 0:40:51 | 0:40:53 | |
In a month, I've done myself some proper damage. | 0:40:53 | 0:40:56 | |
-This isn't good for me at all. -It's not good for you. | 0:40:56 | 0:40:59 | |
That's the first thing. You should stop that diet. | 0:40:59 | 0:41:02 | |
Eventually, your body will stop producing insulin | 0:41:07 | 0:41:10 | |
if you carry on down this path. | 0:41:10 | 0:41:11 | |
I've been on a no-sugar diet | 0:41:11 | 0:41:13 | |
and I just would have thought I'd be making less insulin | 0:41:13 | 0:41:16 | |
and needing less insulin. You're saying I'm making more insulin, | 0:41:16 | 0:41:20 | |
my body isn't reacting to it as well | 0:41:20 | 0:41:22 | |
and I'm well down the road to diabetes, | 0:41:22 | 0:41:24 | |
which is, which is bad news. | 0:41:24 | 0:41:26 | |
It's bad news, you're heading that way. | 0:41:26 | 0:41:28 | |
So I thought if you eat lots of sugar, | 0:41:35 | 0:41:37 | |
you make lots of insulin and that's bad, | 0:41:37 | 0:41:39 | |
but it turns out me eating lots of fat makes my body insulin-resistant | 0:41:39 | 0:41:43 | |
so I make more insulin and that's worse. | 0:41:43 | 0:41:45 | |
So I'm...I'm doing really... | 0:41:45 | 0:41:47 | |
Like, I'm close to being diabetic now, I'm not...I'm not well! | 0:41:47 | 0:41:50 | |
I mean, was wrong too. Like I...so I thought, "Well, I'm having coffee, | 0:41:50 | 0:41:53 | |
"I can't have my cream in it, so I'll put in lots of sugar," | 0:41:53 | 0:41:55 | |
so I ate so much more sugar that I normally would... | 0:41:55 | 0:41:58 | |
-And I'd have thought that would make you diabetic or close to it. -That's...that's, I think we all, | 0:41:58 | 0:42:02 | |
that's the received wisdom of becoming diabetic is about eating sugar. | 0:42:02 | 0:42:05 | |
When are we ever going to learn that if you...it's never about one thing. | 0:42:05 | 0:42:09 | |
We say, "Oh, it must be fat or it must be sugar..." | 0:42:09 | 0:42:11 | |
No, it is ALWAYS more complicated than that. Always | 0:42:11 | 0:42:14 | |
It's like a really basic rule in life, isn't it? If someone | 0:42:14 | 0:42:17 | |
is selling you one simple solution to a problem that everyone has, | 0:42:17 | 0:42:20 | |
-it probably isn't going to work. -No. | 0:42:20 | 0:42:22 | |
As doctors, we know we have got to be careful | 0:42:39 | 0:42:42 | |
about extrapolating too much from our own experience. | 0:42:42 | 0:42:47 | |
Human physiology can be extremely complicated. | 0:42:47 | 0:42:50 | |
Being on a low-fat or a low-carb diet yourself, you learn all kinds | 0:42:58 | 0:43:02 | |
of things that you could never get from reading about it in a paper. | 0:43:02 | 0:43:05 | |
You learn about the experience of being on it, | 0:43:05 | 0:43:08 | |
whether or not it's fun, whether or not it's nasty, how it feels. | 0:43:08 | 0:43:12 | |
But the numbers that you get from an experiment | 0:43:12 | 0:43:14 | |
with just two people aren't definitive. | 0:43:14 | 0:43:17 | |
They're interesting, but they don't tell you enough. | 0:43:17 | 0:43:19 | |
To get definitive information from those numbers, | 0:43:19 | 0:43:22 | |
you have to look at the experiments | 0:43:22 | 0:43:24 | |
that are being done on thousands of people. | 0:43:24 | 0:43:27 | |
Over the last few years, | 0:43:35 | 0:43:37 | |
as the world's got fatter and more unhealthy, | 0:43:37 | 0:43:39 | |
finding an answer to the fat-versus-sugar question | 0:43:39 | 0:43:42 | |
has become even more pressing. | 0:43:42 | 0:43:43 | |
One of Britain's leading nutritionists, Professor Susan Jebb, | 0:43:51 | 0:43:55 | |
has been researching this for more than a decade. | 0:43:55 | 0:43:58 | |
And she started with a simple observation. | 0:43:58 | 0:44:01 | |
We've been looking at this for...for many years | 0:44:01 | 0:44:03 | |
and I guess what I struggle with is the idea that, | 0:44:03 | 0:44:06 | |
you know, people start off thin, or lean... | 0:44:06 | 0:44:09 | |
-Uh-huh. -..and at some point during their lives, | 0:44:09 | 0:44:12 | |
many people end up gaining weight, becoming fat... | 0:44:12 | 0:44:15 | |
This is me at the moment. | 0:44:15 | 0:44:16 | |
And a proportion of those go on to become sick and they develop | 0:44:16 | 0:44:19 | |
illnesses, like cardiovascular disease or...or diabetes. | 0:44:19 | 0:44:24 | |
We're in no doubt about this link, that being fat makes | 0:44:26 | 0:44:28 | |
a lot of people, not everyone, but a lot of people ill. | 0:44:28 | 0:44:31 | |
Absolutely, increases your risk of heart disease, | 0:44:31 | 0:44:34 | |
of cancer and of diabetes. | 0:44:34 | 0:44:35 | |
-OK. -So is it something about their diet which alters that risk? | 0:44:35 | 0:44:39 | |
We looked at um...at the amount of fat or carbs or indeed protein... | 0:44:39 | 0:44:46 | |
'So she set up a series of long-running, comprehensive studies | 0:44:46 | 0:44:50 | |
'to see what effects feeding people fat, | 0:44:50 | 0:44:53 | |
'sugar and protein had on their health and well-being.' | 0:44:53 | 0:44:56 | |
And more than that, we've tried to study the differences | 0:44:56 | 0:44:59 | |
in these groups, so we've been interested in saturated fat... | 0:44:59 | 0:45:03 | |
'She fed them bad fats - saturated fats, | 0:45:03 | 0:45:06 | |
'and good fats - monounsaturated fats. | 0:45:06 | 0:45:09 | |
'She did the same with carbohydrates, | 0:45:09 | 0:45:12 | |
'feeding people low and high GI, whole grains and refined grains.' | 0:45:12 | 0:45:15 | |
Maybe is about the fibre in the food or maybe is about sugar. | 0:45:18 | 0:45:22 | |
'For ten years, | 0:45:24 | 0:45:26 | |
'she conducted a series of detailed scientific studies | 0:45:26 | 0:45:29 | |
'into which was worst - fat or sugar.' | 0:45:29 | 0:45:33 | |
So I'm on tenterhooks, like, so what did you find? | 0:45:33 | 0:45:35 | |
You know, the changes that we got were important, | 0:45:35 | 0:45:39 | |
but they were quite modest. | 0:45:39 | 0:45:40 | |
They were surprisingly small, much smaller than I was anticipating. | 0:45:40 | 0:45:46 | |
And there are clear benefits | 0:45:46 | 0:45:48 | |
of a little bit more monounsaturated fats, | 0:45:48 | 0:45:51 | |
some benefits of low GI, some of more fibre, | 0:45:51 | 0:45:54 | |
but I really don't think we could say that a diet | 0:45:54 | 0:45:58 | |
which had some extreme composition was really a revolutionary answer. | 0:45:58 | 0:46:05 | |
What her study showed was that changing fat or sugar on their own | 0:46:08 | 0:46:13 | |
had a very small effect. | 0:46:13 | 0:46:14 | |
Especially when compared to the effect of losing or gaining weight. | 0:46:19 | 0:46:24 | |
So what is it that we're eating | 0:46:33 | 0:46:35 | |
that's making us fatter and unhealthier? | 0:46:35 | 0:46:38 | |
Unlikely as it may seem, the first clue in solving that puzzle | 0:46:38 | 0:46:43 | |
might lie in this tempting tray of doughnuts. | 0:46:43 | 0:46:46 | |
What I want you to do is look at this tray of doughnuts | 0:46:51 | 0:46:53 | |
and think about which one you'd choose if you could have any of them. | 0:46:53 | 0:46:57 | |
Got it? | 0:46:57 | 0:46:59 | |
Now, this is like a card trick, | 0:46:59 | 0:47:00 | |
I want you to remember the doughnut you chose and we're going to see | 0:47:00 | 0:47:03 | |
if the people in New York choose the same one as you. | 0:47:03 | 0:47:07 | |
All you have to do is choose a doughnut. | 0:47:07 | 0:47:09 | |
Ah, it's easy. | 0:47:09 | 0:47:11 | |
I'm going to find out if people in London | 0:47:18 | 0:47:20 | |
have the same taste in doughnuts as people in New York. | 0:47:20 | 0:47:23 | |
Right, do you want a free doughnut? | 0:47:23 | 0:47:26 | |
Er...I would like this one. | 0:47:26 | 0:47:28 | |
-The same one. -Yeah, yeah, yeah. | 0:47:28 | 0:47:29 | |
So can I offer you a doughnut? | 0:47:32 | 0:47:34 | |
Yeah, go for it, go for it, yes! | 0:47:34 | 0:47:37 | |
I'm on a diet. | 0:47:37 | 0:47:38 | |
XAND LAUGHS | 0:47:38 | 0:47:39 | |
-Is that good? -Yeah, it's good. | 0:47:41 | 0:47:42 | |
Everyone pick a doughnut. | 0:47:44 | 0:47:46 | |
-That's my favourite one. -Is it? -It's my favourite one as well. | 0:47:47 | 0:47:50 | |
You said that was your favourite one, why? | 0:47:52 | 0:47:54 | |
Just cos I've tried practically all of them | 0:47:55 | 0:47:57 | |
and I just like this one. | 0:47:57 | 0:47:59 | |
-Guys, thank you very much. -Thank you! -Enjoy your day! | 0:47:59 | 0:48:02 | |
So it's really interesting - all the glazed doughnuts have gone, | 0:48:02 | 0:48:04 | |
only one person picked the chocolate one. | 0:48:04 | 0:48:06 | |
Everyone seems to be going for the glazed ring. | 0:48:06 | 0:48:10 | |
Let's see if that continues. | 0:48:10 | 0:48:12 | |
'So why is that? What's so special about this particular doughnut? | 0:48:13 | 0:48:19 | |
'The doughnut preferences of Londoners and New Yorkers | 0:48:24 | 0:48:27 | |
'is in fact a clue to what we think is some of the most intriguing | 0:48:27 | 0:48:31 | |
'new science in nutrition. | 0:48:31 | 0:48:32 | |
'The real work is being done with rats and what they like eating. | 0:48:34 | 0:48:38 | |
'Everyday rodents who work with Professor Paul Kenny, | 0:48:40 | 0:48:43 | |
'a world-renowned researcher in the neurobiology of obesity | 0:48:43 | 0:48:47 | |
'and, rather interestingly, addiction. | 0:48:47 | 0:48:50 | |
'He devised a series of elegant experiments to work out | 0:48:50 | 0:48:54 | |
'what foods we like and why. | 0:48:54 | 0:48:55 | |
'The first thing he did was feed his rats sugar. | 0:48:58 | 0:49:00 | |
'And they could have as much as they wanted.' | 0:49:00 | 0:49:02 | |
The animals, of course, enjoy them and they'll consume vigorously, | 0:49:04 | 0:49:07 | |
but they tend not to gain weight, because what they do is | 0:49:07 | 0:49:10 | |
they adjust the consumption of other macronutrients to compensate. | 0:49:10 | 0:49:13 | |
So, on average, animals with access to high-sugar solutions | 0:49:13 | 0:49:17 | |
consumed the same amount of calories each day as they would | 0:49:17 | 0:49:20 | |
if they weren't having access to those solutions. | 0:49:20 | 0:49:22 | |
Really? So if you let a rat drink all the soda it wants to, | 0:49:22 | 0:49:26 | |
or you let it have unlimited access to sugar, it doesn't get fat? | 0:49:26 | 0:49:30 | |
Typically, no. | 0:49:30 | 0:49:32 | |
'Then, he gave them as much fatty food as they wanted.' | 0:49:32 | 0:49:36 | |
If you just give them access to fat, | 0:49:36 | 0:49:38 | |
they will gain some weight, but really not that much, | 0:49:38 | 0:49:40 | |
and what you find is they don't eat as much, physically eat as much | 0:49:40 | 0:49:44 | |
food as they would've before, the reason being | 0:49:44 | 0:49:46 | |
that they know that the fat is high in calories | 0:49:46 | 0:49:48 | |
and their body is quick to deal with that. | 0:49:48 | 0:49:50 | |
They have signals that tell them, "You've had enough, stop eating." | 0:49:50 | 0:49:54 | |
'And there's something simple you can do at home to get | 0:49:54 | 0:49:56 | |
'a sense of what Professor Kenny's been studying.' | 0:49:56 | 0:49:59 | |
This is double cream and it's thick, | 0:50:02 | 0:50:05 | |
it's luxurious, it's rich, | 0:50:05 | 0:50:08 | |
it's creamy... | 0:50:08 | 0:50:09 | |
..and it's really boring. | 0:50:12 | 0:50:14 | |
This is sugar. | 0:50:14 | 0:50:16 | |
After even with one mouthful, it's overpowering. | 0:50:23 | 0:50:29 | |
BUT if we mix them together... | 0:50:31 | 0:50:33 | |
Now, that stuff I could eat all day, | 0:50:42 | 0:50:44 | |
and in fact, we do eat this all the time, | 0:50:44 | 0:50:47 | |
cos basically, what we've just made is ice cream. | 0:50:47 | 0:50:50 | |
Now, this ice cream is absolutely delicious and the reason it tastes | 0:50:53 | 0:50:57 | |
so good is because the combination of fat and sugar is unbelievable. | 0:50:57 | 0:51:01 | |
Mm. | 0:51:03 | 0:51:04 | |
So, Professor Kenny took this simple insight | 0:51:07 | 0:51:10 | |
and fed his rats foods that were high in fat and sugar. | 0:51:10 | 0:51:14 | |
So what happened when you fed cheesecake to rats? | 0:51:14 | 0:51:17 | |
They practically stopped eating the regular, healthy food that | 0:51:17 | 0:51:21 | |
was there, but they didn't binge on the high fat, high sugar stuff, | 0:51:21 | 0:51:24 | |
they grazed on it, but that was their main source of calories. | 0:51:24 | 0:51:27 | |
This is the going to the fridge and just having a spoonful | 0:51:27 | 0:51:29 | |
-of ice cream every 20 minutes. -Precisely, yeah. | 0:51:29 | 0:51:31 | |
You know, you get up and you eat, but if you're going to eat | 0:51:31 | 0:51:34 | |
it's for that type of food and you tend to eat much more frequently. | 0:51:34 | 0:51:37 | |
You're not gorging on it, but that's what you eat continuously. | 0:51:37 | 0:51:39 | |
And those animals gained a massive amount of weight, | 0:51:39 | 0:51:42 | |
they really gained a lot of weight, and they became sedentary. | 0:51:42 | 0:51:45 | |
They slept a lot, didn't move around, | 0:51:45 | 0:51:46 | |
but that was where they got their calories from. | 0:51:46 | 0:51:48 | |
What Professor Kenny's discovered is that, | 0:51:51 | 0:51:54 | |
unlike fat and sugar on their own, | 0:51:54 | 0:51:56 | |
the rats had no off switch when it came to fat and sugar combined. | 0:51:56 | 0:52:00 | |
The combination of fat and sugar is completely different | 0:52:00 | 0:52:04 | |
than either macronutrient alone, and it tastes remarkably good. | 0:52:04 | 0:52:07 | |
And so what you have are these systems in the brain that are there | 0:52:10 | 0:52:14 | |
to respond to not whether you need food to live, | 0:52:14 | 0:52:16 | |
but whether you like using food, | 0:52:16 | 0:52:19 | |
and they're engaged, they're called hedonic systems. | 0:52:19 | 0:52:22 | |
It's much like what happens with drug addiction. | 0:52:24 | 0:52:27 | |
You don't need heroin, you don't need cocaine, | 0:52:27 | 0:52:29 | |
it's got no nutrient value, it's got no caloric value, | 0:52:29 | 0:52:32 | |
it doesn't do anything for you except make you feel good. | 0:52:32 | 0:52:35 | |
And it's exactly those hedonic systems in the brain that we think | 0:52:38 | 0:52:41 | |
are being impacted far more when you consume food | 0:52:41 | 0:52:45 | |
that's rich in fat and sugar, than consuming either sugar or fat alone. | 0:52:45 | 0:52:49 | |
When you think about it, we all know we need to eat to live. | 0:52:52 | 0:52:55 | |
But what Professor Kenny's discovered is that the combination | 0:52:59 | 0:53:02 | |
of fat and sugar supercharges the brain's reward system, | 0:53:02 | 0:53:06 | |
overpowering its ability to tell us to stop eating. | 0:53:06 | 0:53:10 | |
And it's a manufactured combination, | 0:53:13 | 0:53:16 | |
you can't find it anywhere else in nature. | 0:53:16 | 0:53:18 | |
But here's what's even more remarkable. | 0:53:25 | 0:53:27 | |
He's discovered that his rats didn't just like | 0:53:29 | 0:53:31 | |
a mixture of fat and sugar, | 0:53:31 | 0:53:33 | |
the ratio of fat to sugar was crucial to how much they liked it. | 0:53:33 | 0:53:38 | |
When I looked at the composition of cheesecake and I was surprised. | 0:53:40 | 0:53:43 | |
It had a highest percentage of fat of any food item | 0:53:43 | 0:53:47 | |
that we looked at that wasn't actually pure fat, | 0:53:47 | 0:53:49 | |
and it had remarkably high levels of sugar. So it was | 0:53:49 | 0:53:52 | |
-the combination... -What's the ratio of fat and sugar in cheesecake? | 0:53:52 | 0:53:55 | |
-It's pretty much 50/50. -Really? | 0:53:55 | 0:53:57 | |
It's about a half fat and the rest of it sugar | 0:53:57 | 0:53:59 | |
with various other things to keep the whole product together. | 0:53:59 | 0:54:02 | |
-OK. -So it's basically half fat and half sugar. | 0:54:02 | 0:54:05 | |
Chaps, can I offer you doughnuts? | 0:54:05 | 0:54:06 | |
OK, there you go, go for it. | 0:54:06 | 0:54:08 | |
-I like these ones. -Tuck in, there's no trick. | 0:54:08 | 0:54:11 | |
Now remember, the most popular doughnut was this one, | 0:54:13 | 0:54:16 | |
the glazed ring, | 0:54:16 | 0:54:18 | |
and there's something really special about this doughnut, | 0:54:18 | 0:54:21 | |
it's got an exactly 50/50 mixture of fat and sugar. | 0:54:21 | 0:54:25 | |
The pink one, that's got extra sugar on the top, | 0:54:25 | 0:54:28 | |
and this one is filled with cream. | 0:54:29 | 0:54:32 | |
So there's no question, | 0:54:33 | 0:54:34 | |
we absolutely love this combination of fat and sugar. | 0:54:34 | 0:54:38 | |
It's no surprise that people liked this doughnut. | 0:54:40 | 0:54:43 | |
It tends to be the bestseller on both sides of the Atlantic. | 0:54:43 | 0:54:46 | |
The fact that the world is getting fatter is a new phenomenon, | 0:54:52 | 0:54:55 | |
and what seems to be driving it, | 0:54:55 | 0:54:57 | |
at least according to Professor Kenny, is processed food, | 0:54:57 | 0:55:00 | |
because that's where you find this deadly combination | 0:55:00 | 0:55:03 | |
of fat and sugar that you don't find anywhere else in nature. | 0:55:03 | 0:55:07 | |
And what this does is it fundamentally interferes | 0:55:07 | 0:55:11 | |
with our mechanisms of self-regulation and reward. | 0:55:11 | 0:55:14 | |
It seems that it's fat and sugar together, | 0:55:22 | 0:55:25 | |
not fat or sugar alone, that's the real problem. | 0:55:25 | 0:55:28 | |
And Chris wanted to find out from Professor Jebb what we could do about it. | 0:55:30 | 0:55:35 | |
When people tell me they crave sugar, | 0:55:36 | 0:55:38 | |
I say, "What, sugar out of the sugar bowl? | 0:55:38 | 0:55:41 | |
"Oh, no, no, no." Or fat, pats of butter? Generally not. | 0:55:41 | 0:55:44 | |
What people really seem to desire, whether that's physiological | 0:55:44 | 0:55:48 | |
or whether it's a learnt behaviour is these fat/sugar combinations. | 0:55:48 | 0:55:52 | |
They are very energy dense, so they pack the calories in, | 0:55:52 | 0:55:56 | |
and they are unbelievably pleasurable and attractive. | 0:55:56 | 0:55:59 | |
Are these temptations for you as well? | 0:55:59 | 0:56:01 | |
Oh, I think they're temptations for most of us. | 0:56:01 | 0:56:03 | |
One of the things that I often say | 0:56:03 | 0:56:05 | |
is it's astonishing that any of us stay slim. | 0:56:05 | 0:56:09 | |
In a world like this where in Britain we are surrounded | 0:56:09 | 0:56:12 | |
by pretty delicious, relatively affordable, palatable foods, | 0:56:12 | 0:56:18 | |
actually you have to exert quite a level of dietary restraint | 0:56:18 | 0:56:22 | |
if you're not going to effectively just sleep-walk into obesity. | 0:56:22 | 0:56:26 | |
So I want your top tip, | 0:56:26 | 0:56:28 | |
a basic rule, like my go to thing when I'm feeling weak. | 0:56:28 | 0:56:32 | |
By making some pretty modest changes, but right across your diet. | 0:56:32 | 0:56:36 | |
Certainly cutting out some of those kind of discretionary | 0:56:36 | 0:56:40 | |
treat type foods which are no longer really treats, | 0:56:40 | 0:56:44 | |
-they've become everyday items. -Yes. | 0:56:44 | 0:56:46 | |
If you take those out you can cut calories | 0:56:46 | 0:56:48 | |
and you can cut lots of those other nutrients of concern. | 0:56:48 | 0:56:52 | |
So you end up with a healthier diet | 0:56:52 | 0:56:54 | |
and one on which you can also lose some weight. | 0:56:54 | 0:56:57 | |
And I think that really is the secret to developing | 0:56:57 | 0:56:59 | |
a much more holistic attitude to food, | 0:56:59 | 0:57:03 | |
which doesn't sort of believe that any one item is a saviour | 0:57:03 | 0:57:08 | |
or a sinner, it is about the overall balance of the diet. | 0:57:08 | 0:57:12 | |
We've all heard that before | 0:57:20 | 0:57:21 | |
but the difference is that we now know our enemy. | 0:57:21 | 0:57:25 | |
It's not fat. | 0:57:27 | 0:57:28 | |
And it's not sugar. | 0:57:30 | 0:57:32 | |
But the deadly, addictive, | 0:57:33 | 0:57:35 | |
delicious mixture of fat and sugar combined. | 0:57:35 | 0:57:39 | |
What's amazing to me about all this is that | 0:57:42 | 0:57:45 | |
I've been a doctor for ten years, | 0:57:45 | 0:57:47 | |
I've spent six years at medical school, | 0:57:47 | 0:57:48 | |
and I thought I knew a lot of this stuff and I just didn't, | 0:57:48 | 0:57:52 | |
like I was wrong about a lot of stuff. | 0:57:52 | 0:57:54 | |
So basically what I get out of this is | 0:57:54 | 0:57:56 | |
I have to avoid the processed food, the doughnuts, the ice cream, | 0:57:56 | 0:58:00 | |
the cheesecake, that sort of 50/50 fat/sugar mixture | 0:58:00 | 0:58:04 | |
I cannot stop eating, and it's... and that's the problem. | 0:58:04 | 0:58:07 | |
So I'm going to cut those out completely. | 0:58:07 | 0:58:09 | |
So that where I end up is going all faddish diets, | 0:58:09 | 0:58:12 | |
all faddish diets, are wrong and misguided, | 0:58:12 | 0:58:16 | |
-all of them. -Yeah. | 0:58:16 | 0:58:17 | |
And doing exercise is really important. | 0:58:17 | 0:58:19 | |
You need to keep the muscle because muscle is an endocrine organ | 0:58:19 | 0:58:22 | |
that affects your whole metabolism. | 0:58:22 | 0:58:25 | |
So, in the end, as doctors, we'd love to be able to give | 0:58:25 | 0:58:27 | |
one simple rule or give you a pill that would fix all this, | 0:58:27 | 0:58:30 | |
but in the end we can't. | 0:58:30 | 0:58:32 | |
-It's up to you. -It's up to YOU. | 0:58:32 | 0:58:34 | |
All right, it's up to... It's up to you too. | 0:58:34 | 0:58:37 |