Why Are We Getting So Fat?

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0:00:04 > 0:00:08Britain is in the grip of an obesity epidemic.

0:00:08 > 0:00:12We can't seem to stop eating and we are getting fatter.

0:00:13 > 0:00:15It's one of the greatest public health challenges

0:00:15 > 0:00:17of the 21st century

0:00:17 > 0:00:21and rarely out of the papers.

0:00:21 > 0:00:23"Aporkerlypse Now."

0:00:23 > 0:00:26"Obesity as big a threat to the UK as terrorism."

0:00:28 > 0:00:33Obesity is all over the news and it garners really shocking headlines.

0:00:33 > 0:00:38In recent years, attitudes are becoming more and more judgmental.

0:00:38 > 0:00:40There's lots of things that I can't stand

0:00:40 > 0:00:43but one of them in particular is fat children.

0:00:43 > 0:00:46Do you know who is responsible for you being fat? You. That's it.

0:00:46 > 0:00:48When I sit there and I look at somebody that's overweight,

0:00:48 > 0:00:50I find that really repulsive and disgusting.

0:00:50 > 0:00:53And the verdict seems to be that the obese people are to blame.

0:00:53 > 0:00:58They are slothful, they are lazy, they are bad.

0:00:58 > 0:01:01In my view, nothing could be further from the truth.

0:01:01 > 0:01:04My name is Giles Yeo. I'm a geneticist.

0:01:04 > 0:01:07I study genes that are linked to obesity.

0:01:07 > 0:01:11I spend most of my time pipetting liquids from one thing to another.

0:01:11 > 0:01:15But these test tubes can't tell the full story.

0:01:15 > 0:01:19What I want to do is to actually know the person behind these genes.

0:01:19 > 0:01:24I want to meet the people behind some of the more alarming headlines.

0:01:24 > 0:01:29A lot of fat people, we put on a good facade but inside we're crying.

0:01:29 > 0:01:33I want to hear from them why they think they can't stop eating.

0:01:33 > 0:01:36That was a general lunch for me.

0:01:36 > 0:01:38That was me at the age of 15 there,

0:01:38 > 0:01:40not long before I made the decision to lose weight.

0:01:40 > 0:01:44I want to dispel some of the myths about obesity...

0:01:44 > 0:01:47You're not lazy. It's not because you lack willpower.

0:01:47 > 0:01:50You guys are fighting your biology.

0:01:50 > 0:01:52..and see what solutions science can offer.

0:01:52 > 0:01:55So what we're hoping the faecal transplant will do is help people to

0:01:55 > 0:01:59feel more full and therefore will influence weight loss.

0:01:59 > 0:02:03Fast forward ten years, obesity won't be a problem.

0:02:03 > 0:02:05They'll have the injections. They'll be painless.

0:02:05 > 0:02:07No side effects

0:02:07 > 0:02:10and actually really inexpensive and freely available.

0:02:22 > 0:02:26What's it actually like to live with obesity?

0:02:26 > 0:02:29I'm bringing together a group of obese people to hear their views.

0:02:32 > 0:02:35With obesity, I think people do treat you differently.

0:02:35 > 0:02:38They ignore you. They don't see you as a real person.

0:02:38 > 0:02:41Some people have let doors just slam in my face,

0:02:41 > 0:02:44looked me up and down in disgust.

0:02:44 > 0:02:46You can see their mouths dropping open

0:02:46 > 0:02:50because they are just thinking, "Who is that?!"

0:02:50 > 0:02:55People certainly think that because you are fat you're not intelligent.

0:02:55 > 0:03:00It's a very frustrating thing when people judge you for how you look.

0:03:00 > 0:03:02I just think we need to get to a place

0:03:02 > 0:03:05where we're just kind to people.

0:03:05 > 0:03:08I'm taking a break from my laboratory work

0:03:08 > 0:03:11and getting ready for a road trip.

0:03:11 > 0:03:16Obesity is perceived as really quite a simple problem,

0:03:16 > 0:03:18like eat less, move more.

0:03:18 > 0:03:20And that is fine. Simple physics.

0:03:20 > 0:03:25The problem, however, is that WHY people eat more is quite complex.

0:03:26 > 0:03:29On this trip, I'm going to meet some of the people

0:03:29 > 0:03:32behind the newspaper headlines.

0:03:32 > 0:03:36I hope my knowledge of obesity genetics can help them and, in turn,

0:03:36 > 0:03:40I hope THEY can help me understand the human side to obesity.

0:03:40 > 0:03:43I think it would really give me some fresh perspective

0:03:43 > 0:03:47and fresh impetus into the type of work that I do.

0:03:55 > 0:03:58'As well as the film crew joining me on the road trip,

0:03:58 > 0:04:01'I'll be recording some video diaries.

0:04:01 > 0:04:04'I think my own lifestyle choices could also offer some

0:04:04 > 0:04:07'insights into our relationship with food.'

0:04:07 > 0:04:09This is largely a bag of vegetables.

0:04:09 > 0:04:13Oh, there are a couple of naughty pizzas back there...

0:04:15 > 0:04:18...which we shan't talk about.

0:04:21 > 0:04:25For the first stop on this trip, it's time for a few home truths.

0:04:26 > 0:04:31I'm going to find out what my body mass index or BMI is.

0:04:31 > 0:04:34This is one way to discover if you are a healthy weight,

0:04:34 > 0:04:35overweight, or obese.

0:04:35 > 0:04:39Actually, do you know what, all this is adding weight, adding BMI.

0:04:39 > 0:04:42I'm going to take my clothes off.

0:04:42 > 0:04:45Well, not ALL my clothes.

0:04:45 > 0:04:49'BMI is a calculation of body size based on your weight

0:04:49 > 0:04:50'in relation to your height.'

0:04:50 > 0:04:54- MACHINE:- Stand still and keep your head upright.

0:04:54 > 0:04:58People with a BMI over 25...

0:04:58 > 0:05:00Please collect your ticket.

0:05:00 > 0:05:03...are classified overweight.

0:05:03 > 0:05:05HE LAUGHS

0:05:05 > 0:05:09My BMI is 27.1.

0:05:09 > 0:05:11That means I'm overweight.

0:05:11 > 0:05:16The problem with BMI is it doesn't actually tell you how much fat

0:05:16 > 0:05:18and how much muscle you have,

0:05:18 > 0:05:23so maybe underneath this shirt is a rippling bod of a Greek God?

0:05:23 > 0:05:25Or I'm carrying too much fat.

0:05:25 > 0:05:29'For another 20p, I can find out.'

0:05:29 > 0:05:34Firmly grip the handles at the sides, as shown in the figure.

0:05:34 > 0:05:37'By measuring how easily an electrical current travels

0:05:37 > 0:05:39'through my body and comparing it to my sex...'

0:05:39 > 0:05:41I am a male

0:05:41 > 0:05:43'..and age...'

0:05:43 > 0:05:45A youthful 42.

0:05:45 > 0:05:48'..it calculates my percentage body fat.'

0:05:48 > 0:05:52For men, it's recommended that this figure should be under 25.

0:05:52 > 0:05:54Please collect your ticket.

0:05:54 > 0:05:57'And mine is...'

0:05:57 > 0:05:5928%. That's awful!

0:05:59 > 0:06:02That's more than a quarter of me that's fat!

0:06:02 > 0:06:04Oh, God!

0:06:04 > 0:06:06I didn't know... I really genuinely...

0:06:06 > 0:06:09Guys, I genuinely did not know it was that bad.

0:06:09 > 0:06:11'This fat percentage is not great.

0:06:11 > 0:06:13'But what surprised me most

0:06:13 > 0:06:16'is how unrealistic I have been about my weight.'

0:06:16 > 0:06:19I don't think I look tremendously overweight.

0:06:19 > 0:06:21I think I look like the vast majority of the people

0:06:21 > 0:06:23wandering around outside.

0:06:23 > 0:06:27Is it because our perception of what is overweight and what is not

0:06:27 > 0:06:31overweight completely changed over the past few years?

0:06:31 > 0:06:33Whether we THINK we look fat or not,

0:06:33 > 0:06:37the current statistics make for uncomfortable headlines.

0:06:40 > 0:06:45Today, over 60% of Britons are overweight.

0:06:45 > 0:06:49Of these, around 40% have a BMI of over 30,

0:06:49 > 0:06:52which means they are classified as obese.

0:06:52 > 0:06:56And being obese can lead to heart disease, stroke and cancer,

0:06:56 > 0:07:00and reduce life expectancy by ten years.

0:07:00 > 0:07:02Health-wise, it's just not good at all.

0:07:02 > 0:07:06I've got severe diverticular disease.

0:07:06 > 0:07:09My knees are giving me awful trouble because of my weight itself.

0:07:09 > 0:07:12I was classed as type 2 diabetic.

0:07:12 > 0:07:14I've had high blood pressure, high cholesterol.

0:07:14 > 0:07:18Getting to an age where it's going to take its toll.

0:07:23 > 0:07:27Today I'm heading west up the M4 towards Wales.

0:07:29 > 0:07:32I've scoured newspapers from the last few years

0:07:32 > 0:07:36to find stories featuring obesity, and track down some of the people

0:07:36 > 0:07:38who have generated shocking headlines.

0:07:40 > 0:07:43I think there is a lot more going on in the lives of these people

0:07:43 > 0:07:46that is not captured in the headlines.

0:07:47 > 0:07:50I'm here driving through the fog to meet Les Price.

0:07:50 > 0:07:55Les is clinically obese and, because of his size,

0:07:55 > 0:07:57he made the headlines a few years back.

0:08:00 > 0:08:03This is the story I'm interested in.

0:08:03 > 0:08:07"37st man was told to buy two seats on a jet

0:08:07 > 0:08:11"and got one in row 17 and one in row 19."

0:08:11 > 0:08:13I want to find out what that experience must have been like

0:08:13 > 0:08:17for Les and also what else he has to say about being the size he is.

0:08:19 > 0:08:22It makes you feel stupid because of all the rigmarole,

0:08:22 > 0:08:25cos everyone's like, "What are they talking to him for?

0:08:25 > 0:08:28"What's going on there?" It was turning heads.

0:08:28 > 0:08:31It was like my life was put out there for everyone to see,

0:08:31 > 0:08:33whether I want it or not.

0:08:33 > 0:08:37Les has struggled with his size all his life.

0:08:37 > 0:08:42As an obese child, you are bullied, you are picked on.

0:08:42 > 0:08:45Nobody wants to pick you to play any of their games.

0:08:45 > 0:08:49I would go to the shop. I'd buy myself a fun-sized bag of whatever.

0:08:49 > 0:08:54I'd go home and just lock myself in the bedroom and hide.

0:08:54 > 0:08:56I didn't have to see nobody else.

0:08:56 > 0:09:01I could cry if I wanted and just have a tear to myself.

0:09:03 > 0:09:07Using food as a comfort is not uncommon and, for Les,

0:09:07 > 0:09:10this habit escalated when life dealt him a harsh blow.

0:09:13 > 0:09:15My wife died.

0:09:15 > 0:09:19We hadn't been married a year and it knocked me.

0:09:19 > 0:09:22I just didn't want to do nothing. I couldn't be bothered to cook.

0:09:22 > 0:09:24My daughter then, she come home from school,

0:09:24 > 0:09:26"Oh, can we have a takeaway?"

0:09:26 > 0:09:27"Go on, we'll have a takeaway."

0:09:27 > 0:09:30It was, like, for months that's all we had, was takeaway,

0:09:30 > 0:09:33but then that took me back then to when I was younger

0:09:33 > 0:09:36and the taste of something was the comfort.

0:09:36 > 0:09:38You know, you can wrap yourself in that blanket

0:09:38 > 0:09:41because it doesn't matter what anyone done out there,

0:09:41 > 0:09:45you're in that little comfort zone because a lot of fat people,

0:09:45 > 0:09:48we put on a good facade but inside we're crying.

0:09:48 > 0:09:50- Hmm.- You know.

0:09:52 > 0:09:56For Les, the way obese people are portrayed in the media

0:09:56 > 0:09:58only makes things worse.

0:09:58 > 0:10:03Fat people in the media, it just goes fat, that's it.

0:10:03 > 0:10:06They've got no idea what has happened in my life.

0:10:06 > 0:10:10Do I need you to come along and put a stamp on it and say, "You're fat."

0:10:10 > 0:10:14I know I'm fat, you know. I try my best to lose it.

0:10:14 > 0:10:17But it is hard work with life all-round.

0:10:17 > 0:10:22I am not physically able to go and exercise at the moment.

0:10:22 > 0:10:25I've got shoulder problems. I got arthritis in two knees.

0:10:25 > 0:10:27I need the help around me

0:10:27 > 0:10:31to put everything together to get other things going.

0:10:31 > 0:10:34- It sounds very frustrating, Les. - Life is very frustrating.

0:10:34 > 0:10:37People just see the fat guy and just think,

0:10:37 > 0:10:40"You've got to stop doing this."

0:10:43 > 0:10:47I was genuinely moved by meeting Les today.

0:10:47 > 0:10:49Clearly a number of different events have happened

0:10:49 > 0:10:53throughout his life to lead him to being the size he is.

0:10:53 > 0:10:55You could say that he just needs to reduce his calories

0:10:55 > 0:10:59and he would lose the weight and that is true, but the problem is,

0:10:59 > 0:11:03once you get into a vicious cycle of not being able to move, of being

0:11:03 > 0:11:07immobile, of needing someone to help you to go and get some exercise,

0:11:07 > 0:11:11then it gets very, very complicated to try and lose the weight.

0:11:11 > 0:11:15For me, Les' story illustrates how obesity in the real world is

0:11:15 > 0:11:18rarely straightforward.

0:11:18 > 0:11:20I used to turn to food for comfort

0:11:20 > 0:11:23and every time I was depressed or something like that,

0:11:23 > 0:11:24it would be straight to food

0:11:24 > 0:11:26and I would try and make myself feel better,

0:11:26 > 0:11:29but it was no good cos it was just making me bigger than better.

0:11:29 > 0:11:32My mum killed herself and I managed to hold it together for a short

0:11:32 > 0:11:37amount of time and then it was inevitable that I comfort ate.

0:11:37 > 0:11:39I think what a lot of people who have never been overweight

0:11:39 > 0:11:43don't realise is that food can actually be a bit of an addiction.

0:11:43 > 0:11:45The problem with an addiction to food is that you can't just

0:11:45 > 0:11:48quit cold turkey like you can if you're smoking or

0:11:48 > 0:11:51if you're drinking cos you've still got to eat every day or you'll die.

0:11:59 > 0:12:02Given the complexity of this obesity epidemic,

0:12:02 > 0:12:04where DOES the fault lie?

0:12:08 > 0:12:10It has been a long day's filming so far.

0:12:10 > 0:12:13I am tired, I am hungry, and my day is not over,

0:12:13 > 0:12:15I have still got another four hours' drive

0:12:15 > 0:12:17before I can actually get home.

0:12:17 > 0:12:21I'm going to need to get some food as fuel to get me home.

0:12:21 > 0:12:25Ah-ha, here might be some options.

0:12:25 > 0:12:28There we go, here is Domino's, Papa John's pizza...

0:12:30 > 0:12:32I'd be kidding myself

0:12:32 > 0:12:36if I said I wasn't secretly enjoying the prospect of this takeaway binge.

0:12:42 > 0:12:44I am starving, it is time to eat.

0:12:45 > 0:12:47OK, what do we have here? We have got...

0:12:47 > 0:12:49I've got myself a fish burger.

0:12:50 > 0:12:52I've got myself a large fries.

0:12:55 > 0:12:57And I have got myself apple pie,

0:12:57 > 0:12:58lovely apple pie.

0:13:01 > 0:13:03Now I'm going to open some sweet-and-sour sauce

0:13:03 > 0:13:05to go with my chips.

0:13:05 > 0:13:09Because who doesn't like some highly refined carbohydrates

0:13:09 > 0:13:15and sugar, overly sweetened, to go with fried goods such as a chip?

0:13:17 > 0:13:19Fan...

0:13:19 > 0:13:21tastic.

0:13:21 > 0:13:24It's actually fantastic, I do like it.

0:13:24 > 0:13:28'To burn this lot off, I would have to walk for nearly four hours.

0:13:28 > 0:13:31'But with the long drive ahead, that is not going to happen.'

0:13:31 > 0:13:34I have fallen into the classic trap of needing food

0:13:34 > 0:13:36when you're in a rush and when you need something quick.

0:13:36 > 0:13:41And what do they tend to be? Highly processed, the fish is fried and...

0:13:42 > 0:13:46And what am I doing? I am doing this because this is what is available.

0:13:46 > 0:13:49This would not have happened before, I mean, 10,000 years ago

0:13:49 > 0:13:52on the Serengeti when you are trying to pull back an antelope.

0:13:52 > 0:13:56It would have cost you 2,000 calories to get the antelope.

0:13:56 > 0:14:00We like to think that we have full control over the decisions

0:14:00 > 0:14:01we take about our food.

0:14:02 > 0:14:06"I control what I eat, I am a human being, I have free will."

0:14:06 > 0:14:10The problem is, our urge to eat, particularly in such

0:14:10 > 0:14:17a high-energy-dense environment, is a product of thousands,

0:14:17 > 0:14:20hundreds of thousands of years of evolution.

0:14:23 > 0:14:24In the developed world,

0:14:24 > 0:14:28we have never had so much available to eat and so little to do.

0:14:30 > 0:14:34In the last 20 years, the number of takeaways has soared.

0:14:39 > 0:14:42And research has shown that living and working near

0:14:42 > 0:14:44a high density of takeaway outlets doubles your likelihood

0:14:44 > 0:14:46of being obese.

0:14:50 > 0:14:54So on this stretch of one high street in what may be

0:14:54 > 0:14:58a typical town in the UK, I have counted eight takeaways.

0:14:58 > 0:15:01And this is what we would call an obesogenic environment.

0:15:01 > 0:15:03And we are susceptible to it, there is a mismatch

0:15:03 > 0:15:09between a brain that thinks we are still supposed

0:15:09 > 0:15:13to be putting on energy because we might starve at any point

0:15:13 > 0:15:18and an environment which encourages our baser instincts

0:15:18 > 0:15:20in order to eat more.

0:15:22 > 0:15:26And some people seem to be affected by these instincts more than others.

0:15:31 > 0:15:33They find it particularly hard to resist

0:15:33 > 0:15:36the temptation of calorie-rich food.

0:15:36 > 0:15:39My favourite naughty snack that I find very hard to resist

0:15:39 > 0:15:40has got to be Mars ice creams.

0:15:40 > 0:15:42Cakes.

0:15:42 > 0:15:45Cakes and doughnuts and... custard slices.

0:15:45 > 0:15:47Sausage rolls, pies, pasties.

0:15:47 > 0:15:51If I am at a buffet, don't even think about getting any Doritos,

0:15:51 > 0:15:53because I will be there just shovelling them into my face.

0:15:53 > 0:15:55- LAUGHING:- I love them so much.

0:15:58 > 0:16:02I believe that genetics play an important part in the reasons

0:16:02 > 0:16:04why some people eat more than others.

0:16:04 > 0:16:05Some cake for you.

0:16:05 > 0:16:09- Oh, fantastic.- There you go. - Thank you so much.

0:16:09 > 0:16:11And I have spent my career investigating

0:16:11 > 0:16:13which genes are responsible.

0:16:15 > 0:16:17We know that there are over 100 genes

0:16:17 > 0:16:19that are linked to common obesity.

0:16:19 > 0:16:22Of these, the one with the largest effect is a gene called

0:16:22 > 0:16:25"fat mass and obesity-related transcript",

0:16:25 > 0:16:27or FTO.

0:16:27 > 0:16:28Now, all of us have FTO.

0:16:29 > 0:16:32Some of us, however, have inherited

0:16:32 > 0:16:34a slightly different version of FTO

0:16:34 > 0:16:36which increases our risk of becoming obese.

0:16:38 > 0:16:41'Half of the population have a version of FTO that contains

0:16:41 > 0:16:44'just one small change.'

0:16:44 > 0:16:47And what this means is that we are a kilo-and-a-half heavier

0:16:47 > 0:16:51and 25% more likely to become obese.

0:16:51 > 0:16:54'But roughly one in six of us are unlucky enough to have

0:16:54 > 0:16:58'two small changes, or a "double-risk variant" of FTO.

0:16:58 > 0:17:01'And they are more likely to want to eat more...'

0:17:01 > 0:17:02They are on average 3kg heavier,

0:17:02 > 0:17:08and critically, are 50% more likely to become obese.

0:17:08 > 0:17:11'I have been studying the FTO gene for over eight years.

0:17:12 > 0:17:15'And we now know that these genetic variations have been linked

0:17:15 > 0:17:19'to changes in the brain which make it less sensitive

0:17:19 > 0:17:23'to appetite hormones released from the gut and fat cells.

0:17:23 > 0:17:26'This in turn affects how hungry we feel.'

0:17:27 > 0:17:31I'm curious to see how this insight translates into the real world.

0:17:34 > 0:17:38I want to find out if knowing if you have any FTO risk variants

0:17:38 > 0:17:40can actually help with one of

0:17:40 > 0:17:43obesity's biggest challenges - dieting.

0:17:43 > 0:17:46Every time there has been a diet, I have tried it.

0:17:46 > 0:17:49We have had the smelly cabbage diet in my life.

0:17:49 > 0:17:51The Cambridge Diet...

0:17:51 > 0:17:54I did the coffee, chewing gum and fags diet

0:17:54 > 0:17:56in my late 20s.

0:17:56 > 0:17:57None of them worked.

0:17:57 > 0:18:02To be honest, any diet will work, providing you stick to it.

0:18:06 > 0:18:08Today, I have come to Colchester Town Hall

0:18:08 > 0:18:11in Essex to meet a group of dieters

0:18:11 > 0:18:13keen to find out more about their genetics.

0:18:14 > 0:18:17For all of our group they ask a really simple question,

0:18:17 > 0:18:19which is, "Why me?

0:18:19 > 0:18:21"Why is it that I struggle with my weight when I see people

0:18:21 > 0:18:23"all around me who clearly don't

0:18:23 > 0:18:25"seem to have the same problems that I do?

0:18:25 > 0:18:27"Is it that I am different in some way?"

0:18:27 > 0:18:30And obviously, your DNA is a very good place to start.

0:18:31 > 0:18:35I want to know if understanding their genetics can help motivate

0:18:35 > 0:18:38this diet group to lose more weight.

0:18:38 > 0:18:41You have to understand that the reason you guys are finding

0:18:41 > 0:18:44it difficult is not because you guys are bad.

0:18:44 > 0:18:47You are not bad, you are not lazy,

0:18:47 > 0:18:49it is not because you lack willpower.

0:18:49 > 0:18:52You guys are fighting your biology.

0:18:53 > 0:18:55'Today, some of the dieters are finding out

0:18:55 > 0:18:58'if they have any of the FTO risk variants.

0:18:58 > 0:19:01'First up is Tina.'

0:19:01 > 0:19:06Tina, you actually have two risk copies of FTO.

0:19:06 > 0:19:08Oh... Right, OK!

0:19:08 > 0:19:11Maybe that is why I have continually struggled with my weight

0:19:11 > 0:19:12over the years.

0:19:12 > 0:19:16- Susan, you also have two risk copies of it.- OK.

0:19:16 > 0:19:19'So Susan and Tina should be, on average,

0:19:19 > 0:19:23'about 3kg heavier than a person with no FTO risk variants.

0:19:23 > 0:19:26'But that doesn't mean they have to be.'

0:19:27 > 0:19:31I always consider your genes to be like a hand of poker.

0:19:31 > 0:19:33You get good hands and you get bad hands,

0:19:33 > 0:19:35and you can only blame your folks for it.

0:19:35 > 0:19:37But...

0:19:37 > 0:19:39you can win with a bad hand of poker

0:19:39 > 0:19:42and you can certainly lose with a good hand of poker.

0:19:42 > 0:19:45So it depends how you play the cards.

0:19:45 > 0:19:49It is more difficult, but you can win with a bad hand.

0:19:49 > 0:19:53'Winning with a bad hand is all about understanding how

0:19:53 > 0:19:56'obesity genes influence what we eat.

0:19:56 > 0:19:59'They actually change the way your brain interprets the signals

0:19:59 > 0:20:00'coming from your body.'

0:20:01 > 0:20:05These genes, what they do is they make your brain slightly less

0:20:05 > 0:20:08sensitive to the hormones.

0:20:08 > 0:20:11So your brain thinks that A -

0:20:11 > 0:20:14you have slightly less fat than you actually have,

0:20:14 > 0:20:16and B - you ate slightly less than you actually thought

0:20:16 > 0:20:19you did the last time round. Now, you don't

0:20:19 > 0:20:22eat twice as much as the person next to you, that is not what happens.

0:20:22 > 0:20:28You are eating 5% more, but 5% more every day of your life

0:20:28 > 0:20:30adds up to a huge lot of difference

0:20:30 > 0:20:32when you actually put it all together.

0:20:36 > 0:20:39It is lunchtime, and a perfect opportunity to find out

0:20:39 > 0:20:43if knowing they have any FTO risk variants influences

0:20:43 > 0:20:46how much these dieters eat and what food choices they make.

0:20:48 > 0:20:50Hi.

0:20:50 > 0:20:54I have asked obesity expert Dr Tony Goldstone to help me

0:20:54 > 0:20:58set up a rather unusual food demo to find out.

0:20:59 > 0:21:01We believe that if you have a double-risk variant

0:21:01 > 0:21:04it alters your brain structure and function.

0:21:04 > 0:21:06And we know from our brain imaging in some other

0:21:06 > 0:21:10genetic studies, that it may influence how the reward pathways

0:21:10 > 0:21:12in the brain work, leading to people craving

0:21:12 > 0:21:15and liking the high-energy foods much more.

0:21:16 > 0:21:21Tony has asked our dieters to give each of the foods a taste score.

0:21:21 > 0:21:23So what we're expecting is that those that have

0:21:23 > 0:21:27the double-risk FTO variant will be much more likely to like the foods

0:21:27 > 0:21:30high in fat and sugar, want to eat them and actually choose

0:21:30 > 0:21:34to eat them when given an option of a different buffet.

0:21:34 > 0:21:35That's the one.

0:21:35 > 0:21:39What the dieters don't know is that Tony is also secretly taking note

0:21:39 > 0:21:42of how much high-calorie creamy chicken soup

0:21:42 > 0:21:43and ice cream they consume.

0:21:43 > 0:21:46They are dieting, so they're very worried about gaining weight

0:21:46 > 0:21:48and wanting to lose weight, so it'll be interesting to see

0:21:48 > 0:21:52whether actually that alters the findings from what we expect.

0:21:53 > 0:21:55After lunch, Tony comes clean to the group

0:21:55 > 0:21:58and reveals some unexpected results.

0:22:03 > 0:22:05So we have never done this experiment before with people

0:22:05 > 0:22:08who know their genetics or who are dieting.

0:22:08 > 0:22:10And although the numbers are small,

0:22:10 > 0:22:12we have found some really interesting things.

0:22:12 > 0:22:16We have found that those that have the double variant were

0:22:16 > 0:22:21either much more likely to not have anything to eat

0:22:21 > 0:22:23or were more likely to choose the low-calorie options.

0:22:23 > 0:22:27And that suggests that if you know your genetic variant,

0:22:27 > 0:22:32you are much more likely to maybe alter your behaviour to avoid

0:22:32 > 0:22:34the high-calorie foods.

0:22:35 > 0:22:38These surprising results offer unexpected hope for the dieters.

0:22:38 > 0:22:41We expected the opposite,

0:22:41 > 0:22:43we expected those with the double variant to actually eat

0:22:43 > 0:22:45and choose more of those high-energy foods,

0:22:45 > 0:22:48but the crucial difference here in this study is that

0:22:48 > 0:22:51they actually knew what their genetics were.

0:22:51 > 0:22:54It suggests knowing you have got a bad hand of obesity genes

0:22:54 > 0:22:56CAN help dieters.

0:22:57 > 0:22:59It is in my head now,

0:22:59 > 0:23:02I have got to use that extra information that I have got.

0:23:02 > 0:23:05Yes, I will use it and see if I can incorporate it

0:23:05 > 0:23:07in any weight-loss plan.

0:23:07 > 0:23:09It really helps to understand, perhaps, how for me,

0:23:09 > 0:23:13as an individual, my biology is driving my weight,

0:23:13 > 0:23:16and more importantly, what I can do about it.

0:23:17 > 0:23:20Our experiment looked at just one meal.

0:23:20 > 0:23:22But I'm excited by the idea that simply knowing you have

0:23:22 > 0:23:27obesity genes can influence your relationship with food.

0:23:27 > 0:23:30With further research, this could become a powerful tool

0:23:30 > 0:23:32when it comes to losing weight.

0:23:36 > 0:23:38Yet, oddly,

0:23:38 > 0:23:41when it comes to finding out my own FTO status, I am undecided.

0:23:42 > 0:23:46In spite of all of the resources at my disposal -

0:23:46 > 0:23:50and these are the exact machines we use to make

0:23:50 > 0:23:53genetic measurements - I don't know my FTO risk status.

0:23:53 > 0:23:57Do I have one or two copies of the FTO risk variant?

0:23:58 > 0:24:01Maybe it's because I am not obese - yet.

0:24:01 > 0:24:03And I don't feel I need to know.

0:24:03 > 0:24:05If, however, I have been struggling

0:24:05 > 0:24:06with my weight all of my life,

0:24:06 > 0:24:08maybe that would be different.

0:24:14 > 0:24:17I believe the food-rich world we live in today puts

0:24:17 > 0:24:20the small group of the population carrying the double-risk variant

0:24:20 > 0:24:22of FTO at a disadvantage.

0:24:24 > 0:24:28But it is not all bad news. We now know of one hidden benefit.

0:24:30 > 0:24:34On the next leg of my journey, I'm going to meet someone whose story

0:24:34 > 0:24:37is a great example of how exercise can exploit a bad genetic hand.

0:24:42 > 0:24:45I am on my way to Merthyr Tydfil in Wales,

0:24:45 > 0:24:48where, in the past, it has had the dubious honour of being named

0:24:48 > 0:24:49the fattest town in Wales.

0:24:53 > 0:24:5825-year-old Nathan Hewitt once hit the headlines as one of

0:24:58 > 0:25:00Britain's most obese schoolchildren.

0:25:00 > 0:25:02He has taken me to this cafe to show me

0:25:02 > 0:25:05what he used to eat on a regular basis.

0:25:06 > 0:25:09- Here you go.- Oh, fantastic, thank you so much.- Enjoy.

0:25:09 > 0:25:11- Thank you so much.- All right.

0:25:11 > 0:25:13Gosh, the... The portions are very big here.

0:25:13 > 0:25:17Yeah. This is something I would eat on a regular basis, like, every week.

0:25:17 > 0:25:19- Really?- Yeah. Probably every weekend.

0:25:21 > 0:25:25That was me at the age of 15 there. At my heaviest.

0:25:25 > 0:25:27And how heavy?

0:25:27 > 0:25:3023st. Not long before I made the decision to lose weight.

0:25:30 > 0:25:34When you look at these pictures now, how does it make you feel?

0:25:34 > 0:25:37Looking at them now, I don't identify as this person any more.

0:25:37 > 0:25:41This is someone completely different to the person I am today.

0:25:41 > 0:25:43But at the same time, it is a sense of achievement.

0:25:43 > 0:25:47I am living proof that, on some level, we can change.

0:25:47 > 0:25:50'What has really impressed me about Nathan's transformation

0:25:50 > 0:25:54'is that he was dealt a bad hand when it comes to his obesity genes.

0:25:55 > 0:25:58'I have tested his genetics and discovered he has two copies

0:25:58 > 0:26:00'of the FTO risk variant,

0:26:00 > 0:26:03'making him 50% more likely to be obese.'

0:26:04 > 0:26:06Quite, you know, strange

0:26:06 > 0:26:11to be carrying a genetic that does predispose me for obesity,

0:26:11 > 0:26:16yet still living my life today as someone I consider slim and healthy.

0:26:17 > 0:26:21The slim and healthy Nathan of today is the result of a hard-fought battle

0:26:21 > 0:26:24to change unhealthy childhood habits.

0:26:26 > 0:26:29I spent a lot of my young teenage years hanging around

0:26:29 > 0:26:33in this area. I would eat junk food from the local corner shop there.

0:26:33 > 0:26:37Crisps, chocolate, full-sugar Coke.

0:26:37 > 0:26:40Constantly just snacking and...

0:26:40 > 0:26:41What made you change?

0:26:41 > 0:26:45Well, from the age of 11 to the age of 14,

0:26:45 > 0:26:47every summer we would take a trip to Alton Towers.

0:26:47 > 0:26:50I waited in queue for about an hour and a half,

0:26:50 > 0:26:54looking forward to getting on this ride, and I couldn't fit on there.

0:26:54 > 0:26:58The clamp wouldn't close down, and I remember being told,

0:26:58 > 0:27:02"Sorry, mate, but you're going to have to leave the ride."

0:27:02 > 0:27:06And that really was... That was hard for me.

0:27:06 > 0:27:08This experience was the motivation

0:27:08 > 0:27:12Nathan needed to change his diet and cut out the fatty foods.

0:27:12 > 0:27:13And I lost the weight,

0:27:13 > 0:27:17and the following year I went back on that ride, and I fitted on there.

0:27:19 > 0:27:22But for me, what is really interesting is how big a role

0:27:22 > 0:27:26exercise may have played in Nathan's transformation.

0:27:26 > 0:27:27I opted for weights.

0:27:27 > 0:27:30So altogether, when I finally reached my ideal size,

0:27:30 > 0:27:34I had lost just over 11st in weight,

0:27:34 > 0:27:39- I went from just under 23st down to 11st.- 11st?- Yeah.

0:27:40 > 0:27:42Nathan's combination of exercise

0:27:42 > 0:27:46and FTO double-risk variant could be the key to his success.

0:27:46 > 0:27:50Although scientists don't know why, they have discovered that

0:27:50 > 0:27:53for those with a double FTO risk variant,

0:27:53 > 0:27:56exercise can mitigate against the risk of obesity by 30%

0:27:56 > 0:27:59compared to those with no risk variants.

0:28:01 > 0:28:04It is an extraordinary finding.

0:28:04 > 0:28:06Having the double FTO risk variant will increase

0:28:06 > 0:28:09your likelihood for being obese, but the good news is

0:28:09 > 0:28:13it also enables you to lose more weight if you exercise.

0:28:15 > 0:28:19Well, I have just come back from a run on a lovely winter's morning.

0:28:19 > 0:28:21I have been travelling so much lately I haven't got as much

0:28:21 > 0:28:24cycling in, so I have been trying to supplement my exercise.

0:28:24 > 0:28:27You see? I'm practising what I preach.

0:28:27 > 0:28:30Trying to play my hand in life as best as I can.

0:28:38 > 0:28:41Today, I am on my way to Southampton.

0:28:43 > 0:28:45I have heard about new genetic discoveries that could have

0:28:45 > 0:28:49serious implications for obesity in generations to come.

0:28:57 > 0:29:00These babies are just a few hours old.

0:29:00 > 0:29:02But it is possible that some of them

0:29:02 > 0:29:04are already set on a path to obesity.

0:29:08 > 0:29:10According to Professor Keith Godfrey,

0:29:10 > 0:29:13it is not only down to the genetics they have inherited,

0:29:13 > 0:29:17but also how genes are switched on or off during life in the womb.

0:29:20 > 0:29:24We have always known that a mother's nutrition and lifestyle

0:29:24 > 0:29:29is really important for the growth and development of her baby.

0:29:29 > 0:29:33What we know now is it has a long-term effect on the health

0:29:33 > 0:29:35of the baby, and part of that

0:29:35 > 0:29:39includes a big predisposition to obesity.

0:29:41 > 0:29:45Keith's research suggests foods that releases sugars quickly into

0:29:45 > 0:29:47a pregnant mother's circulation can have a lasting impact

0:29:47 > 0:29:49on their baby's weight.

0:29:50 > 0:29:54These high sugar levels flow across the placenta and affect

0:29:54 > 0:29:57the way in which the unborn baby's genes are turned on or off.

0:29:59 > 0:30:01There are switches, chemical switches,

0:30:01 > 0:30:05on the DNA which are influenced by the mother's sugar levels

0:30:05 > 0:30:08and her diet, which tell one cell to be a muscle cell

0:30:08 > 0:30:11and another cell to be a fat cell.

0:30:11 > 0:30:14And when there are excessive amounts of sugar

0:30:14 > 0:30:19coming across the placenta, then there is an excess of fat cells.

0:30:19 > 0:30:22And that excess fat cell complement, it's with you forever.

0:30:24 > 0:30:28According to Keith, these effects are associated with more than

0:30:28 > 0:30:30a fivefold increase in the risk of childhood obesity.

0:30:33 > 0:30:36While the months in the womb are critical for

0:30:36 > 0:30:38the next generation's future risk of obesity,

0:30:38 > 0:30:42scientist believe that there may be another window of opportunity

0:30:42 > 0:30:44to stop the obesity epidemic,

0:30:44 > 0:30:47long before the babies are even conceived...

0:30:51 > 0:30:52..the teenage years.

0:30:52 > 0:30:57This is University Hospital Southampton's LifeLab.

0:30:57 > 0:31:02Today, a group of schoolchildren are analysing DNA samples that

0:31:02 > 0:31:04illustrate how diet and lifestyle can

0:31:04 > 0:31:08switch on or off a range of different genes linked to obesity.

0:31:13 > 0:31:18The DNA the children are analysing belongs to parents

0:31:18 > 0:31:20with healthy diets and parents with unhealthy diets,

0:31:20 > 0:31:23and their respective babies.

0:31:23 > 0:31:28LifeLab programme manager Kathryn Woods-Townsend explains the results.

0:31:29 > 0:31:33OK, sample one is the DNA from a mother who had a healthy diet

0:31:33 > 0:31:37while she was pregnant, and the DNA from her offspring,

0:31:37 > 0:31:40and you can see it is identical.

0:31:40 > 0:31:42And then we have the DNA from a mother who didn't have such

0:31:42 > 0:31:48a healthy diet, and the DNA from her offspring, and what do you notice?

0:31:48 > 0:31:50The patterns are different.

0:31:50 > 0:31:53The changed pattern means that the baby's gene has been altered

0:31:53 > 0:31:57by the mother's poor diet, putting them at greater risk of obesity.

0:31:59 > 0:32:01And it is not just expectant mums that can

0:32:01 > 0:32:04influence their unborn child's risk.

0:32:04 > 0:32:07It is really important for us to keep the boys engaged

0:32:07 > 0:32:10and show that actually, they are just as crucial in this process.

0:32:10 > 0:32:14So here we have DNA from a father who had a healthy diet,

0:32:14 > 0:32:16and his offspring's DNA.

0:32:16 > 0:32:19DNA from a father who had an unhealthy diet,

0:32:19 > 0:32:20and his offspring's DNA.

0:32:20 > 0:32:24And again, you can see that the patterns are different.

0:32:24 > 0:32:27So at a really simple level the message we are trying to get across

0:32:27 > 0:32:32is that actually, what you do during your life can change your DNA.

0:32:32 > 0:32:36But not only for yourselves, but also for your future families.

0:32:36 > 0:32:37Not trying to scare you guys.

0:32:37 > 0:32:39LAUGHTER

0:32:39 > 0:32:42It is kind of scary, but then you can also use it as a motivation

0:32:42 > 0:32:46to maybe eat healthy or be a bit more active in your lifetime.

0:32:49 > 0:32:51What an absolutely inspiring day.

0:32:51 > 0:32:54It was fabulous to see these kids engage with science,

0:32:54 > 0:32:57engage with their health, and at this early stage in life,

0:32:57 > 0:33:00when they can do something about it before they become unhealthy,

0:33:00 > 0:33:05before they become obese. As a scientist, I love this place.

0:33:05 > 0:33:07As a parent, I love this place.

0:33:13 > 0:33:16Educating the next generation is undoubtedly a positive step

0:33:16 > 0:33:18towards stopping obesity.

0:33:19 > 0:33:21But what are the options now?

0:33:32 > 0:33:34The only treatment proven to be effective for

0:33:34 > 0:33:37sustained weight loss is bariatric surgery.

0:33:37 > 0:33:40This is when the stomach is reduced in size,

0:33:40 > 0:33:43and in some cases, the intestine is re-routed as well.

0:33:45 > 0:33:47I am here to meet Philip.

0:33:47 > 0:33:49He had bariatric surgery last year,

0:33:49 > 0:33:53and I want to find out what difference it has made to his life.

0:33:55 > 0:33:58Coach driver Philip Perrot is keen to show me

0:33:58 > 0:34:01what he used to be able to eat before his operation.

0:34:04 > 0:34:09- This is what I used to eat. - Oh, my goodness.

0:34:09 > 0:34:12As you can see, you have got the steak and kidney pie,

0:34:12 > 0:34:14double portion.

0:34:14 > 0:34:16Double chips - lovely.

0:34:16 > 0:34:21And then munch my way through a box full of cream cakes.

0:34:21 > 0:34:23Generally 10 to 12 a day.

0:34:23 > 0:34:26That was a general lunch for me.

0:34:26 > 0:34:28Oh, my goodness.

0:34:28 > 0:34:31But now, if I am lucky, you can take all that away,

0:34:31 > 0:34:35and at a push, I might be able to eat all that.

0:34:35 > 0:34:40I think I would probably only manage half of the portion

0:34:40 > 0:34:43here of the steak and kidney pie, a third of the chips,

0:34:43 > 0:34:46and I would struggle to get through one cream bun.

0:34:47 > 0:34:50- But which one would you like? - The one with the jam.

0:34:53 > 0:34:56Philip had a gastric bypass operation.

0:34:56 > 0:34:58Typically these procedures reduce the stomach size

0:34:58 > 0:35:03from a capacity of 900ml to just 30

0:35:03 > 0:35:07and bypass more than a metre-long section of small intestine.

0:35:08 > 0:35:13This major surgery had a dramatic impact on Philip's appearance.

0:35:13 > 0:35:18This one is from 1999. When I was with my eldest son.

0:35:18 > 0:35:19- Svelte(!)- Gosh.

0:35:20 > 0:35:27And the second one is approximately two years later, about 2001, 2002.

0:35:27 > 0:35:29That is not you!

0:35:29 > 0:35:31That is, I'm afraid. That is me.

0:35:31 > 0:35:33How heavy were you?

0:35:33 > 0:35:37I would reckon I weighed about 25st at my heaviest,

0:35:37 > 0:35:42but now I am roughly 15st. That is a 10st loss.

0:35:42 > 0:35:46How has your life changed, then, after surgery?

0:35:46 > 0:35:48I am fitter than I ever have been.

0:35:48 > 0:35:52I don't snore so much - that was a big bonus.

0:35:52 > 0:35:56I'm actually still classed as a type 2 diabetic,

0:35:56 > 0:36:01although instead of having the 15 or 16 tablets that I used to

0:36:01 > 0:36:05take per day, I am not actually taking any medication now, at all.

0:36:07 > 0:36:10Surprisingly, Philip's dramatic health benefits and weight loss

0:36:10 > 0:36:14are not just thought to be the result of his reduced stomach.

0:36:16 > 0:36:20Scientists now know that surgery also alters the release

0:36:20 > 0:36:24of hormones, which in turn has a powerful influence on appetite.

0:36:25 > 0:36:28You know, I am genuinely shocked by the amount of food that

0:36:28 > 0:36:31Philip used to be able to eat in one sitting.

0:36:31 > 0:36:34And to hear about his staggering change

0:36:34 > 0:36:36in appetite before and after the surgery.

0:36:36 > 0:36:40'But bariatric surgery is expensive and not without risks.'

0:36:41 > 0:36:44The challenge is for scientists to try and control

0:36:44 > 0:36:46the levels of these hunger hormones, but without the surgery.

0:36:52 > 0:36:53Believe it or not,

0:36:53 > 0:36:57scientists are already on the brink of doing just that.

0:36:57 > 0:37:00It is a treatment that has been dubbed in the press

0:37:00 > 0:37:05as a "miracle jab" that could help up to 15 million people.

0:37:05 > 0:37:07If the scientists offered me an injection and said,

0:37:07 > 0:37:10"We guarantee this will make you thin", obviously I would take it.

0:37:10 > 0:37:12Oh, my gosh. Tell me more!

0:37:13 > 0:37:15SHE GASPS

0:37:15 > 0:37:19Please! I would love, love, love the injections.

0:37:22 > 0:37:25I have come to Hammersmith Hospital in southwest London.

0:37:27 > 0:37:29Here, Professor Steve Bloom and his team

0:37:29 > 0:37:32have created a cocktail of hunger hormones

0:37:32 > 0:37:34that mimics the physiological after-effects

0:37:34 > 0:37:36of gastric bypass surgery.

0:37:36 > 0:37:38Surgery is potentially dangerous.

0:37:38 > 0:37:41Maybe a half percent of people undergoing it

0:37:41 > 0:37:43will die from the procedure.

0:37:43 > 0:37:46A lot of complications, it is expensive,

0:37:46 > 0:37:50most of us don't want surgery, so it would be very nice to have

0:37:50 > 0:37:53some sort of injection which will do the same thing.

0:37:53 > 0:37:57'Professor Tricia Tan is overseeing the trial.'

0:37:57 > 0:37:59So, today we have two volunteers who have come in,

0:37:59 > 0:38:04and they will receive a triple gut hormone infusion.

0:38:04 > 0:38:09And what we will be looking at is how these hormones affect

0:38:09 > 0:38:14their appetite and food intake, and compare this with their

0:38:14 > 0:38:16previous visits, where they did not

0:38:16 > 0:38:20receive any hormones but just a placebo.

0:38:20 > 0:38:24These volunteers are part of a larger study.

0:38:24 > 0:38:25This is Giles.

0:38:25 > 0:38:27Nice to meet you, thank you for...

0:38:27 > 0:38:29So Fred is one of our study volunteers.

0:38:29 > 0:38:32- I snack a lot. - You snack, you are a grazer?

0:38:33 > 0:38:35Just going to pop that here.

0:38:35 > 0:38:39'The device will pump a steady stream of hormones into Fred's body,

0:38:39 > 0:38:42'which Tricia hopes will influence his appetite.'

0:38:42 > 0:38:44- OK, see you later. - Thanks a lot, Fred.- OK.

0:38:45 > 0:38:48'The hormones are given four hours to

0:38:48 > 0:38:50'take effect before the volunteers are offered lunch.'

0:38:52 > 0:38:54There you go, we can now prepare the food.

0:38:54 > 0:38:57- Essentially, we just use ready meals.- OK.

0:38:57 > 0:39:02- Is this one person's portion? - Yes.- Why are there three?

0:39:02 > 0:39:06We have to present them with food in excess.

0:39:06 > 0:39:09More food than they can actually eat.

0:39:10 > 0:39:14'The amount of food left over will allow Tricia to establish

0:39:14 > 0:39:18'how effective the hormone injection has been on their appetites.'

0:39:18 > 0:39:21Chicken tikka masala, special du jour.

0:39:23 > 0:39:27OK, Fred, here is the lunch, please eat until you

0:39:27 > 0:39:29are comfortably full and then buzz on the buzzer

0:39:29 > 0:39:31- when you are done, OK?- OK.

0:39:34 > 0:39:37Hi, Paul, here is your lunch.

0:39:42 > 0:39:46Paul and Fred press their buzzers when they are comfortably full.

0:39:46 > 0:39:48Thank you.

0:39:48 > 0:39:50- Thank you very much.- Thank you.

0:39:52 > 0:39:55Well, it looks like there is quite a bit of it there.

0:39:55 > 0:39:57I guess we won't know until we do the final weighing, but...

0:39:57 > 0:39:59(maybe it's worked.)

0:40:01 > 0:40:03OK. This is...

0:40:03 > 0:40:05Tricia compares the amount that

0:40:05 > 0:40:07Paul and Fred have eaten today with the last time

0:40:07 > 0:40:11they came into the hospital, when they were given a placebo injection.

0:40:13 > 0:40:17- For Paul, he has eaten 240 calories less.- 240 calories less?

0:40:17 > 0:40:18That's right.

0:40:18 > 0:40:21- And it's a 22% reduction.- Oh, OK.

0:40:21 > 0:40:26And Fred, again, 203 calories less than his first visit.

0:40:26 > 0:40:30- That is around 17% reduction. - Oh, gosh!

0:40:30 > 0:40:33Over a lifetime, say over even a few months,

0:40:33 > 0:40:35the amount of weight you would lose would be incredible.

0:40:35 > 0:40:36That's right.

0:40:38 > 0:40:41'It's extraordinary to think that the hormone injection has tricked

0:40:41 > 0:40:45'Paul and Fred's brains into thinking their stomachs are full.'

0:40:45 > 0:40:48How full are you feeling now?

0:40:48 > 0:40:51- Pretty full.- Yeah? - I feel comfortably full.

0:40:51 > 0:40:53Not hungry at all.

0:40:53 > 0:40:54- Fantastic.- You're welcome.

0:40:54 > 0:40:58'This change in appetite is typical of other volunteers in the trial.'

0:40:59 > 0:41:04With the injections of the hormones, the patients are eating

0:41:04 > 0:41:09up to 30% less than when they are not given the hormones.

0:41:09 > 0:41:12To be a really effective treatment for obesity,

0:41:12 > 0:41:16the goal is to create a hormone injection that doesn't just

0:41:16 > 0:41:20reduce the appetite one meal at a time, but lasts for a whole week.

0:41:21 > 0:41:25Fast forward ten years, obesity won't be a problem,

0:41:25 > 0:41:28They'll have the injections, they will be painless,

0:41:28 > 0:41:32no side-effects, and actually really inexpensive and freely available.

0:41:32 > 0:41:36So I think this is going to make an enormous difference.

0:41:36 > 0:41:40But for some, this miracle injection might not be the full answer.

0:41:40 > 0:41:44The problem is, I don't always eat when I am hungry.

0:41:44 > 0:41:45A lot of times I will eat

0:41:45 > 0:41:49because I am sad or bored or really happy with myself.

0:41:49 > 0:41:52So I am not sure that an appetite suppressant would

0:41:52 > 0:41:54really work for me anyway.

0:42:00 > 0:42:03For this leg of my road trip, I am in America.

0:42:05 > 0:42:08There has been a story in the press over here that is

0:42:08 > 0:42:11so extraordinary I have travelled over 3,000 miles

0:42:11 > 0:42:13to Providence, Rhode Island to find out more.

0:42:15 > 0:42:18Because I am making a film about obesity, I think it is

0:42:18 > 0:42:22inevitable that I was going to end up back here, in the United States.

0:42:22 > 0:42:25The ground zero, almost, of the problem.

0:42:27 > 0:42:30But the story I am investigating is not your classic tale

0:42:30 > 0:42:33of becoming obese through eating too much.

0:42:33 > 0:42:35It is an intriguing mystery that takes me

0:42:35 > 0:42:37right outside my field of expertise.

0:42:39 > 0:42:41I am entering the hidden world of gut bacteria.

0:42:47 > 0:42:52It is estimated that over 100 trillion bugs live inside our guts.

0:42:52 > 0:42:54There are over 1,000 different species,

0:42:54 > 0:42:57and only recently scientists have begun to understand

0:42:57 > 0:43:01the complex relationship these bugs have with our health.

0:43:01 > 0:43:06In the last few years, the spotlight has turned to obesity.

0:43:06 > 0:43:09And the press has had a field day with the idea that the

0:43:09 > 0:43:12bacteria living in our guts could affect our waistline.

0:43:14 > 0:43:18If the story is true, it could hold some potentially novel

0:43:18 > 0:43:22and really quite interesting clues as to one of the causes of obesity.

0:43:28 > 0:43:31The person I have come all this way to meet

0:43:31 > 0:43:33put on over 4st in two years.

0:43:33 > 0:43:36Now, there is nothing especially remarkable about that,

0:43:36 > 0:43:38but what IS unusual is the way

0:43:38 > 0:43:40she is thought to have gained the weight.

0:43:40 > 0:43:41HE RINGS DOORBELL

0:43:42 > 0:43:45- Hi!- Hi, how are you? - You must be Teresa.

0:43:45 > 0:43:46Yes, Teresa, nice to meet you.

0:43:46 > 0:43:50- Hello, I'm Giles, nice to meet you. It's cold.- Yes, very.

0:43:51 > 0:43:53Teresa wants to show me

0:43:53 > 0:43:57how much her body has changed in the last few years.

0:43:57 > 0:44:01- This here is me in 2006.- Oh, wow.

0:44:01 > 0:44:05- How heavy were you here? - I was 123lb.

0:44:05 > 0:44:07- I look great, huh? - You look great now.

0:44:07 > 0:44:11- And this one was me in 2012.- Wow.

0:44:13 > 0:44:152013 is when I was at my highest,

0:44:15 > 0:44:19and you won't find a picture of me at that point!

0:44:20 > 0:44:23Teresa's weight gain started shortly after

0:44:23 > 0:44:24she was cured of a painful

0:44:24 > 0:44:27and debilitating infection in her gut,

0:44:27 > 0:44:29caused by the bacteria Clostridium difficile,

0:44:29 > 0:44:32or C.diff for short.

0:44:32 > 0:44:35It caused a lot of pain, so I was in pain a lot of the time,

0:44:35 > 0:44:37almost like keeled-over pain.

0:44:37 > 0:44:40And I was physically exhausted from it.

0:44:40 > 0:44:43It was a very scary thing, very real, yeah.

0:44:45 > 0:44:49Her cure was an unpalatable-sounding treatment called

0:44:49 > 0:44:51faecal microbiota transplant.

0:44:51 > 0:44:53It involves transplanting faeces from

0:44:53 > 0:44:55a healthy donor into the unwell patient.

0:44:58 > 0:45:00Eugh!

0:45:00 > 0:45:03Probably what most people think when they hear it,

0:45:03 > 0:45:05it sounds a little gross.

0:45:05 > 0:45:09But it is exactly that, the idea is, with C.diff,

0:45:09 > 0:45:14it's a bad bacteria, so inside of my intestines, the C.diff,

0:45:14 > 0:45:16the bad bacteria, just overpopulated.

0:45:16 > 0:45:20So, in order to get rid of it, the idea is I would take

0:45:20 > 0:45:25a donor's faeces, which, at the time, I used my daughter's.

0:45:25 > 0:45:28And the good bacteria from my daughter's faeces would

0:45:28 > 0:45:31overpopulate the bad and clear it up.

0:45:31 > 0:45:34And literally, like this,

0:45:34 > 0:45:38the next day, it was amazing. It was unbelievable.

0:45:38 > 0:45:43I got instant, instant, instant relief from my symptoms.

0:45:43 > 0:45:46While she was cured of her C.diff, Teresa's recovery came

0:45:46 > 0:45:49with an unwanted side-effect.

0:45:49 > 0:45:54Initially, everything felt great, for about six months,

0:45:54 > 0:45:57and then I noticed my clothes weren't fitting me the same.

0:45:57 > 0:46:01So I had had this slow, but gradual weight increase.

0:46:01 > 0:46:03I literally went from a size two, size four, size six,

0:46:03 > 0:46:06size eight, size ten... You know what I mean? 12, 14...

0:46:06 > 0:46:08And before I knew it,

0:46:08 > 0:46:12I had about a 60lb weight increase within a matter

0:46:12 > 0:46:13of two to three years.

0:46:15 > 0:46:17Teresa is convinced that her weight gain was

0:46:17 > 0:46:21caused by the sample of faeces her daughter donated.

0:46:21 > 0:46:24I have never had a problem with my weight before,

0:46:24 > 0:46:29so I honestly think that there was something in

0:46:29 > 0:46:32my daughter's faeces that was causing me to gain the weight.

0:46:32 > 0:46:35It is very frustrating when you're used to looking

0:46:35 > 0:46:37and feeling a certain way,

0:46:37 > 0:46:39and then something like gaining weight

0:46:39 > 0:46:43can make you feel and look completely the opposite.

0:46:50 > 0:46:52The idea of bacteria in faeces causing weight gain

0:46:52 > 0:46:54may sound far-fetched.

0:46:56 > 0:46:58But the scientific detective work of Teresa's doctor

0:46:58 > 0:47:01unearthed some tantalising evidence.

0:47:02 > 0:47:04Well, when she initially came back,

0:47:04 > 0:47:07I didn't at first recognise her, even.

0:47:07 > 0:47:10She looked so different than I remembered her.

0:47:11 > 0:47:15Just like Teresa, Dr Colleen Kelly believes that

0:47:15 > 0:47:18the donor faeces holds the key to the mystery.

0:47:18 > 0:47:22The mother was slender and fit, and the daughter was overweight.

0:47:22 > 0:47:24Quite overweight.

0:47:24 > 0:47:26We didn't weigh her or measure her,

0:47:26 > 0:47:29but one would say maybe, possibly obese.

0:47:29 > 0:47:32At the time, we had some health criteria

0:47:32 > 0:47:35and some screening we would do, but obesity wasn't one of them.

0:47:35 > 0:47:40And a study published in 2013, looking at an unusual set of twins,

0:47:40 > 0:47:42and the effect that their faeces had on mice,

0:47:42 > 0:47:45seemed to provide the missing piece of the puzzle.

0:47:46 > 0:47:50They looked at twins who were discordant for obesity.

0:47:50 > 0:47:53So these were identical twin females,

0:47:53 > 0:47:56where one twin was obese and the other twin was lean.

0:47:56 > 0:48:00They would basically take stool from the obese twin and stool

0:48:00 > 0:48:04from the lean twin and then transfer that stool into germ-free mice.

0:48:04 > 0:48:11Mice that got stool from the obese twin developed more weight gain,

0:48:11 > 0:48:12more body fat,

0:48:12 > 0:48:17and those that got stool from the lean donors stayed lean.

0:48:17 > 0:48:22I think it was that landmark study that got a lot of press

0:48:22 > 0:48:25that really made me think, "Wow, is this what happened to Teresa?"

0:48:25 > 0:48:27We cured her C.diff, but did we transfer some

0:48:27 > 0:48:32bacteria from the daughter that may have promoted obesity?

0:48:32 > 0:48:37I wish that there was a way that I could undo it, some way that I could

0:48:37 > 0:48:41find a lean donor for her, and do a faecal transplant with a lean donor.

0:48:42 > 0:48:46To see if it would reverse or make any sort of effect.

0:48:49 > 0:48:53The Food and Drug Administration in America won't allow Colleen to

0:48:53 > 0:48:58do this, but an hour up the road at Brigham Women's Hospital in Boston,

0:48:58 > 0:49:01a human trial is about to start that could offer some hope.

0:49:04 > 0:49:07I'm just inserting the scope now into the rectum.

0:49:07 > 0:49:09- You OK, Jen?- Yep.- Great.

0:49:09 > 0:49:11And now what I'm going to be doing is

0:49:11 > 0:49:14making my way around the colon until I get to the end.

0:49:15 > 0:49:19'Today, Dr Jessica Allegretti is treating a patient with C.diff,

0:49:19 > 0:49:22'using a faecal microbiota transplant.

0:49:23 > 0:49:27'It is the same procedure that she will use in the upcoming trial.

0:49:27 > 0:49:29'But in the trial,

0:49:29 > 0:49:33'instead of transferring faeces into sick C.diff patients,

0:49:33 > 0:49:37'she will be treating otherwise well obese patients.

0:49:38 > 0:49:40'And the faeces will come from donors

0:49:40 > 0:49:42'with one key thing in common.'

0:49:42 > 0:49:45So what we are targeting are donors who are very lean,

0:49:45 > 0:49:50donors with BMIs of less than 20, somewhere between 17 and 20,

0:49:50 > 0:49:53who are otherwise healthy and very metabolically healthy.

0:49:54 > 0:49:58'Jessica hopes that the lean donor faeces will be packed

0:49:58 > 0:49:59'with fat-busting bacteria.'

0:50:00 > 0:50:03- How many bacteria do you think are in 250ml?- Oh, billions.

0:50:03 > 0:50:06Billions on billions.

0:50:06 > 0:50:10'The aim of the trial is to discover if the lean donor faeces will

0:50:10 > 0:50:14'influence the obese patient's hormones that affects hunger.'

0:50:14 > 0:50:17So what we're hoping the faecal transplant will do

0:50:17 > 0:50:20is, by giving good bacteria to patients with obesity,

0:50:20 > 0:50:25we'll be increasing certain levels of bacterial by-products that

0:50:25 > 0:50:28therefore influence hormonal levels in the gut and actually help people

0:50:28 > 0:50:32to feel more full, and therefore will influence weight loss.

0:50:32 > 0:50:35This is the last little bit of push, OK, Jen?

0:50:35 > 0:50:38Just going to give you a little bit more meds, OK?

0:50:38 > 0:50:39You're doing awesome.

0:50:39 > 0:50:42So we have just entered the large intestine

0:50:42 > 0:50:46to the small intestine, and this is where...the part of the intestines

0:50:46 > 0:50:50where the hormones come from that influence food intake.

0:50:50 > 0:50:52That make you feel fuller.

0:50:52 > 0:50:55Stool's coming out, it kind of blurs your vision.

0:50:55 > 0:50:59- So we're just kind of bathing the wall with that donor material.- OK.

0:51:01 > 0:51:04'And there's one hunger hormone in particular that Jessica

0:51:04 > 0:51:07'and the team will be keeping a close eye on - GLP-1.'

0:51:09 > 0:51:13So what we are hoping to see is that GLP-1 rises significantly

0:51:13 > 0:51:16after faecal transplants in these patients,

0:51:16 > 0:51:19and we're using that as sort of a surrogate marker for weight loss.

0:51:19 > 0:51:22And, if that is what we see, then I think it will be

0:51:22 > 0:51:26good evidence to support a much longer study that will be needed

0:51:26 > 0:51:29to really assess if this could work for weight loss.

0:51:29 > 0:51:31- Is that it?- Yeah. - Oh, good, we're done.

0:51:31 > 0:51:33Oop.

0:51:33 > 0:51:36That was amazing to watch.

0:51:36 > 0:51:40It is amazing to think that one person's faecal matter,

0:51:40 > 0:51:43one person's poop, can then help someone else feel better.

0:51:43 > 0:51:46If we can imagine that, in the future, this could be

0:51:46 > 0:51:50therapy for obesity, well, how wonderful would that be?

0:51:54 > 0:51:57The outcome of the trial remains to be seen,

0:51:57 > 0:52:01but even if successful, using faeces to deliver

0:52:01 > 0:52:05a full overhaul of a person's gut bacteria remains a radical solution.

0:52:05 > 0:52:10Which is why some scientists are taking a different approach.

0:52:10 > 0:52:12They are attempting to isolate individual bacteria

0:52:12 > 0:52:14linked to weight loss.

0:52:27 > 0:52:30For the final leg of my road trip, I am back in the UK,

0:52:30 > 0:52:32at St Thomas' Hospital in London.

0:52:34 > 0:52:36Professor Tim Spector is using faeces

0:52:36 > 0:52:39collected from thousands of sets of twins to

0:52:39 > 0:52:42try and identify which bacteria might make you thin.

0:52:44 > 0:52:46Twins are the perfect way to find out

0:52:46 > 0:52:50if something is due to nature or nurture.

0:52:50 > 0:52:53Whether it is inherited or due to our environment.

0:52:53 > 0:52:56What Tim has discovered about the bugs living inside us

0:52:56 > 0:52:59could revolutionise the way we treat obesity.

0:52:59 > 0:53:03There was this one bug, which stood out as the most heritable,

0:53:03 > 0:53:07which turned out to be extremely interesting in terms

0:53:07 > 0:53:09of its effect on body fat.

0:53:11 > 0:53:14Of all Tim's twins, non-identical Wendy and Carol

0:53:14 > 0:53:17have one of the largest weight differences.

0:53:17 > 0:53:22Wendy weighs 14st, and Carol just eight.

0:53:22 > 0:53:24Tim thinks that the bacteria

0:53:24 > 0:53:27in their faeces could provide clues as to their large weight difference.

0:53:27 > 0:53:29Thank you very much, fantastic.

0:53:31 > 0:53:34When we looked at thousands of our twins,

0:53:34 > 0:53:36the one thing that stands out between

0:53:36 > 0:53:38the fatter twin and the thinner twin

0:53:38 > 0:53:42was this funny microbe with a strange name,

0:53:42 > 0:53:44called Christensenella.

0:53:44 > 0:53:47And about one in ten people have it and, if you have it,

0:53:47 > 0:53:52- large amounts of it, you rarely get fat.- Really?

0:53:52 > 0:53:56- But...- And one of you has got it. And guess...

0:53:56 > 0:53:57Guess who it is.

0:53:59 > 0:54:04So Carol ends up having large proportions, about 5%,

0:54:04 > 0:54:06of Christensenella in her gut microbes.

0:54:06 > 0:54:09Whereas you have only got a tiny fraction,

0:54:09 > 0:54:11we can just about detect it.

0:54:11 > 0:54:14- Oh, wow.- But it is not doing very well in you.- Oh, is it not?

0:54:14 > 0:54:17Is there anything I can do to increase it?

0:54:20 > 0:54:23'Luckily for Wendy, Tim believes there is.

0:54:25 > 0:54:28'While her genetics may not have helped her Christensenella flourish,

0:54:28 > 0:54:30'what she eats could.

0:54:30 > 0:54:34'Studies have not yet been done to investigate which foods

0:54:34 > 0:54:36'increase Christensenella numbers.

0:54:36 > 0:54:39'But Tim believes that the right diet could encourage a broad

0:54:39 > 0:54:41'range of bacteria to grow.'

0:54:43 > 0:54:47The more diverse the foods, the more high-fibre the foods,

0:54:47 > 0:54:50the more species of microbes you're going to get

0:54:50 > 0:54:52and the more likely you're going to get the good ones

0:54:52 > 0:54:55rather than the bad ones flourishing.

0:54:55 > 0:54:58The base of this is really an old-fashioned Mediterranean diet,

0:54:58 > 0:55:01but without the pasta and the pizza.

0:55:01 > 0:55:06So it is plenty of fruit and veg, and you have got artichokes here.

0:55:06 > 0:55:09- Oh.- They are fantastic fertilisers for your microbes.

0:55:09 > 0:55:14It's also some things that you may not have thought of necessarily

0:55:14 > 0:55:19as healthy, you got dark chocolate - it is actually good for you.

0:55:19 > 0:55:21In moderation.

0:55:21 > 0:55:24Full-fat yoghurts, that is going to be really good

0:55:24 > 0:55:27for your microbes, because that contains healthy microbes,

0:55:27 > 0:55:30which energise your existing ones.

0:55:32 > 0:55:34Tim believes that manipulating these bugs opens up

0:55:34 > 0:55:37a whole new field of treatment for obesity.

0:55:39 > 0:55:42We are in the dawn of a whole new year of discoveries,

0:55:42 > 0:55:45and working out what makes these bugs tick

0:55:45 > 0:55:48and how they interact with us, not just this Christensenella,

0:55:48 > 0:55:51but there's likely to be other microbes just like it

0:55:51 > 0:55:52that are protective,

0:55:52 > 0:55:55and, if we can start to manipulate those through our diets,

0:55:55 > 0:55:59it's an extremely safe and potentially extremely effective way

0:55:59 > 0:56:03of fighting both obesity and its consequences like diabetes.

0:56:05 > 0:56:07I have just had a fascinating insight

0:56:07 > 0:56:10into the mysterious world of our gut bacteria.

0:56:10 > 0:56:14I now know that your genes, your environment, your diet

0:56:14 > 0:56:18all play critical roles in the type of bugs that will be in our gut.

0:56:18 > 0:56:22But it's still early days for the scientific research.

0:56:22 > 0:56:23Only time will tell

0:56:23 > 0:56:27if these bugs can lead the way in our fight against obesity.

0:56:37 > 0:56:41My road trip is over, and it is time to get back to the lab.

0:56:43 > 0:56:45I have covered thousands of miles

0:56:45 > 0:56:49and eaten more fast food than I would probably care to admit.

0:56:53 > 0:56:55I think one of the most precious things

0:56:55 > 0:56:58I will take away from this road trip is being able to meet people

0:56:58 > 0:57:03who are actually really quite debilitated by obesity.

0:57:03 > 0:57:07And it has given me an insight into obesity within the real world.

0:57:09 > 0:57:12It has really motivated me to go back into the lab,

0:57:12 > 0:57:14to try and redouble our efforts.

0:57:15 > 0:57:20Based on a lot of the cutting edge stuff we have seen on this trip,

0:57:20 > 0:57:24I am confident that this battle against obesity will be won one day.

0:57:25 > 0:57:28In the meantime, I will continue to make my own

0:57:28 > 0:57:31small changes in a bid to get my waistline back into shape.

0:57:32 > 0:57:36For example, I have got myself my normal morning cup of coffee

0:57:36 > 0:57:38and, instead of a cappuccino,

0:57:38 > 0:57:42I have got myself a black Americano with no milk.

0:57:42 > 0:57:45So a lot fewer calories and every little counts.

0:57:45 > 0:57:49I know that making changes like this is harder for some than others,

0:57:49 > 0:57:52but over time, the hardest-won battles

0:57:52 > 0:57:55can reap the sweetest rewards.

0:57:55 > 0:58:00At my heaviest, five years ago, I was 23.5st and had a BMI of 52.

0:58:00 > 0:58:02I am currently about 15st.

0:58:02 > 0:58:06I have lost 5st and I now feel amazing.

0:58:06 > 0:58:09I was 25st, I've actually now got down to 20.

0:58:09 > 0:58:11In 32 weeks, I have lost 4.9st.

0:58:11 > 0:58:14I'm a totally different person, I actually now

0:58:14 > 0:58:16take the dogs for a walk, which I have never been able to do.

0:58:16 > 0:58:19My life has just totally changed in those past five years.

0:58:19 > 0:58:21The people who haven't seen me

0:58:21 > 0:58:24in those five years just don't recognise me at all.