Episode 4 Trust Me, I'm a Doctor

TRUST ME I'M A DOCTOR FKR A470Y/03 BRD492018

We're constantly being told how to live our lives,

but what's the health advice you can really trust?

In this series, we use our expertise to guide you

through the contradictions and the confusions.

We'll get to the heart of the debate.

And ensure you get the information you need.

We're here when you don't know where to turn.

I'm Michael Mosley. In this series, I'm joined by a team of doctors -

together, we'll cut through the hype,

the headlines and the health claims.

This is Trust Me, I'm A Doctor.

'It's the end of January and most of us

'have started to let our new year health resolutions slip, so in this

'programme, we're going to test some cunning tricks to make them stick.'

Good looking guy. I'd trust him.

'Plus, we reveal the herbal supplement that could help

'you drink less.

'We'll find out why chocolate

'and ice cream could help some lose weight...'

-That just makes you think about food in a totally new way.

-Absolutely.

'..whether running outdoors or on a treadmill is better for you.

'And why the key to a good night's sleep might be pineapple.'

Ha-ha! This, I can't believe!

New year is traditionally the time

when we decide we're going to get in shape,

we're going to do that exercise, go on the diet,

take the cake out of the trolley and put it back on the shelf.

The problem is these resolutions rarely last.

By now, near the end of January, many of us

will have given up our healthy new year's resolutions and by the

end of the year, the figure will have risen to a shocking 80%.

We're here to help change all that.

When it comes to new year's resolutions, the themes remain

the same every year - broadly, eat better, do more exercise.

We know what we want to do, broadly we know how to do it,

the question is - how do we do it in a way that lasts?

How do we motivate ourselves to keep on going?

To find out, we're going to run a whole range of different

experiments throughout this programme to discover some

new tricks that could help us all stick to our resolutions

and improve our health.

To designs our tests,

we've assembled a team of behaviour experts at the Shard in London.

'Claire McDonald and Ed Gardner are leading our brainstorm.'

If it said, "After you've eaten these nachos, you really need to

"go for an hour run," then that might be something we could explore.

'It all comes down to understanding why we believe the way we do.'

Why do you think it is that people just find it incredibly

difficult to stick to resolutions?

There's lots of reasons and I think one of them

is related to what is pulling us to behave in a different way,

so it's easier to be inactive or eat more unhealthily,

then we're probably more likely to do that.

And we get distracted quite a lot.

The way our homes are built, the way we run our lives,

they're not always set up to help us act out that new behaviour

and if we are going to do it, we've got to change the way we live.

'So it's not that we lack the will to be healthier, it's just hard

'to alter our lifestyles in ways that really stick.

'But we want to change that.

'So we've come to Derby to test some of Ed

'and Claire's ideas on how people can stay motivated.

'For our first experiment,

'we've recruited 36 volunteers who all work here at Derby University.'

Morning, all. Hi there.

'Like most of us, they want to be a bit more active,

'but find it hard to motivate themselves.'

Are you kind of conscious of sitting quite a lot during the day?

Yeah, definitely.

I tried one of the fitness bands for a while and it kind of vibrated

when I'd sat for too long.

Do you classify yourselves as active or a bit inactive?

-A bit inactive.

-I'm not very active at all, I'm afraid.

I'm trying, but...

'We're hoping to turn trying into triumphing.'

We're asking our volunteers to put a bit more activity,

a bit more oomph into their daily lives.

And we're dividing them into three groups

because we want to test out three very different motivational

techniques and see which, if any of them, works.

'All three groups are being given the sort of information

'we hear all the time - take lunchtime strolls, get

'off the bus a stop early, and take the stairs, rather than the lift.

'But our experiment is about how well they stick to this more

'active lifestyle.

'So each group will try a different technique to remain motivated.

'Group one are the control group.

'They're just getting the usual familiar health messages.

'Group two will be our competitors.

'They'll be competing for prizes

'and will get regular feedback on their progress.

'Group three are the collaborators.

'We're giving them a team target

'which they have to achieve together.'

Now, with the control group, essentially,

they're kind of like the rest of us. They've got some information,

the standard sort of government information.

Do you expect that to make any difference?

I think we might see some kind of increase, yeah,

because we are providing them with prompts, but it is the kind

of standard prompts that we know and are given on a daily basis,

so information alone is not enough to change behaviour.

So I think we might see some kind of small increase, but potentially

not as great an increase as we see within the other groups.

Why did you choose the different approaches in the other two groups?

There's well established, I guess, findings that competition can improve people's

productivity and performance, so we're seeing whether or not it works in this office environment.

With cooperation, again, there's lots of evidence around, the role of social proof,

so actually if you see other people doing similar things to you,

or if people provide you with encouragement

or support in order to reach a particular goal,

then people are much more likely to commit.

I do like this. The uncertainty is quite fun.

It'll be very interesting to see which one wins. You think it'll be tight.

I think it'll be tight between the cooperation

and the competition, yeah.

-OK, I'm going for competition.

-OK.

Over the past week, we've gathered our volunteers'

baseline activity levels.

Now, we'll be keeping track over their progress over the next

four weeks with pedometers and apps to see which group is

the most successful at sticking to a more active lifestyle.

Will the urge to beat rivals or the dread of letting

a group down keep them more motivated?

We'll find out later in the programme.

Now, many of us make a resolution to cut back on alcohol.

A heroic few are attempting a dry January,

something that requires a supreme act of willpower.

But for those of us with the more modest aim of just cutting

back a bit on the booze, could there be an easier way?

Well, some brand new research coming from the United States

suggests that an ancient Chinese remedy might be able to help.

Surgeon Gabriel Weston's going to find out more.

This tablet is made from the root of the kudzu plant,

a type of vine native to South East Asia,

and there are some intriguing new studies that suggest that

taking it can help us reduce our alcohol consumption without us

even realising it.

It's a plant with a long history,

as Professor Elizabeth Williamson explains.

The ancient traditional uses, going back for 2,000 years, were for

coughs and colds and flu, also for blood pressure,

high blood pressure, hypertension, angina, quite a lot of things like

that, but it also has a long history of use for preventing alcohol abuse.

And what's its effectiveness against all those things?

It's used routinely in China for people with heart conditions

and that's been extensively tested. As far as the alcohol's concerned,

the history of that is documented back as far as 600 AD.

And it's not just ancient tradition.

There's some new scientific research that suggest kudzu might be

effective in curbing alcohol consumption.

But does that mean we should all start buying it?

I must admit I'm doubtful.

Sure, there are some tantalising

and reputable studies from Harvard no less,

but these were conducted on lone drinkers in laboratory conditions,

hardly equivalent to a boozy night out.

What we want to do is test kudzu in the wild,

so to speak, with a real life scenario

for the very first time.

We've recruited a group of volunteers from companies

in Reading willing to have two nights out in the name of science.

Two hours ago, we gave them all pills.

Some of them got kudzu and others a placebo.

None of them knows which they've taken.

Now, they're going to have access to our bar for 90 minutes

and can have their choice of beer, wine or spirits,

and we're monitoring how much each person consumes.

In America, studies have shown that taking kudzu makes people

drink more slowly and so drink less. This is thought to happen

because of a group of active molecules known as isoflavones

and the theory is that these isoflavones help deliver

alcohol to the brain more quickly,

so people feel its effects sooner

and hence, slow down.

But will this work in the real world?

One week later, our volunteers are back at the pub to repeat

the experiment.

Those who had the placebo last time have been given kudzu this time

and vice versa.

Again, they don't know which pills they've taken and we're monitoring

how many units they're drinking to see if the kudzu has any effect.

So, what do our volunteers think?

I felt like I was actually slowing down, compared to last week.

Pretty similar, really. Yeah.

-So no dramatic difference for you?

-No, not really.

-OK.

Well, tonight, I didn't really want to drink as much,

but I don't know whether that was because I wanted to or

whether because it's just cos of the drugs, I don't know.

So, guys, I've got the secret results in the envelope here.

When you were drinking as a group without kudzu,

just with a placebo, you had seven units per person

and when you took the kudzu, you had

5.5 units per person, which means

that overall, you drank about 20% less when you took the supplement.

It's a result.

I'm both surprised and encouraged by the results of our test.

I really didn't expect the kudzu to make such a substantial

difference, but before you rush out to buy kudzu extract,

it's a case of buyer beware.

Our test and those in the US involved each person taking

over 500mg of the active ingredient.

But we couldn't find any brands of kudzu available that had

the Government's THR mark that guarantees that they contain

what they say on the label.

We had to have ours laboratory tested to get the right doses

and they didn't contain the amount they said on the packet.

Maddeningly, then, there isn't yet a reliable product on the market.

But it's an enticing prospect, one that could make it easier to

stick to our resolutions and cut back on the booze.

Eating healthily, losing weight, these are all good resolutions.

The trouble is we're all different and it's unlikely that

a single diet is going to work just as well in everyone.

Dr Saleyha Ahsan has been to Israel to look at some really impressive

new research which suggests for the first time it is possible to

develop a truly personalised diet.

Some people can eat exactly what they want

and they never put on any weight, whereas others just need to

look at food and they're piling on the pounds.

'For years, we were told that this couldn't be true, that those

'who put on weight were secretly eating more, or exercising less.'

That smells gorgeous!

'Then we started to blame our genes.

'But now there's a new discovery which can explain this phenomenon

'and crucially, could help us all become healthier

'and slimmer without counting calories.'

A team here in Israel have found that different people do

react differently to different types of food

and what they've found is that it's not

so much to do with our genes, but our gut bacteria.

All of us have thousands of different microbes

living in our gut. They're key to how we process food.

And this new research suggests that our own personal

combination of bacteria can make a real difference.

'To find out how, I'm going to become

'part of a huge trial that's being carried out on 1,000 volunteers.

'First, I have to give a poo or a stool sample

'and I'm being fitted with a glucometer, a device which

'will measure my blood sugar levels constantly for the next week.'

Are you ready?

'When we eat, our blood sugar levels go up,

'but if they go up too high and too quickly in a spike, this can

'increase our risk of putting on weight and type 2 diabetes.

'Some foods have long been thought particularly bad at causing

'blood sugar spikes, but the researchers here now think

'those foods are different for each of us, as Dr Eran Segal explains.'

If we can understand which foods for individuals in particular

spike their blood sugar levels,

then we might be able to recommend for them

personally tailored diets that would achieve a normalised blood

glucose levels in these individuals.

So, why do you need a stool sample from me?

From the stool, we can actually extract the collection of gut

microbes that live there.

There's been many different studies showing the very intimate

relationships between us and our gut microbes.

If you take gut microbes from an overweight person

and from a lean person and you transplant them into mice,

the one who receives the gut microbes of the overweight

person will increase his body weight and become obese very quickly,

compared to the other who on the same exact diet will

actually not gain weight.

Oh, my gosh! Wow!

'Each one of us has our own unique set of gut bacteria

'and the theory is that this explains why different foods cause

'sugar spikes in different people.

'So I'm going to put that to the test.'

So I'm all kitted out now in exactly the same way as all the other

hundreds of people involved in the team's study.

They've got a sample of my gut bacteria and this little monitor

will be keeping an eye on my blood sugar levels throughout the week.

'Another volunteer, Leila,

'is starting the same experiment alongside me.

'We're the same sex and age and for the next week,

'we're going to do and eat all the same things.

'But both of us have different gut microbes,

'so will this make us respond differently to the same foods?

'A week of careful monitoring will tell us.'

Go to sleep. OK. There we go.

The next morning, Leila and I start the experiment.

'We're going to be following how our blood sugar levels react

'throughout the day to the same foods,

'using finger prick tests that give an instant result.'

-Right. Breakfast. I'm actually hungry.

-I'm starving.

'The researchers have given us a really exciting breakfast -

'four slices of white bread.

'This, according to the textbooks...'

Ow!

'..should cause us both a rapid spike in blood sugar levels.'

Mine's 99.

88. Quite a big difference, though, isn't it?

So, I'm having a little bit of a... On my graph, it'll be going up.

'So, I had the expected spike. Not good for me.

'But Leila's blood sugar remained at a lower, healthier level.'

# Me and you just singin' on the train,

# Me and you listening to the rain... #

'Over the next week, we'll continue to test our bodies' reactions

'to a whole range of common foods to find out

'which give each of us a bad sugar spike and which don't.'

I'm allowed to eat ice cream and I have to say,

after a hot morning's work, it's delicious.

And then we'll work out whether I'm ever allowed to have it again!

I'm going to make the most of it for now.

'From our results,

'the researchers will be able to relate our gut bacteria to the

'foods that give us a bad sugar spike and give us

'each a personalised diet plan to avoid them.

'But the team here think they can do even more than that.

'As Dr Eran Elinav, the project's other lead researcher, explains -

'they believe we can actually change our gut bacteria,

'giving us a healthier response to food.'

Eran, how can you actually change your gut bacteria?

So there's several ways which are under intense

research at our labs and nutrition is the strongest

influencer of the composition of and function of the gut microbes

so if we take, for example, an extreme situation in which

a person is eating meat and now he becomes a vegetarian.

And we have done such experiments in our labs.

You can measure the gut microbes and, within days,

there will be a dramatic, very reproducible change

both in the composition and the function of the gut microbes.

-You're training your gut microbes.

-Absolutely.

This is exactly like training your muscles.

It is training your other organ, which is our gut microbes.

-I mean, this is just so exciting.

-I am super excited.

This field and these findings are what keeps...gets me up at night!

The idea that food affects us

so differently and that we can alter that effect is brand-new to me.

I'd accepted the view that some foods gave all of us

a sugar spike and others didn't but, during this week,

I've already begun to see hints that this isn't quite true.

So I'm really looking forward to seeing what the entire picture

looks like with all of my results.

I'll be getting my personalised diet results a bit later

in the programme, seeing what it does for me, and finding

out more about the implications of this research for all of us.

Another common resolution is to get more sleep.

We all know how good it is for us,

but if we have real problems sleeping,

it can be a very hard nut to crack.

But we've got some new tricks you can try.

Over to Dr Chris van Tulleken.

I'm a lousy sleeper and it's getting worse as I get older.

You know, I wake up in the middle of the night more,

then I'm tired during the day,

so I have a nap, usually through something important,

that stresses me out, then I can't get to sleep at night.

It's a really lousy pattern.

Getting into bad sleeping habits can have serious effects on our brains.

So how can we break them?

To put our theories to the test, we found a place where

there are plenty of people suffering from problems sleeping -

a retirement village.

As we get older, problems with sleep get worse.

Time we went to bed, between 10 and 11, I was wide awake again.

And it would be three, four and five o'clock before I'd go to sleep,

tossing and turning.

I've started recently getting up four or five times a night.

Sometimes I'd be wide awake at two o'clock in the morning.

And I wouldn't go to bed till six o'clock, seven o'clock.

These are classic patterns of bad sleep.

And whether you're stressed

or getting older, the cause is the same.

It's down to your hormones, especially one called melatonin.

This hormone should naturally be released into our brain

when night falls, making us feel drowsy.

Dr Manny Bagary explains.

This is a melatonin curve of a young adult.

As you can see, round about seven o'clock,

the melatonin levels start to increase up until about three,

four o'clock in the morning, at which they peak

and then start to decrease.

And melatonin is the hormone that puts me to sleep.

Yeah, it helps you to go to sleep.

OK, why does our sleep get worse as we get older?

So, as we get older,

the peak in melatonin often comes a little bit earlier,

so we tend to sleep a little bit earlier

and we also tend to wake up a little bit earlier.

'So to tackle our volunteers' problems

'we're going to start by measuring their melatonin levels.

'Charmingly, we collected their spit at regular intervals

'throughout the day until they fall asleep.'

Thanks a lot(!)

We're also tracking their sleep patterns through watches that

monitor their movements and through detailed diaries.

After a week, Manny analyses our volunteers' data.

For some, it's clear from their melatonin patterns

that their body clocks are all wrong.

Tony shows a classic pattern for older people,

with his melatonin peaking too early, around 8pm,

sending him napping.

But his melatonin then drops again when he should be going to bed.

Billy, instead, has very low levels all night and can't get to sleep.

And then it suddenly peaks in the early morning,

which is when he finds himself finally dropping off.

'We, though, have researched a whole raft of ways that might help

'get their body clocks back on track,

'boosting melatonin at the right times and helping with sleep.

'And I've prepared each of our volunteers

'a Trust Me sleeping bag with instructions.'

-There you go.

-Cheers.

'The regime, surprisingly, starts in the morning.'

That's the last thing I need!

'They're not allowed to lie in.

'They must get up and open the curtains to get bright sunlight.

'Sunlight helps set the body clock,

'suppressing melatonin production in the brain.

'This should help make them alert for the day.

'Caffeine in the morning is fine, but not after 3pm.'

Decaf tea.

'Afternoon naps are strictly forbidden.

'The supper menu - a few unusual things to try,

'even though there's less evidence for them.'

Pineapples actually contain melatonin.

It's a bit of a long shot

as to whether or not they'll put you to sleep, but if you're

desperate and you like pineapple, well, it might be worth a go.

Oh, wonderful.

'And there are other melatonin-containing alternatives

'such as rice, walnuts, sweetcorn,

'banana, orange and a warm, milky drink.

'After supper, it's no alcohol and complete darkness.'

What's this? A sleep mask.

'Even the blue-tinted light from computer screens

'and TVs can suppress melatonin that should be being released

'into their brains and helping put them to sleep.

'Our volunteers have agreed to stick to this routine for a week

'whilst we continue to monitor their sleep and melatonin levels.

'So how have they got on?'

I pretty well liked what was in the bag.

I'm a very happy bunny.

I really did lay off having coffee in the evening.

I did try to take my half-glass of hot milk

and I think that made a difference, too.

So, Manny, what were the results?

The results were very interesting.

Most people seemed to get better but those changes really

seemed to come through towards the end of the week.

And three people got significantly better.

For example, at the start, Kerry's melatonin levels

were very low through the night,

linked to her problems sleeping.

But now her cycle has returned to normal.

I tried doing the things that were on the list.

I ate the foods at the right time.

I'm going to make sure that she doesn't drink

-as much coffee any more. She does.

-And the wine.

-Can't stop the wine.

-No, no, the wine can be medicinal, but coffee, no.

-Ooh!

And Beryl's sleeping patterns show that she woke up fewer times each night.

One of the articles you gave us and told us was to block out light.

And I did that, and that was a great help.

Some of the other things we tried were rather experimental,

but others have good scientific backing behind them

and some of them, at least, seem to have had an effect.

The results based on one week's intervention are very impressive.

We would expect improvements to bed in

over a period of six to eight weeks.

Is anyone going to keep up any

of the advice or interventions that we have given?

Yes, because it helped.

Instead of three, four, five o'clock in the morning,

I can go to sleep now straightaway.

I think we are definitely sleeping better

because of what we have learned, what we have been shown.

There is evidence that better melatonin patterns

and sleep might do all our brains good, too,

helping keep us sharp.

You know, I think a lot of us just accept,

as we get older and we get more stressed,

we're just never going to sleep that well again, but there is this what

I think of as a kind of bundle of changes you can make in your life.

These might help restore your melatonin and sleep patterns

so that you don't just feel better, your mind will stay sharper, too.

There's information about all the tricks you can try to sort

out your body clock and melatonin levels on our website...

The hardest thing about getting healthier isn't knowing what

to do, it's actually going out and doing it and then sticking to it.

And that's why we've set off a whole array of experiments here in Derby

to see which, if any, help people achieve their health goals.

Morning, all!

'In the university offices,

'36 volunteers have set out to get more active.

'We're testing whether competing with each other or cooperating to

'achieve a group target is better to keep them motivated.

'My resolution, though, is around food.

'Whenever it's there, I'm tempted to eat it, especially if it's sugary.

'So how can I get better at resisting temptation?

'Well, there is research that suggests

'a few simple tricks might make a big difference.'

Experts from Cornell University in the United States have done

some absolutely fascinating research looking at the links

between our weight and the foods we leave lying out on the surface.

And based on studies in hundreds of kitchens,

they've come up with some golden rules

of what to do and what not to do.

First, put all food out of sight...

..apart from fruit.

What the experts found was that people weighed more on average

if they kept things like biscuits, fizzy drinks,

crisps and even cereal on their kitchen counters, whereas those

with just fruit on the counter were more likely to weigh less.

The trick here is to avoid temptation altogether.

What I'm doing is out of sight and out of mind.

But, in reality, I am such a chocoholic that I'd actually have

to give this to my wife to hide, otherwise I would go and eat it.

Next, reorder your cupboards.

It turns out we are all naturally a bit lazy and are three times

more likely to eat the first foods we see than the fifth one.

So put healthier foods first.

And take vegetables out of the drawers at the bottom of the fridge

and put them where you can see them.

Then there's the eating itself.

When I cook a family meal like a casserole, I would normally

leave it on the kitchen table for people to help themselves.

Well, it turns out this is actually a really bad idea.

In studies we have found that, if you leave

the casserole on the stove, then people will actually 20% less.

Why? Well, we don't just eat when we're hungry,

we eat what is in front of us.

So if you leave it over there, then people are far less likely to

help themselves to unnecessary seconds, or even thirds.

The trick is to understand that we naturally tend

to go for the easy option and make that the healthy option.

Which is all very well in the privacy of our own homes,

but what happens when we head out shopping?

'There, it seems, the whole world is designed to make us

'buy more food, and often less healthy food.

'Well, behaviour expert Claire McDonald has some tricks for us

'to try there too.'

The shopping environment has been designed to help us

conveniently move around a store in a kind of mindless fashion.

A fog head. You'll have the similar items week in, week out,

and how they get into your basket isn't necessarily choice,

it's just repetition, habits.

We get into a way of shopping.

'And she's unearthed some possible ways of breaking those bad habits.

'But they require rather unusual experiments

'at an obliging local supermarket.

'Firstly, can we be nudged into healthy habits

'if caught at the right moment...'

Good-looking guy! I'd trust him.

'..with unexpected messages and reminders at the right time?'

We're going to remind people as they go round the store,

so they don't get lost in the kind of mind space of shopping.

They're going to be prompted continually.

So by putting a prompt right by the fruit and veg,

you can act upon the message as you receive it.

So, soon there could become more cut-outs of me

-scattered all over the country!

-A terrifying thought.

An army of Michaels across the country

telling you to eat fruit and veg.

And we're also testing a new theory,

that what we eat just before we shop will influence our buying habits.

We've probably all suffered from shopping while hungry,

but how about shopping while eating?

Over the next few weeks we're going to monitor the sales of fruit

and vegetables in this shop

and see if our interventions have made any difference.

If they have, and even if they haven't,

we should learn some valuable lessons.

'And when the results came in, they were encouraging.

'Compared with similar stores,

'this one had an 8% increase in vegetable sales over six weeks.

'It seems that reminders at the crucial time really helped.

'And when we encourage people to eat clementines before shopping,

'clementine sales went through the roof.

'Not a surprise to marketeers, perhaps,

'but something we could turn to our advantage.'

Thank you!

'So when you're hitting the food shops, use your own psychology.

'Don't go snacking on chocolate and crisps just beforehand

'if you want to avoid buying more junk.

'And use the power of the timely reminder.

'You don't need a life-size cut-out of me.

'A note to self on shopping list should do it.'

'Earlier in the programme I was in Israel...'

Are you ready?

'..taking part in a new study that promises to revolutionise

'the way we think about foods.

'The researchers there believe that what's good for one person

'can be bad for another

'because of differences in the bacteria we all have in our guts.

'If true, this could change diet advice for ever.

'To put it to the test, both I and another volunteer, Leila,

'ate exactly the same things for a week.

'The researchers analysed how those

'foods affected our blood sugar

'levels and how this in turn related

'to different bacteria in our gut.

'Dr Eran Segal is about to reveal our results.'

Basically, we have analysed everything that you ate.

So there are certain items that we identified as being good,

and good in the sense

that they do not raise your blood sugar levels much.

-OK.

-And we can put that into categories of things that are...

I'm already seeing things that I love that are on the bad!

Oh, no!

Cereal, grapes, tomato soup

and sushi all turn out to give me

a bad spike in blood sugar levels,

increasing my risk of type 2 diabetes and putting on weight.

I thought I was being healthy.

I thought, "Right, I've got grapes. I'll just snack on grapes."

And as I've been doing that I've actually been contributing

to my glucose levels spiking and getting fatter.

But cola, ice cream, chocolate and croissants are all on my GOOD list.

It's all very surprising.

-I haven't bought a loaf of bread for years.

-Really?

I can't believe that.

'And compared to mine,

'Leila's results

'just go to show

'how different individuals are.

'Several foods, like croissants,

'bananas and nuts, pasta and pizza,

'had opposite effects

'on the two of us.

'And this means that standard

'healthy eating advice

'is doing some of us

'no good at all.'

Wow!

I'm so surprised.

This is showing you the results on two individuals,

but we've tested close to 1,000 individuals.

And, for example, if a dietician tells somebody

to eat wholegrain rice,

and we see that many people actually spike for rice

and they don't know it,

then that advice can actually have harmful effects in the long run.

Yeah.

'But the team think that knowing our gut microbes could help.'

When comparing you and Leila, we actually found very big

differences in your microbiome composition.

Leila has a good bacterial composition

that is much more diverse.

-She's got more colours.

-More colours.

And in general, more colours

and more diversity of gut bacteria is a good thing to have.

So if I follow the diet that you've given me,

-then I could end up with a more colourful pie chart.

-You might.

And then perhaps, after altering your good bacteria,

your response to foods might actually improve overall

and your glucose metabolism might improve overall.

'These results are fascinating

'and clearly I have to try what the researchers are suggesting.'

Looking ahead -

and I am so excited about this -

I'm going to stick to the good food diet, I'm going

to avoid the bad food diet and then we're going to re-test

for my gut bacteria to see if there's been any difference.

And according to Eran, there should be.

So for two weeks, it's out with the red foods and in with the green.

Meanwhile, back in Israel, the team are analysing my gut bacteria

in stool samples I send them.

Now it's time to find out what they've seen.

-Hi, how are you doing, guys?

-Good.

-We're good.

What I'm dying to know is, how were my results?

Your microbiome configuration dramatically changed.

And in most aspects it changed for the better.

We saw that certain bacteria that are typically associated with

-a risk for obesity and diabetes became lower.

-Really?

We can see that certain bacteria that are associated with

-improved glucose tolerance, they actually went up.

-That's amazing.

-And actually over a really short space of time.

-Absolutely.

The results are incredibly promising.

If I keep to the personalised diet,

my gut bacteria should

continue to change.

My health should improve

and I may even lose some weight.

This research is truly revolutionary

and has the potential to transform

our health in the future.

I'm so excited by what I've just been told.

In the space of just a few weeks, I've managed to change my own

gut microbiome profile.

This experience is going to change my life,

and I hope in the future it will help other people too.

The team in Israel are now working on a way to allow anyone to

send in a stool sample and get a personalised diet plan in return.

And they are currently running a study over a year to see how

long you need to stay on the diet to maintain the healthy changes

in your gut bacteria.

There are more details on our website at...

Still to come, could your scales really be lying to you?

And is there such a thing as too much exercise?

But first...

For those of us whose resolution is to get more exercise,

running is a very popular option.

But is there really any difference between treadmill running

and outdoor running?

And which one is better for our body?

I'm going to try pounding the pavement

and toiling on the treadmill to find out.

First, does one of them get me fitter than the other?

Well, there's a decent chance you're burning more calories

if you're out in the open air.

Running outside actually uses up more energy than

running at the same speed on a treadmill.

This is largely due to wind resistance,

which you just don't get running indoors.

However, a study conducted at the University of Exeter shows

that you can easily compensate for this in the gym

simply by setting your treadmill to a 1% gradient.

But there's also the issue of perception.

A study from 2012 found that the treadmill can

distort our perception of speed.

When participants were asked to match their outdoor running speed

on a treadmill, they ended up running significantly slower.

This suggests that not only do we work harder

when we're running outside, we don't even realise we're doing it.

So if running edges it in terms of work rate,

what method is safest for our bodies?

When it comes to injuries, there are fewer hazards to treadmill running.

But there are also some surprising drawbacks.

Repetition of the same movement can put us at a grater risk

of wearing out joint or ligaments and ending up with an injury.

When we run, each foot hits the ground about 1,000 times per mile,

leading to a lot of wear and tear.

So if you use a treadmill,

where you're performing the same action again and again,

it's a good idea to mix it up a bit by varying the speed and incline.

This is less of an issue in the great outdoors.

When you run outdoors, especially if you go off-road,

each step is likely to be different because of the uneven

and varied terrain, and this can actually strengthen the ligaments,

activate a variety of muscles and even teach the body better balance.

Studies have also shown that exercising outdoors

is good for the mind and for lowering stress and blood pressure.

Plus there are the advantages of exposure to the sunshine

and therefore to vitamin D,

although in Britain that clearly can't be guaranteed.

For strength, fitness and well-being,

outdoor running clearly has the edge and it costs nothing.

But if you prefer the treadmill, make sure you take advantage

of all its features to up the energy levels and ring the changes.

But when you're enthusiastically getting your exercise,

can you overdo it? Is there such a thing as too much exercise?

The current government guidelines for adults are

150 minutes of moderate exercise a week.

But is this the best amount for us or just the minimum?

Michael is finding out.

I've come to hear the opinions of two of the world's leading

experts on exercise and they have very different views.

In the blue corner is Professor Sanjay Sharma.

He thinks the guidelines are spot on.

150 minutes, let's call it max 200 minutes per week,

is enough for the welfare of the general population.

And in the red corner is Professor Alejandro Lucia.

He thinks we should be doing much more.

Maybe 450 minutes per week would be ideal.

I want to find out why they have such different views.

First up, Professor Sanjay Sharma from St George's Hospital, London.

He is the medical director for the London Marathon.

He's convinced there is such a thing as too much exercise.

Over the last two decades or so, there has been emerging evidence

that in some individuals too much exercise may be deleterious

to an individual who otherwise had a normal heart.

Postulations are that too much exercise may cause the atrium,

the top chamber of the heart,

to stretch or to even become inflamed

and scarred, such that the electrical circuit through it

doesn't work very well, which is called atrial fibrillation.

Now, some people would say this is only going to happen in people

who already have some sort of pre-existing weakness or disease,

that you can't make a good heart bad by doing exercise.

Well, we took 172 veteran athletes, mean age about 52,

we compared them with matched individuals who lead a healthy lifestyle.

We found that our athletes, 15% of our athletes,

had scarring in the heart muscle compared to none of our controls.

43% of our athletes had furring up of the arteries compared with

only 23% of our controls.

So I don't think for one second that the more you exercise,

-the longer you will live.

-What would you recommend?

I would say 30 minutes a day,

equating to 150 minutes per week.

This has been derived from very large studies of 45,000 males.

And that kind of gives you probably the sort of optimal health benefits.

I do believe this 150 to 200 minute cut-off

that we're talking about is enough to give you at least

three additional years of life.

If we packaged exercise up into a pill, it would be considered

as a miracle pill, because there is no other therapy that's been

invented yet that quite has the benefits of exercise.

I should also say that these benefits

go beyond the cardiovascular system.

Exercising reduces the risk of cancer of the colon,

cancer of the prostate, it retards the ageing process,

and it is an antidepressant.

And what would you recommend?

If you were going for a single form of exercise, what would it be?

I would say a brisk walk.

A brisk walk can be done any time, you don't have to pay

to go to the gym, it can be performed anywhere, anyplace

and it's enjoyable.

Professor Sharma clearly believes that, although exercise is

great for our health, there is such a thing as too much.

But is he right?

Professor Alejandro Lucia has carried out studies into the health

of elite athletes and authored more than 350 scientific papers.

Now, the standard recommendations are that we should be doing

150 minutes of moderately vigorous exercise every week.

How much do you think we should really be doing

if we want to get optimal benefits?

I will say that...maybe 450 minutes per week would be ideal.

450 minutes a week is a lot!

I mean, that's almost 70 minutes a day.

How much do you do?

I do indoor cycling two or three times a week fairly intensively

and then I ride my bike for four to five hours on Sundays.

-Four to five hours?

-Yeah.

-OK.

-And then...

-That's impressive!

So do you think you can damage a healthy heart

by doing too much exercise?

I don't think that intense exercise, even at the highest level,

if done properly, should damage a previously healthy heart.

So you frequently hear about people dropping dead in a marathon.

Yeah, there was

a NICE study done by American researchers a few years ago.

They analysed data from 10 million runners who ran

marathons and half marathons in the US in the last decade.

And they found that the incidence of sudden cardiac death

was fairly low.

And, when it happened, it always did in the less prepared runners

and during the second half of the race.

These people had never even done a half marathon before

and they had an underlying cardiac condition,

which had remained unrecognised until that moment.

So Professor Sharma would argue that, if you do a lot of exercise,

then you can cause permanent damage to your heart. What do you say?

We did a couple of studies, the cohort was fairly small

on former world champions in marathons or Tour de France cyclists

and we didn't see any type of deleterious affect with MRI.

There was a good balance between the muscle mass

and the size of the cavities of the heart.

But is there any real evidence that elite athletes actually live

longer than the rest of us?

Yeah, they do live longer than the rest of us,

especially those who have participated in endurance sports.

For instance, there was a study published on

almost 100 cyclists who finished the Tour de France

and they lived quite longer than the general population.

Doctor Lucia sees government guidelines

as a bare minimum, not a target.

And he thinks there is no limit to how much exercise we can do.

As long as we are healthy, we will never damage our bodies.

Now it's my turn to decide, after hearing their evidence,

what I believe.

Now, everyone agrees that exercise is a good thing,

but how much is too much?

Well, having listened to our experts, I am inclined to think

that around 30 minutes of moderate exercise done most days of the week,

that's 150 to 180 minutes, is enough for most people.

And if you go on really hard for a long period of time, there is

a small but significant risk that you'll damaged not just

your joints but also your heart.

There's nothing more depressing than climbing onto the scales

after a week of dedicated dieting and seeing that your weight has

stayed exactly the same or, worse still, seems to have increased.

This can undermine all of our good intentions and leave us

reaching for the cake tin in despair.

But what if these disappointing results

aren't always what they seem?

What if it's the way that we are weighing ourselves

that's the problem?

Let's say you're trying to hit a sensible weight loss target

of half a kilogram a week. Sounds simple enough, but...

over the course of a single day,

our weight can fluctuate by as much as one or two kilograms.

'This is mainly due to things like eating, drinking, exercising

'and going to the toilet.

'So if you want an accurate measurement of weight loss,

'here's what you should do.

'Ideally weigh yourself naked.'

-I'm not taking my jeans off!

-No, no, don't worry about that.

-Is that where you're normally at?

-Yep.

Step on.

That's great, even with shoes and coat on. Right, your turn.

'Always use the same scales.'

-Happy, sad?

-Not surprised.

-OK.

'You should also make sure you place the scales on the same hard surface.

'Carpet can make a surprising difference.'

I know always my weight.

OK.

Right.

Go.

The reason that these scales are reading differently is

because the base is sinking into the carpet,

which means the carpet fibres are supporting some of the weight.

-That's nicer.

-That's nicer!

A lot nicer. Like 10... Yeah, 10 kilos.

Wow, wow.

For accurate results, weigh yourself every day at the same time.

Then, at the end of the week, calculate the average.

After a few weeks, you will have an accurate track of your weight.

A recent study in the US found that people who weigh themselves

every day are more likely to achieve their weight goal.

But if a daily weigh-in is a bit off-putting, do it weekly instead.

Choose the same day every week

and then calculate the average over each month.

So next time you step onto the scales

and get a nasty surprise, don't lose heart.

One-off measurements don't reflect your true progress.

Instead, keep going. Your hard work will pay off over time.

Paracetamol is in the news.

We take it for everything, from toothache to pulled muscles.

But recent headlines claim that, for back pain,

it's no better than a sugar pill.

They're reporting on a big study in a major scientific journal.

So what does this mean? Over to Chris.

The truth is, paracetamol has always been a bit of a mystery.

We've never been exactly sure how it kills pain.

And it turns out now that perhaps the reason we don't understand how

it works for things like back pain is because it might not work at all.

But for back pain, maybe that shouldn't be such a surprise.

We've known for a long time that paracetamol is not as effective

as anti-inflammatories at treating painful conditions where the

painful area is inflamed, like arthritis or a painful wound.

We also know it doesn't work very well

when pain is coming from the nerve itself, so things like sciatica.

And that might explain why it's not very effective for back pain,

because much back pain is due to inflammation and nerve pain.

Perhaps more importantly, though, there's another caution

about paracetamol, that there are questions about its safety

if you take it in the long term in relatively high doses,

something that you might be tempted to do if you have

a longer-term back pain.

But the good news is that paracetamol is probably still

effective for things like post-operative pain,

headaches, dental pain and of course it treats fever very effectively.

So don't be put off paracetamol completely.

Just use it sparingly and for the right things.

As for back pain, the National Institute for Clinical Excellence,

NICE, are reviewing their recommendations

and they'll consider this evidence when they report back.

In the meantime, if you have back pain or want to try something

different, there are drug alternatives.

But more importantly, there's exercise and physiotherapy

and you can speak to your GP about how to do those things best.

Back in Derby, it's the end of their big experiment.

For four weeks, our 36 volunteers have been trying to stick

to the resolution to get more active using different types of motivation.

One group, our control,

received nothing more than regular public health advice.

The second group were competing

against each other for prizes.

And the third group had a collective

target to aim for together.

It seems some of them certainly found motivation.

Erm, use the stairs, never catch the lift.

Where I'd normally e-mail people, I would try and go and see them.

We had one day where we decided we just try

and do as many stairs as possible, so we started at the bottom floor,

up to the ninth, back down again for as many times as we could go.

But which group increased their activity the most?

Experts Claire McDonald and Ed Gardner have been monitoring all

their steps and their stair-climbing and totting up the winners.

First up, the control group.

Over the four weeks, their average activity levels

stayed pretty constant, just a 3% overall improvement.

The co-operators were much more active throughout

the experiment, a 16% improvement.

And finally the competitors,

well, they were similar to the co-operators

until the final week, when they had a burst of activity,

giving them a 30% overall improvement.

But then we looked at individual scores.

Although the competitive group contained the two tops scorers,

response from the rest of the group was more mixed.

These patterns give Ed and Claire a fascinating insight

into our psychology.

One of the things that we found was that those in the competitive

group appear to be increasing in the number of steps they were taking

from week to week, so they were improving on a week by week basis,

whereas those in the control and the cooperative groups

stayed relatively stable, so they just stayed flat over time.

So the people who are in the different groups,

they could see what other people in the groups were doing?

So the competitive group, yeah, they were told their position,

I guess, or their rank within their group each week.

Right, so as you slipped down the rankings, you might have said,

"Right, I'm going to improve," or something like that?

That's the idea - those below the normal, below the average,

should show or realise they need to improve

compared to the rest of the group.

That's what you find in the competitive group.

Whereas in the cooperative group, even those below the norm,

they're all in it together,

therefore actually people remain relatively stable.

So understanding a bit of psychology can help us

all stick to our resolutions.

I tend to go for the stairs now just by default, really.

-I don't think I've taken a lift since we started.

-It's very helpful.

I think if you try to do things on your own,

you tend to slip back into your old ways.

Doing things in a group is key.

It's social pressure that motivates us to stick to our resolutions

and not give up.

Now, certainly our activity experiment suggested that

involving other people is incredibly helpful,

probably because it's more enjoyable

and that means you're more likely to stick to it long-term.

For some people, competing with each other seems to be best.

For others, it's being in a cooperative group.

But whichever suits you personally, use that knowledge and any other

tricks from the series if you want to make yourself healthier.

Get the most benefit for the least effort...

..by exercising at the right time...

..and eating at the right time...

..knowing a few things to avoid in your life...

-It's a shocking result.

-It really, really is shocking.

..and a few things to get a bit more of.

The wider the hips, the more healthy you are.

That's it from Derby and this series of Trust Me,

though we will be back later in the year.

In the meantime, why don't you go and visit our website...

..where you can find out a lot more about everything

covered in this series and also sign up for some experiments.

# I just made an appointment for a special rendezvous

# To see a man of miracles and all that he can do

# Doctor, I want you

# Mmm, my doctor, wanna do

# I can't get over you, Doctor, do anything that you wanna do. #