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Pr Susan Jebb & Gary Frost: What’s new in research for treating obesity ?

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«What’s new in research for treating obesity?»

Participants :
Dr Susan Jebb, Head of Diet and Population Health at the Medical Research Council Human Nutrition Research Unit, Cambridge.
Professor Gary Frost. Chair of Nutrition and Dietetics, Head of Nutrition and Dietetic Research Group, Imperial College, in London


PETER GOODWIN:
Hello! Welcome to MD-FM — the first medical web radio. I’m Peter Goodwin.

Today’s MD-FM is actually a debate devoted to obesity, its increasing medical burden on society and the latest research on dieting and weight reduction.

We’ll be asking our speakers in the debate, what are the real reasons for increasing obesity in most countries? What kind of diets could help reduce this burden? What new treatments are there? And in practical terms, how can doctors effectively tackle the challenge of obesity in the community?

And I’m pleased to welcome our distinguished guests: Susan Jebb: and, Susan, you’re Head of Diet and Population Health at the Medical Research Council’s Human Nutrition Research Unit, in Cambridge — and as such, one of the top people in the country helping the government decide about these things.

Gary, your researching nutrition, you hold the Chair of Nutrition and Dietetics, at Imperial College here in London, and you’re Head of the Nutrition and Dietetic Research Group at Imperial with a million, it seems to me, fascinating research projects going on!

So, let me ask both of you, I don’t know who to start with, but Gary, scientifically, why are we all getting fat these days?

GARY FROST:
Gosh that’s a very big question to start with. I suppose we can come from it in many different ways, let’s take for example our genes. Where have our genes come from? They’ve come from an environment many years ago where we had to survive. So our genes are switched on to helping us survive and one of the critical things about that is eating.

PETER:
So we’re programmed to put on weight because we need to have a store?

GARY:
If we didn’t, if that wasn’t the case, the human race would have died out.

PETER:
So Susan what is it that’s changed on society that’s made it go into overdrive?

SUSAN JEBB:
Well if we’ve got this predisposition to eat and our hunger signals are very very strong, but in fact our fullness signals are much weaker, if we’re in a world where food is available pretty well 24/7, there is always going to be risk of people over consuming. And so yes obesity does simply come down to people eating more calories than they need, but of course that simple statement belies the complexity of reasons why people eat. You eat because you are genuinely hungry, there’s a biological urge to do that, or you might eat because you see an advert on television and it makes you think, I quite fancy that, you're not hungry but you desire it.

GARY:
The pleasure of eating is incredibly important…
SUSAN:?Absolutely!

GARY:
Again, we have a drive there to actually eat things that give us pleasure.

SUSAN:
But, we have to say that the rate of increase in obesity is far too rapid to be explained by some change in our genes. We have to look not to a collapse in will power across Europe but actually to changes in the environment, which means that it is now so much easier for people to over consume, and over consume actually a rather small amount each day but that builds up over a year to a very substantial amount…

PETER:
Its pretty catastrophic isn’t it because, one statistic I heard is for women, young women in their thirties are now seven kilos or so heavier than they were 20 years ago, that's in a place like the UK, that is really horrifying...
SUSAN:
There is an average increase of weight year on year, and its reduced slightly in recent years but we’re still getting fatter. And that’s something which is a problem because it brings with it a huge burden of ill health. I’m not worried what people look like, but I am concerned about their health and we know that obesity is underpinning so much of the disease that we’re seeing today.

GARY:
And just on a personal, anecdotal level, when I first qualified as a dietician in the early 1980s, you very rarely saw a young person with type-2 diabetes, type-2 diabetes was a middle-aged disease. Now, it’s a regular occurrence that a young teenager who is overweight or obese will turn up to the clinic with type-2 diabetes and that is devastating, and it’s devastating for the population.

SUSAN:
Here’s a couple of statistics which its worth doctors remembering, people on average who have a BMI of 30, that is the level of which we say they are clinically obese, have about 20 times the risk of developing diabetes. Or if you want to put it another way and think about absolute risks, for anybody under the age of about 45, if you have a BMI of 30, you’ve got a one in two lifetime chance of developing diabetes.

PETER:
I'd like to come back to some of those statistics later but, if Gary our genes have evolved in a hunter-gatherer society, we’re not hunting and gathering anymore so what are the methods we can use to loose weight?

GARY:
Gosh again you ask a very complex problem and we need to break it down a little bit, because you’ve got a population level intervention and then you’ve got what can you do with an individual, and the two might be very different. I think on a population level, my understanding is we’re struggling, to turn round this huge tanker of disease no one country at the present time has actually managed to achieve that.

SUSAN:
We’ve got a whole raft of public policies which are trying to make it easier for people to eat a little bit less. And what we’re looking for there is policies interventions which will effect the whole population but which will perhaps quite a modest effect. So that might be reducing the portion size of some of our popular snacks for example. But the other alternative or in fact complimentary strategy, is to focus in a more targeted way on people who are currently over weigh or obese, that’s the more clinical approach and perhaps one that doctors are more used to dealing with.

PETER:
We may often blame people for being over weight and imply that they’re doing something wrong, what might they be doing wrong?

GARY:
In very simple terms, they’re eating more or their energy intake is greater than their needs. Now again there’s a balance between, input so the food that we eat and output the amount of energy that we expend and between the two something has gone wrong.

SUSAN:
We need to be very careful about using the word blaming people when you’ve got in the UK two thirds of people who are overweight, you cant entirely say all of those people are to blame from what's happened. And I think we also know that blaming people doesn’t help them to tackle the problem. What people need is practical support, which will allow them to make those changes in their diet which we know are going to help them control their weight.
PETER:
I called in to see one of your colleges at imperial college professor Jimmy Bell recently and he was concerned that people were actually demonizing fat. Maybe we can listen to what he had to say briefly:

JIMMY BELL:
I think most of us have a very negative connotation of what fat does and why it’s there in our body, its what we call a demonization of fat, and fat is a very important organ essential for your life you cannot have optimal health without having fat in your body. So no one should aim at minimizing fat to zero, fat is required for many functions both for immune response, development, the way your brain functions so we need an amount of fat, its when that fat gets distributed in the wrong places or we have too much fat. So trying to maintain your weight as the ultimate measure of health, is the wrong thing to do, I think you need to have a physical activity as part of your lifestyle and that activity should include a method that will reduce internal fat rather than just maintaining a set weight.

PETER:
What do you make about those comments about demonizing fat?

SUSAN:
You’ve got to be very careful because what jimmy’s talking about is body fat, the fat we store in our body. And I think all scientists would agree that some fat is absolutely vital, its part of our body's metabolism. But even a very slim woman BMI of about 20, is going have about 20% of her body weight as fat, that’s more than enough to perform all of the metabolic functions. As you start gaining weight, what happens is most of the weight you gain about 75% of the weight you gain, is fat. And as you increase your body fat you start to incur the metabolic complications that that brings, insulin resistance, abnormal blood lipids and high blood pressure.

GARY:
And Jimmy’s absolutely right, that body composition does play a big role in this so having or gaining weight round your middle is perhaps worse for you than gaining weight on the hips but that’s a little bit pushing it...
SUSAN:
Its also very strongly genetic, where you deposit your fat is incredibly strongly influenced by your genes therefore the thing you can modify is not gaining weight.

GARY:?Jimmy’s bringing up the role of exercise and I think again we need to be very clear about what exercise can do in different states, because again I think we can have a debate about the value of exercise in people who have a BMI greater of 30 in weight loss…
SUSAN:
Well exercise is always going to help, it’s going to boost metabolic fitness and it may help you to control your weight, but for somebody who is seriously overweight it’s very very rare that they’re going to control it with just exercise.

GARY:
And we’re very efficient. The amount of energy you expend for a degree of exercise is relatively small.

PETER:
To actually do something about it the things doctors can do to help obese patients, sugar obviously is pretty important, people have a sweet tooth, it means they can get lots of carbs in very quickly and easily. What do you make of that and what should we be doing?

SUSAN:
If you want to eat fewer calories, then you’ve got to eat less of something and sugar is an obvious place to start because very often it brings calories into the diet without any essential nutrients, and sugary drinks would be the obvious example of that, you get calories but you get no micro-nutrients, so it’s a good way of cutting calories. But actually fat also brings a lot of extra calories into the diet, fat’s very energy dense, so in a small amount of fat, you can pack a huge number of calories.

GARY:
And our eating behaviour has changed, so if you look at what’s happening with young people there seems to be an increasing grazing behaviour over time so the amount of eating episodes we have is increasing, and if you look at what’s going on in those eating episodes, it tends to be high fat, high sugar foods and if you can get in and change that, then you can actually start to save calories.

SUSAN:
One of the problems I think with grazing and the food we eat on the run, is as you say it tends to be very energy dense and there’s not many fruit and vegetables in it. The big advantage of fruit and vegetables is they clearly are good healthy foods in their own right, but they tend to dilute some of the calories in the meal. And so people do like to have a plate full, as it were, and if you fill that up with fruit and veg you’re going to minimize the calories while your maximizing the volume.

PETER:
Lets look at some of the components, we have eating behaviors so if you can change to eating more healthy foods perhaps your obese patients might stand a better chance. Can we look at fruit and veg, how much fruit and veg, the mixture, and for instance with fruits can you add in processed fruits? And Jimmy Bell said that in fact it’s the people on low incomes who are now getting fat, they're not eating the fruit and veg, how do you square all of this up, what kinds of components of diet would you both suggest?

SUSAN:
Well lets get it clear, obesity is a problem across all social groups, it’s marginally more common in the less advantaged but it’s a big problem right across the board. Eating more fruit and veg probably helps people to control their weight particularly vegetables because they bulk out meals. At the moment people eat fewer fruit and veg than we’d recommend for good health, so rather than setting a prescriptive amount, I tend to just encourage people to eat more. And that can come from not only fresh but frozen and canned. And frozen vegetables: peas, sweet corn, beans etc. are often very cost effective ways for people to have vegetables because there’s no waste and they’re often really competitively priced.

GARY:
And you’ve got to remember the most expensive part of the meal, is perhaps the thing that gives you the greatest energy density which is meat, or the equivalent of that so if you can reduce that and increase cheaper portions such as fruit and vegetables, then you know you’ve energy diluted or you’ve taken energy out of the meal but you’ve still got the same sized meal there.

PETER:
What about dairy produce, can we eat dairy produce or does it have to be low fat or what?

SUSAN:
Well dairy products absolutely can be part of a healthy balanced diet they bring a whole range of important micronutrients. If you’re trying to control calories, it makes sense to choose the low fat varieties and if you’re having things like yogurts and other dairy based desert, to really choose those which are low in sugar as well.

GARY:
And I think one of the things you need to be careful of as well, there’s a little bit of evidence that suggests, consuming low fat dairy in one part of your diet sometimes the fat comes back in, at another part of the diet you take a product which you’ve actually taken the fat from, so you need to be careful about what you choose all the way through.

SUSAN:
Yes, people need to be intelligent about the food that they consume and if you actively choose a low-fat milk, you’ll save a few calories but that doesn’t mean you can then spend them, as it were, on double cream at the weekend.

GARY:
Or increase the portion size!

PETER:
And what you were saying about behavior Gary, because it’s not so much in our behavior to graze on these unprocessed foods is it?

GARY:
Well its difficult, whether we graze or not, what we’ve got to try and get back in our lives is some idea of balance. And I think that’s really difficult to achieve at the present time.

SUSAN:
I think the other thing that I often talk to people, is about trying to get a bit of structure back into their eating habits. For some people, grazing is a kind of fact of life and it’s the only way they can fit everything into a busy day. It’s fine but you need to plan it and you need to think about it a little bit more, so the foods you’re eating on the run, as it were, are adding value to your diet. So I think there are two things for people to concentrate, one is structure, thinking about what you eat, and that leads naturally into second one, which is what we call mindful eating, think about what you’re eating. It’s really easy for some of the less healthy calories to slip in without you really noticing.

GARY:
And there’s lots of tricks you can do for that and again because we tend to eat a snack and we don’t realize it, so you can sit watching the television for example, and all of a sudden you’ve gone through a family packet of crisps. So it’s getting ways to remind yourself of what you’re doing, so some of the things we ask people to do is perhaps until they can change, write down things that they’re eating and recognize the portion size that they’re actually taking.

SUSAN:
Or if you know you’re the kind of person that once you’ve opened the packet you’ll find it hard to stop, either buy the small packets or pre-portion it yourself. Take a small portion in to watch the television and leave the rest firmly in the cupboard in a sealed box. So what I think doctors need to remember is it’s too easy I'm afraid to say to your patient who is over weight, they need to eat less and do more. And what we need to understand is that, that doesn’t work. If it was that easy people would have done that already. So what patients need, is really practical advise about how you can put your good intentions into action.

GARY:
Accepting the fact that it’s difficult for people and people will fall by the wayside, but being allowed to fail is incredibly important.

PETER:
Talking about falling by the wayside, you may have an obese patient who makes good progress, looses weight and then does the yo-yo dieting and gets back to the original body weight in no time flat, how do you avoid that?

SUSAN:
Firstly, weight regain is exaggerated, it happens I don’t want to deny that, but firstly after any diet regimen, what we see is a proportion of people successfully keep the weight off. Secondly those who regain it, often regain it over many years, one review showed on average it took about five years before people were back at their baseline weight, and that means you’ve had five years less of the metabolic disturbance that obesity causes. So we do need to acknowledge weight regain but we shouldn’t over exaggerate it because otherwise we just put people off loosing weight in the first place.

GARY:
And from a doctor’s point of view, even that short period of time of weight loss, is an advantage medically and an advantage to the general practitioner because people come less to the general practitioner over that period of time.

PETER:
Managing satiety, being satisfied that you’ve eaten enough and you don’t want to eat anymore, is that possible?

GARY:
Well I think one of the things we’ve not been very good at is recognizing the effects that when you actually try and reduce your intake, it makes you feel hungry and feeling hungry is horrible. So finding ways to actually combat that if we can, I think is critically important to long-term success of weight loss.

SUSAN:
Feeling hungry can undermine even the most determined dieter, the challenge is how do you manage that? So partly it’s about structured and planned meals, so you know when your next food is going to arrive and you can organize your life around that. There may be some particular foods or ingredients, which have a modest effect on satiety. So high fibre foods for example are probably somewhat more filling, low glycemic index foods may help you to feel fuller for longer. There are some particular fibre sauces, alginates and the like which have a modest effect but I think we’ve got to be realistic, that these are a very minor boost to natural satiety.

GARY:
And the amounts that you’d need to eat of these things to actually get an effect on appetite, is huge. You’ve got to remember when we first started talking about this, your systems actually make you eat, drive to eat, to stop those, requires an awful lot. So Susan mention dietary fibre, to actually get an effect on appetite with dietary fibre even acutely, you need to raise it by sometime in the region of about two to three times the amount we eat at the present time.

PETER:
So it doesn’t look as if there are magic keys, so you would encourage doctors to talk about practical things with their patients and behavioral things as well...

SUSAN:
Practical things and the other thing doctors can do is, help patients to access the support they need. We know doctors are very pressed for time, so what they can do is help people to access other support in the community, whether that’s family and friends or organize groups of people who are in a similar position.
PETER:
Could I ask both of you, to wind up this by giving us your conclusions? Susan, from what we’ve been talking about could you summarize what you make of the things we know about getting fat what doctors need to be doing for their patients?

SUSAN:
We know that weight gain is incredibly common, and unless people really focus on what they’re eating and their physical activity, it is almost inevitable that they will gain weight as they get older. So we need people to focus on it, think hard about what they’re eating, to plan and structure their diets and absolutely to find a way of including physical activity in their lifestyles, its something that needs to be done over time and sustained.

GARY:
And to compliment that, healthcare professionals need to be involved, they need to not be afraid of actually managing people who are over weight and obese, and the advice needs to be practical and it needs to be long-term. Your not going to cure this or treat this over time, people need a lot of support to change any behavior not just food behavior, any sort of behavior.

PETER:
But in summary, this is perhaps one of the most important threats to the health of society of today…

SUSAN:
Absolutely. Obesity underpins so much of the chronic disease that family doctors are spending a huge amount of time treating. And I really want to urge doctors to look into this in more detail because if we tackle obesity as a first-line, then actually we can reduce a whole raft of health risks in one go.
GARY:
And we know changing the way that the general practices engage with over weight and obese people can lead to successful management.

PETER:
That’s all for now but all of you listening can find practice sheets on nutrition, we’re going to supply you with information, and all you have to do is visit the MDFM website. They’re downloadable as PDF files and in lots of different languages. So it remains for me to thank Dr Susan Jebb OBE, from the MRC nutrition unit in Cambridge, and professor Gary Frost from Imperial College. So thank you both of you for all of this amazing insight, I’m certainly a lot more knowledgeable and thank you to our sponsors the Danone Institute for supporting this programe. We’ll be back soon with more from MDFM, so from Gary, Susan and me Peter Goodwin, goodbye!


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