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STANDING COMMITTEE ON HEALTH AND AGEING
06/11/2008
Obesity in Australia

CHAIR —I welcome representatives of the Telethon Institute for Child Health Research. Although the committee does not require you to speak under oath, you should understand that these hearings are formal proceedings of the Commonwealth parliament. Giving false or misleading evidence is a serious matter and may be regarded as a contempt of parliament. On that note, I will ask if you would like to make a brief introductory statement before we proceed to questions.

Dr Lawrence  —Thanks very much for the opportunity to be here today. We would like to send apologies from Fiona Stanley, who is unfortunately unable to be present today. The reason we wanted to make a submission to the inquiry is that we felt that a lot of the recommendations that are being put forward in the many submissions you have received are not really backed by a great deal of evidence—that is, they have never really been shown to be effective, either in Australia or anywhere else, in preventing obesity or in treating obesity.

We want to offer our suggestions for how you might be able to move forward to develop the evidence base so that in future we can proceed with programs and policies with a greater deal of assurance on their effect. The problem of obesity is much more complex and less well understood than many people seem to believe. There is very strong evidence to describe the increasing proportions of children and adults who have problems with overweight or obesity.

We have good knowledge of the health consequences of obesity, but we have less well developed knowledge of what exactly causes people to become overweight or obese and we certainly do not seem to have very good evidence to support any of the recommendations that are being put forward as having been effective, in other jurisdictions or here, for preventing or treating obesity.

As one example, it is commonly believed that to lose weight you should eat less and exercise more; that if we consume less energy than we expend, weight will be lost, whereas if we eat more, weight will be gained. But this ignores the fact that the body has homeostatic regulation and it can control the amount of energy that is consumed. Sixty-five to 75 per cent of the body’s energy expenditure is the basic metabolism that happens whether we do any activity or not.

If we cut down on the amount of food that we take in, the body can adjust the basal metabolism to reduce our energy expenditure. That is one reason why people who take on calorie-controlled diets often find that there is some initial weight loss that then tapers out over time. On the other side, if we increase our level of physical activity, the body can also respond to that by stimulating appetite, but also reducing the basal energy after we have done our exercise, so you could become more tired afterwards. So it is more complex than just eating less and exercising more.

CHAIR —It sounds simple, though, to eat less and exercise more.

Dr Lawrence —If only it were the case.

Ms HALL —It always works for me. I eat less, exercise more and I lose weight.

Dr Lawrence —We think that further research is needed to understand the genetic and other influences that influence individual metabolism that might explain why two people who have the same lifestyle and the same diets have very different weight outcomes. If we can better understand the factors that underpin and cause obesity, it will be possible to develop better interventions. We understand the urgency in responding to the obesity problem that confronts our nation. We realise that policy responses often have to be developed, even if the evidence base is limited or incomplete, so what we want to recommend to the committee is that whatever strategies or recommendations are implemented should be developed as trials first and evaluated rigorously and methodically so that we can develop our understanding of what works, what does not work and what is the most economical way of dealing with the problems, and allow our information to increase over a period of time.

There have been many ideas that have been put forward in submissions to the inquiry. Most of these, we believe, are amenable to proper testing. There are interventions around workplaces or schools that could be subjected to randomised control trials, for example. Other interventions, such as regulation of food marketing or traffic light labelling of foods, might require cluster trials—that is, they could be conducted in selected trial communities, with comparison communities available to provide an estimation of effect so that the effective undertaking of these programs can be understood. Also, maybe you could implement different programs in different states or territories.

If multiple recommendations are pursued, we believe it is important that they be developed and trialled systematically, with some form of national coordination to ensure that, at the end of a period of time, it would be possible to take the evidence from all those trials and amalgamate it in such a way that we can say, ‘Which of the things that have been done was most effective? Which of the things that have been done could be modified in some way to make them more effective? Which aren’t a very good investment?’ so that we can then go on to justify a nationwide rollout of a program because we have got the evidence to say, ‘This is a worthwhile call on the public purse.’

CHAIR —I will start off with the very interesting point about metabolism, which is, I suppose, what Jill and I have been pointing out throughout this entire inquiry. We have heard about diets and food intake, exercise et cetera. It sounds very easy: you exercise more, less intake, therefore you should lose weight. But we know it is not quite that simple. I was very interested to hear your views on metabolism and how we still do not know enough about it.

One of the things that is interesting is that, if you get one person who consumes 1,500 calories a day and another person who consumes exactly the same number of calories and the same foods, we may have a disparity in terms of who loses weight and who does not. Eventually, though, food intake plays a big role, even without exercise. Would I be right in saying that? If someone were to cut down half of their calories, surely they would lose some sort of weight.

Dr Lawrence —I think that genetic factors are a big reason why some people are slimmer than others for the same amount of dietary intake and the same level of physical activity.

Ms HALL —Can I follow on, Steve, with what you are asking?

CHAIR —Yes.

Ms HALL —I agree with you that two people can eat the same number of calories and have different weight gains but, no matter what your genetic make-up is, if you eat less, you lose weight. I think that that is scientifically proven. There is significant evidence out there to say that it does not explain the other differences that you have identified, but there is evidence out there that if you eat less, you exercise more, you lose weight.

Dr Lawrence —I wish it were that easy. There have been so many tests of different diets. There are a lot of people who are really motivated to lose weight and who feel very bad about being overweight and it is something that is becoming increasingly stigmatised.

Ms HALL —I really need to get this clear: you are saying—

Dr Lawrence —A lot of people do try but fail to lose weight, because the body can really fight to maintain its weight. The body can make big changes to the basic metabolism that you cannot consciously control that can undermine your efforts.

Ms HALL —I want to get something clear. I am hearing what you are saying. You are saying that, if you eat less and exercise more, everyone will not lose weight. Is that what you are saying?

Dr Lawrence —No, I am not saying that at all.

Ms HALL —I want you to clarify that for me.

Dr Lawrence —Let me give an example. Say someone takes up an extra set of physical exercise activities and, as a result of that, maybe their appetite will be stimulated, and if they eat foods as a result of that that are particularly fattening for them—maybe high in sugar or starch or whatever—they can actually gain weight while increasing their level of physical activity.

Ms HALL —That has clarified it. But if they maintain the same food intake or reduce it, then they are going to lose weight?

Mr Mitrou —Not only that. Obviously people can starve to death.

Ms HALL —Yes.

Mr Mitrou —You have seen what happens in a prisoner of war camp or to people in a famine or something like that. Obviously they can starve to death. But everybody is different. Their genetic make-up is different and their genetic history is different in terms of how fat is stored in the body and so forth.

Ms HALL —I agree with you.

Mr Mitrou —Some science has shown that the body tends to defend fat. People can diet and they lose a lot of muscle mass, but the body has defended the fat, so people can go on a diet and they can end up losing muscle mass but not losing the fat. Muscle weighs more than fat. They lose weight. They say, ‘Look, I’ve lost weight.’ But it is not necessarily a healthy weight loss. There are a lot of issues around this that are not just as simple as, ‘Look, I’ve lost weight. I’ve been on a diet. I’ve lost weight. I’ve been out for an hour’s walk every day and I am eating 30 per cent less calories and I am losing weight.’ It does not necessarily mean it is a healthy weight loss. So we are looking at a way that people can continue about their normal lives. It is not nice to feel hungry. It is not nice to feel like, ‘I’m starving. I really wish I could eat something, but if I do I think I’m going to put on weight.’ It should not be like that. It should be almost a lifestyle where you can feel normal and feel sated and not be piling on adipose tissue. That is the ideal.

CHAIR —So you would be advocating a complete lifestyle change more so than people going on crash diets and/or exercising vigorously. People my age put on weight very slowly over a period of time, so I suppose when we want to lose it, we lose it the same way. It takes time.

Mr Mitrou —It is well known that crash diets and those sorts of fad type things are not healthy for people. Much research over the years has shown that, although people can lose substantial amounts of weight and get trim, a year or two or three later often they have put it all back on. That is not the solution that we are looking for and we think that running with this trial methodology might get to the bottom of it. We have sat through the previous submissions today. We have read all the submissions to the committee and the transcripts before coming here.

If we want to get to the bottom of this. We are worried that things are going to be implemented without sufficient evidence to back them up. A couple of things can happen: you can spend a lot of money implementing an intervention and it can work as hoped; after the follow-up period you can find that there has been no change; or, the worst outcome, after the follow-up period you find that harm has been done—as in, in this case, there is more obesity, greater levels of obesity, more people are obese, people are weighing more et cetera. We are really just trying to ensure a methodology that does not allow that level of chance to exist in the rollout of programs designed to prevent obesity.

CHAIR —So you want evidence based programs where the research has been done and you see any benefits and the long-term effects.

Mr Mitrou —That is correct.

Mr COULTON —I am so glad you fellows are here because, as we are getting to the pointy end of this inquiry, that is something that I think about a lot. I am new to this game and the last thing we need is to bring in something that is going to be expensive to the community and inconvenient to the community, without having any great effect. That is something as a committee we will have to deal with in the coming months.

You are right. There is nothing fair about body shape and weight. In my own family, with my own three children, they were all fed the same food when they grew up and they are all different shapes. One of them now gets up at five o’clock every morning with a drill sergeant chasing them around a park for an hour before they go to work every day to maintain a body shape that someone else does not have to work at. So I understand all that.

It is one thing to highlight the problem. Do you have a recommendation that you would like to give us as to how we might go about this, given the complexity of the issue? We have dealt with it right through from childhood to the effects in senior years and the cost on health and all those sorts of things. If you have read all the submissions you are probably in front of some of us at the moment. Have you got a recommendation to this committee as to a way forward from this point?

Dr Lawrence —To be honest with you, having read all that we have read over the period of time, I do not know what the simple answer to the problem is, what will definitely work. There are a lot of good ideas that have been put forward that you look at and think, ‘Well, that sounds logical. That sounds like it’s got a good chance.’ But then sometimes you find that it sounded good at first, but once you dig into it a bit more it is not that easy.

So the recommendation we really want to put forward is: acknowledge that this is an urgent problem that needs to be solved. We all appreciate that. But also acknowledge that we are not certain that these recommendations are going to work, so why don’t we test them properly? And if they do work, that will be great. Then we can fund them and go forward and say, ‘This is something we can do nationally. It is possibly something we could take internationally.’ There may be even options for commercialising new things that could be positive for our economy.

But if we do not do that, if we just go ahead and say, ‘These are the five things’ or ‘the 21 things that we think we should do’—the National Preventative Health Task Force has just put out their report saying, ‘Let’s do these 21 things’—if we just do them and after a period of time we find, ‘Well, there’s been a little bit of change, but what actually did it?’, are we going to be any better off than we are at the moment? As an example, let us consider something that was talked about earlier this morning, the ban on food marketing to children. We know that in the couple of jurisdictions where this has been tried—Sweden, Norway, Quebec in Canada—it has not made a big difference. In fact, in Sweden and Norway it looks as if childhood obesity is continuing to increase after the bans have come in. On the surface of it, you think, ‘Well, this ban is really going to help,’ but in actuality, did it help? Not until we properly try it and do a proper evaluation and say, ‘What did happen as a result of that? What choices did people make?’ can we really understand how we can do something that definitely will help.

Mr Mitrou —And there are other interesting occurrences around the world. You raised the example of Finland.

Dr Lawrence —That is right.

Mr Mitrou —And the North Karelia study and the reduction in cardiovascular disease from that intervention, and it was sort of mirrored by a secular trend in reduction of cardiovascular disease across Finland. But when you look at the obesity rates in Finland—we just looked at them recently—they are just a little bit higher than in Australia. If you look into the data a bit more closely, you find that not all is as it seems. There has been a fall in Australia and around the world in cardiovascular mortality but seemingly a rise in morbidity, or the actual prevalence of heart disease.

Dr Lawrence —Yes, the incidence of disease.

Mr Mitrou —This has occurred over the last 30 to 35 years, and I know this is an ecological observation, but in the last 30 to 35 years there have been a lot of public health messages out there about what to eat and doing more exercise, but it seems that the problem of obesity and, if not death from heart disease certainly the occurrence of it, has been rising, and so we are wondering what is going on here. It seems like a bit of a natural experiment occurring on, essentially, the Western population. We are trying to get to the bottom of it through a means that will give us some direction and we think this kind of trial methodology can help, because what we are worried about is the tragedy of a large-scale national rollout of a program that ends up causing harm and we think the trial methodology can prevent that from happening, because it will give you a signal as to what is working, what is not having an effect and what is causing a negative effect before you roll something out.

CHAIR —Having read the submissions, is there anything there that concerns you that may be rolled out that will have this effect? Is there anything you have seen in the submissions?

Mr Mitrou —The previous fellow mentioned the success of the road safety model and the success of the tobacco model, for example. If we think of those, if we think about the reduction in tobacco use, tobacco smoking, over the last 30 or 40 years—and remember tobacco use is highly correlated with cardiovascular disease and heart attack as well—we have seen this dramatic ramping down of tobacco use, from over 50, 60 per cent 40 years ago down to 20-odd per cent or whatever it may be. There are various measures around the place, but it is reasonably low. There is a big difference. We knew that tobacco caused lung cancer. We do not necessarily know exactly what causes obesity. You can have a much better chance of success with an intervention if you know that one thing is causing another, if you know that there is this causal pathway, here it is, it is not in debate.

CHAIR —But we know what is causing obesity. We know it is too much food and leading a lifestyle that is not active. If you look at other generations—

Mr Mitrou —What we are saying is, is that what it is?

CHAIR —If you look at other generations, if you go back 20, 30, 40, 50 years, people were more active and there was less intake of food. I think one thing that everyone would agree with is that the lifestyle we lead is what is causing our overweightness when you compare us with a few generations back.

Dr Lawrence —There are so many paradoxes. We think that we lead much more sedentary lives these days, but if you look at the figures, there is a lot less obesity in people who are managers and administrators who you might think sit at a desk. Manual labourers, unfortunately, have a much higher rate of obesity and you would think they would be out there doing a lot of physical activity. Why is that? It is obviously being offset by something else. The problem is then in the diet or whatever, and it is unfortunately something that we cannot break down to a simple message, ‘Less fat, more exercise.’

It seems to be something that we need to have moderation, we need to have balance. You cannot go to a zero fat diet. If we look back at the original dietary evidence that was brought out in respect of heart disease, the message originally was, ‘Less saturated fat, more polyunsaturated fat,’ and the monounsaturated fats, well, they did not seem to have an impact either way. We have taken that to say, ‘Just cut down on fat,’ and as a result we are eating more sugars and starches. Is that necessarily healthy?

Mr BRIGGS —In your submission you talk about the amount of research you have done on child health and development over the last 15 years and in particular the last two years. It is fair to say you have looked at a fair bit of evidence?

Dr Lawrence —We have looked at a lot of evidence, yes.

Mr BRIGGS —In that experience of looking at that evidence, accepting that there is a problem with obesity, are there also problems with malnutrition or underweight with young people?

Dr Lawrence —Much less than was the case in past generations. That is one thing that we can be happy about as a country. There are still areas where it is a concern.

Mr BRIGGS —But less overweight issues?

Dr Lawrence —Much less than there was, and there is certainly less incidence of diseases that are linked to particular nutritional deficiencies.

Mr BRIGGS —Body image?

Dr Lawrence —That is an ongoing issue of concern, and there is a risk that the more we concentrate on obesity, the more people we might push into eating disorders.

Mr BRIGGS —Some people have a moral panic about obesity, making everyone feel like they are fat and you have to do something about it, and so forth. There are very good reasons why you should lose weight at times. Do you think that impacts on perceptions amongst particularly young impressionable girls?

Dr Lawrence —For some people. If a person is prone to have problems with self-esteem or some sort of mental health problem perhaps, then they are going to be more susceptible to that sort of message, and we do have to be careful. If we are pushing a one-sided message, there is a risk of people taking it to extremes. The same thing could also be a risk with the issue of exercise. We have increased the exercise requirements for children from 20 minutes, three times a week, to 30 minutes a day, to 60 minutes a day. People are saying, ‘Should it be 90 minutes a day?’ Will we get to a stage where some kids are at risk of overexercising, even when they are perhaps not well or the conditions are too hot or whatever? You have to have balance in these things, so the message has to be tailored a little bit to respect the fact that for some people there is going to be an issue that they are going to think they need to be thinner and thinner and that is obviously as dangerous as being grossly overweight.

Mr Mitrou —There is another semi-related issue here, and it is something that I have not seen come up today. It may have been in one of the submissions. There is the issue of fatness and fitness. Just because someone is carrying a few extra pounds does not mean that they are unfit. I am not talking necessarily about people who are highly muscular, such as rugby players, football players and weightlifters et cetera, but people who are literally carrying extra adipose tissue, a little bit of a spare tyre and that sort of thing, but they can still be quite aerobically fit. Then you get other people who are literally straight up and down who could not run around the block without expiring. Some people, try as they might, are never going to look like Twiggy, but they might be fitter than Twiggy. They might have a lower risk of cardiovascular disease than someone who is very thin—someone who is thin and smokes, for example. So we have to be careful where we go with the whole body image thing.

Mr BRIGGS —In that respect, is the body mass index the right index that should be pushed as well?

Mr Mitrou —I think the body mass index is a crude tool. It can work reasonably at the population level with some assumptions, because sometimes when you are collecting data—and we have an expertise in that area—and you are in a household or what have you and you are collecting population-level data, the easiest thing to do is the height and weight and out you go. A waist circumference measurement is more instructive, but there are issues there as well. The best thing to have is a DEXA scan but that is expensive and cumbersome. The BMI is imperfect—I do not like using it—but sometimes it is a case of ‘in the absence of anything else’. You would not tend to use it at an individual level—that would be just part of your suite of diagnostic tools—but as a broad population measure, sometimes it is all you have got. I do not like it personally.

Mr BRIGGS —Thank you.

Ms HALL —Could you tell us a little bit about the funding base for the Telethon Institute for Child Health Research.

Dr Lawrence —The Institute for Child Health Research is a privately owned organisation.

Ms HALL —Privately owned?

Dr Lawrence —Affiliated with a number of universities: the University of Western Australia, Curtin University where I have an appointment, for example. The funding mix is a combination of funds, one from nationally and internationally competitive grants such as the NHMRC or the ARC, and contract work that we do for governments and other organisations. We also have some funding from charity, such as the annual telethon.

Ms HALL —What is your background?

Dr Lawrence —I am personally a statistician. My particular expertise is in the collection and analysis of data.

Ms HALL —And Mr Mitrou?

Mr Mitrou —I was originally an economist and worked for many years at the Australian Bureau of Statistics in large-scale population surveys and statistical analysis. I have been working for the last eight years with the Telethon Institute, initially on an outposting from the ABS and subsequently as an employee for the Telethon Institute in an analytic role.

Dr Lawrence —I have to say that we are not suggesting that there should be more research because we want the institute to be funded to do more research. There are plenty of organisations that could do the work. We are not here trying to raise money for the institute.

Ms HALL —Your background is in the health science area?

Dr Lawrence —I am not a registered medical practitioner but I have done work in mental health and Aboriginal health.

Ms HALL —What are your qualifications in those areas?

Dr Lawrence —I have a PhD in public health and psychiatry and behavioural science.

Ms HALL —And you, Mr Mitrou?

Mr Mitrou —I have an economics background. I have an economics degree and worked in statistics in the ABS for many years in the practical application of statistics and subsequently in an analytic role at the institute, working on Aboriginal health data in the last few years and general child health data in Australia and Western Australia.

Ms HALL —With an emphasis on the statistical analysis. Is that correct with both of you?

Mr Mitrou —And writing reports that come out of that analysis. We do not just crunch the numbers.

Ms HALL —Of course.

Mr Mitrou —We then interpret them for people to use. We write papers for peer review journals and reports and so forth.

Ms HALL —Thank you very much.

Mr BRIGGS —And Professor Stanley is involved in your work as well?

Mr Mitrou —Yes, she is. She is our boss, effectively, and we work closely with her.

Dr Lawrence —She was an integral part of our submission. We consulted with her prior to coming here today.

Mr BRIGGS —Thank you.

CHAIR —There being no further questions, thank you very much for your submission. We will make sure that we stay in touch and send you out the recommendations when we do come up with some towards the early part of next year.

Mr Mitrou —Thank you very much for the opportunity, and if there is anything that was not clear today and you need extra information, do not hesitate to get in touch with us.

CHAIR —Thank you.

[11.20 am]