Joining Forces to Tackle Obesity, 21-22 January 2002

 

Transcript : Preventing Obesity Through Physical Activity Strategies

 

Prof. Ken Fox

Department of Exercise and Health Studies, Bristol University

 

DR WILLIAM DIETZ: I’d like to get the programme under way again. Okay, our next speaker, or the next section is on Preventing Obesity Through Physical Activity Strategies. The first talk is on the link between sedentary behaviour and the prevalence of obesity, promoting active lifestyles through physical recreation and active transport. The first speaker is Professor Ken Fox, who’s from the Department of Exercise and Health Sciences at Bristol University. Ken.

KEN FOX: Thanks Bill. Thanks for staying around and hope you got your stretch in. Many thanks to the National Audit Office, in particular Rob Predo, who’s down here somewhere, who’s been on this right from the start and done an excellent job. I think we’ll look back on this report and this conference as being a real landmark session for bringing the problem of this epidemic of obesity to light and I think it’s really been excellent. In particular the way it’s been presented. I’m very sensitive to the fact that obesity is frequently seen as a simple problem of greedy people eating too much all the time. And I think this conference has made it quite clear that it’s a much broader problem than that, it’s equally presented physical inactivity alongside food decisions, it’s equally presented the individual decision making process alongside the critical influence of a toxic, increasingly toxic environment and a culture. So I think that whole package is a very impressive, comprehensive package and I’m glad to hear that the right message is seen to be out there now and let’s hope it’s the start of a new era for us in this field.

 

I also agree with Sue and Tim wholeheartedly about balancing food with physical activity. If we get into the position where we’re stacking one against another I think that will be entirely counterproductive. Having said that, I would like to clarify how important activity is or the problem of inactivity. Because there have been some confusing messages I think come out of the two days. Believe me, and I would quote the recent American College of Sports Medicine stand on exercise and weight management, which came out two months ago. Exercise is important for weight loss. It’ll help weight loss. It’s very important for sustained weight loss, which is part of prevention and it’s also very important for preventing weight loss in the first place. But add to that a huge volume of evidence that now establishes activity as being very important for health and you’ve got the bigger picture there as well. If you’re inactive you are twice as likely to suffer from early disease and death so it really is a critical aspect of health. There we are, this is the problem, graphically presented thanks to Fatboy Slim - it’s off an album cover. Here’s me desperately trying to become a normal sized person, this is already achieving what he’s trying to achieve. But this is what we’re all in danger of some of us more than others, and it really is a problem of adaptation really. This is latest in executive weekends away. But this is really what we’re designed for and we’re in an environment now that really is not suited to those kind of energy bases, we’re good at storing energy from times when food is scarce and we’re designed to use our legs and arms for various reasons for survival. And these kinds of things are disappearing rapidly, this is obviously disappeared already in westernised countries. We even make sport these days easy. There are golf courses in the United States where you’re not allowed to walk around because you walk around too slowly and bung up the works. But to summarise very quickly what’s been said many times. We’re really suffering from the problem of fewer active jobs, greater reliance on motorised transport, huge influx of energy saving devices around the home, at work and in the shopping environment is where we spend most of our time, in those three environments. And this additional real challenge that we manage to provide a haven at home of entertainment and children I suspect are particularly susceptible that wall to wall entertainment which is very seductive and tempts us to stay indoors.

 

And the challenge of course is to counteract all these effects. They’re pervasive and they’re easily affordable, most of these things. So putting it alongside food, alongside activity, we are mismatched with all this modern environment because these was a shortage of food obviously there isn’t now, strong signals to eat, we get hungry and weak signals to stop, we can quite easily stop ourselves. Increased availability clearly, eating’s rewarding, you have to eat at some point and eating is high status. So everything along that side suggests that the temptation is to eat more and that we are programmed to eat when food is around. Activity is the opposite. There’s a weak activity signal, it’s really quite easy to sit down and not worry about it, as most people do it. There are strong signals to stop, particularly if you’re not used to exercise. It’s sweaty, it’s hot, it’s tiring, it can be painful if you do it wrong. So getting people into exercise is a challenge because the signals are against it. There’s reduced availability as we’ve pointed out. Inactivity is rewarding, it’s very nice to come home after a hard day’s work at the computer and then sit down and watch TV. We’re just not occupying our time in a way that should be rewarded by inactivity any more because we’re inactive all day long. Inactivity is a viable alternative at least in the short term, because as I say to it’s dangerous to your health in the long term and it’s high status to be inactive because we like to have two cars in the drive, and a dishwasher and all the rest. So that suggests that we really have a challenge in overcoming inertia and the two together is probably the explanation of why we’re in so much trouble right now with this problem and will be increasingly. I suspect that we’ve not really seen the effect of our children becoming fatter earlier and when that generation filters through then our problem will be even worse.

 

But can physical activity prevent weight gain, while there isn’t a whole host of evidence but the evidence there is convincing, certainly in the right direction. What seems to be the case is there’s evidence that you can attenuate the weight gain, which is typical of people as they grow into middle age. And this is the average weight gain over the years, across these age groups. This is cross sectional data. And what you find is people who are not active obviously are represented here but people who walk actually do better, they don’t put on that amount of weight over the years. People who play golf do well; people who cycle do well until we start cycling slowly presumably. The runner somewhere is there but they all die when they get to 40 so you can ignore them.

 

But there are seriously five or six prospective studies that you could look which are fairly convincing and all point in the right direction that those people who stay active or fit longer really do well to offset that, at least attenuate that weight gain. That actually has produced the epidemic; it’s a gradual slide at the BMI percentiles that’s caused the problem. Not that we’ve suddenly become more fat overnight.

Here’s one example, this is the risk of gaining large amounts, 13 kilograms of weight over a 10-year period. And when you get into these areas people who are low on both occasions, over a 10-year period, seven times the risk in these women of contracting large weight gains, and 6.2 if they decreased. So the relationships are there, everything points in that direction. Certainly those people who are obese seem to sustain it through inactivity because this is hours watched of TV, no it’s not, it’s hours sat down a week among men and women and BMI obese percentage at the side here. So more time sat down, more incidence of obesity, so they’re sustaining their obesity by that behaviour. We have similar data using more objective measures, these little accelerometers that you might hear about. This is Ashley Cooper, a colleague of mine in Angie Page, and what you see is there are differences in movement, because these things pick up our minute by minute movements, so you quantify it and you do see differences across the day and all hours between obese people, that’s these orange ones against the yellow ones. So obese people do sustain their obesity or at least contributes to that through inactivity, lower levels of activity. And you see the big differences are when there’s choice. This is lunchtime and this is after work here. These are where the differences occur. So when choice occurs, none of these people seem to be more active and that’s particularly the case at weekends, here it’s Sunday morning. A huge difference between activity patterns at the weekend for obese versus non-obese subjects. And this is data taken in the work setting among workers.

 

So what should people be doing? And I think this is still a grey area, this is where there is some unsurety if you like about what we should be recommending. But certainly the current recommendations for health stand and they’re saying on both sides of the Atlantic that’s 30 minutes of moderate intensity activity, such as sustained brisk walking on at least five days a week, more is better obviously. Or you can do it in bite-sized chunks which might be more appealing to people who struggle to walk for long periods of time. So that still stands and ACSM recommend 150 minutes a week, which is what this is. As a minimum, 200 would be even better. People who have managed 280, which is an hour a day of walking, total, not all in one go necessarily, actually are quite successful in managing long term weight, from one study at least.

 

So that’s not the whole thing though, really we’re talking about energy expenditure here, so anything that involves weight bearing movement is going to contribute to the whole equation, so this is where your lifestyle activity comes in. So it’s not just about daily walking and cycling, which are really very important for getting the bulk of activity done. The Dutch seem to do it in their daily routines as they cycle everywhere. But more daily weight bearing movement because the formula’s simple, it’s weight times distance. It doesn’t really matter how quickly you get there. So that’s a positive message to give to people, it’s just moving your body about actually burns energy.

 

And if you’re heavier it’s an advantage in that sense. So you can tell obese people that so long as they move around more, it’s all adding points to their activity-energy expenditure score and that’s a very important message. Obviously we’d like people to get into regular exercise or sport involvement, absolutely critical, because you really start to get to levels of vigorous intense activity at that point, which is very beneficial as well for health. The trouble is getting overweight people to that point might be a long process and we shouldn’t just throw them in at the deep end, we should allow them to gradually build up to it.

And then we’ve heard also that another critical variable is not just activity, it’s the amount of time you spend in inactive pursuits such as watching television. And the two aren’t necessarily two ends of a continuum, there are examples of youngsters in particular who are very sedentary who are also very involved in sport and play so the two can go side by side. But it is an important consideration both for adults and for children.

 

And all this is in context of it takes less than two kilograms of weight gain per year for 10 years to move somebody from a perfect weight to a seriously unhealthy weight. So it’s small changes over time that really make the difference and that’s the critical thing, changes in eating patterns, changes in activity patterns over time if sustained will make a contribution. That’s the message you should go away with.

 

So these figures - I’ve just checked them out after some of the figures brought out this morning and I still stand by them - these figures simply work out from the physiology books - if you did your brisk walking for 30 minutes a day throughout the year every day it would make the difference of 12 or 13 pounds and not many people put that amount on over the year. So long-term persistence is the key. Activity requires persistence and patience. Of course if you can get into more vigorous activity, you needn’t do quite the amount of time on it. You can do it in a shorter period of time plus you may get added health benefits as well.

 

So, approaches and I’ll try to flick through some of these because the unfortunate thing of being last on in the conference is much of it’s been said but I think this is important. There are different approaches to use. There’s individual targeting so it’s a kind of, "You’re the person, you have to do something about it approach" and there are several ways of getting across messages here and helping people by awareness raising and the Health Education Authority Campaign which Nick Cavil and company were involved in; it was very important in that because it raised all kinds of issues about exercise being important for health.

 

Persuasion, education and expertise - I’ll come back to these points in a moment, and support. But also environmental restructure is absolutely critical. I’m not going to speak too much about this because we have other speakers who will discuss these issues later. Legislation is another approach where we could actually make it difficult and expensive to use motorised transport for example or we could reward for cycling and walking.

 

I would say that these two have to be developed hand-in-hand. We still have to address the individual decision making process as Sue Jubb said about nutrition and eating but we have to look at the environment because this will fail if the environment continues to be so toxic and unfriendly for physical activity to take place so we have to look at both of them in tandem I’m sure, and this is probably value added if we can get some legislation which helps in that direction.

So the individual approach - I think we shouldn’t write this off. I don’t think that we’ve given this a fair chance yet. There remains a serious lack of knowledge in both professionals and the general public out there about physical activity and what’s really important about it; a lot of misconceptions still so we have to get messages across to doctors, health professionals as well as teachers and as well the general public.

 

You know there is still a lot of mythology out there. If you talk to people about exercise and slimming organisations work constantly on these kinds of issues and see these kinds of excuses or reasons for not exercising; they’re all out there. This is the general public’s belief system about what exercise can do. These are beliefs here, with these: It doesn’t help me lose weight; it will make me look muscley - which puts a lot of women off; it will make me want to eat more. Well, all these are myths and are not backed up by science. "I don’t have the time" is a value statement because we’re not allocating sufficient priority and these are all self-deceptions that were often developed early on in childhood: I’m not the sporty type; I always get left behind and I’m too embarrassed; I won’t go to a health club because I already look fat and I don’t want to show off my body in front of other people. We know from the Allied Dunbar survey that some things help people associate exercise with sport, competitive sport, because when we asked them, "Why don’t you exercise for health?" they tell us the number one reason is, "Because I’m not the sporty type" so we clearly have to do something about what ‘sport’ is and that you can be an exerciser and you can be ‘sporty’ even if you’re not really athletic. So the ways that we present exercise and sport are very critical.

 

These are good things. I’ll very quickly read through those because time’s running on but those are good reasons for taking part in activity that are frequently reported and we have to help people experience those things so that they will become regular participants.

 

You know the individual approach is not going to be simple because particularly people who’re already obese or becoming overweight have often been switched off to exercise and sport over the years and we have to switch them back on again. And we have to get psychological commitment, which is really a whole host of things such as educating, creating expertise, informing people about what’s important about exercise. Do you have to put on a slinky leotard? Do you have to sweat until steam comes out of your ears? Do you have to engage in vigorous activity in sport in order to get some benefits? Well that’s all about expectations and we need to create realistic expectations and good experiences, confidence. All those things are not there currently in many out there in the population.

And we need strategies and support systems to help people out. Good exercise leaders help support the people in their classes, encourage, provide strategies for getting into routines. I exercise every lunchtime because it’s a habit now. We need people to get into habits as well and hopefully at the end of the day all these things will be intrinsically rewarding.

 

And all these things will help individuals get into activity. We need more media campaigns. Not enough is known out there about activity for health. Exercise prescription schemes have grown from grass roots level. They’re successful because people like them and those who run them like them; those who attend them like them. So they must be doing some good. We need other community-based programmes around football clubs, around pubs if necessary. We need to engage fully the commercial weight loss companies. They see a lot of people who need to lose weight. We need to look at workplace programmes as well and we need to make sure that professionals are out there to deliver those programmes at the same time.

 

If we need to target perhaps we should look at middle-aged men because these are at highest risk and there is some evidence that exercise works pretty well for them - perhaps a little better than for women - and this high risk group, before they become deeply entrenched in obesity, it may be a good group to capture and really reverse the process. There’s still hope there because when they become BMI 33 it may be much more difficult to reverse the process.

Very quickly moving onto children. A lot’s been said over the last two days about youngsters primarily because they are becoming obese in larger numbers but also we are setting habits and attitudes for the future so clearly we need to engage youngsters in healthy sport and activity.

 

The licence to be active is reduced and this is my Hillman’s work comparing 1971 with 1990. In order to do what a 7 year old could do in 1971 you have to be 10 years now in terms of going out on your own, cycling, catching a bus into town. The licence is going down. Parents are scared to let their youngsters out. The envelope for freedom is reducing. They’re becoming battery kids. Less walking to school, less opportunity for active play. You’ve seen all these so I won’t go on but really the environment is becoming increasingly unfriendly for youngsters to be active.

 

Some of these we can reverse by safe routes to school; creating more active play areas that are safe and so on but we have to address these critical issues about decision-making in the home. How much help are we giving parents in addressing the issue of youngsters spending too much time in front of the screen? That’s a really difficult issue for parents to deal with. Many parents are relieved by the fact that youngsters are absorbed in a video for three hours because it gives them freedom of time. On the other hand you don’t want it to be a source of a nagging parent and lose the relationship with your youngster so these things need some critical thinking out of how we can best help parents help their youngsters deal with this changing environment. Electronic gadgets are not going to go away so we have to learn how to deal with them and we have to help parents and youngsters learn how to deal with them.

Very quickly - promoting activity through the school. It’s a critical system because 45% of a child’s waking time can be involved or influenced by the school. It’s the last exposure to a captive audience. We get the full socio-economic range in schools. That’s the last time. Those of you who are health promoters realise it’s very difficult to get people back into health promotion programmes once they’ve left the system so that’s why school is really critical. We must get it right there because it’s a last chance in many regards.

 

We know that the school day is absolutely critical. This is accelerometer data as well. Look, here are the peaks of activity [reference to visual aid]. This is walking to school. This is playing out at break-time. This is playing out at lunchtime and this is playing out after school as well. And this is a comparison between overweight children and normal weight children and on all occasions the overweight children are slightly down on the activity of non-overweight children apart from this one which a cynical PhD student of mine said, "It’s the fat kids running to be first in the dinner queue" which I don’t think is a fair analysis at all! And even a greater difference at weekends.

 

So active schools need to think really carefully about not just providing more sports facilities but addressing the whole environment for play as well. We really welcome the input of resource into sport resources but it’s really critical that we use that in the best possible way to create active environments around schools and around sports facilities and that we create curriculum that really switches youngsters on to exercise and sport. As I said earlier many youngsters have been switched off to sport by their early experiences and I think good quality teaching can make a difference there, to create a cultural identity and I think I better stop at that. Okay, thanks very much.