Fat, Fate, and Disease : Why we are losing the war against obesity and chronic disease (32 page)

We have turned more than once to the analogy of global warming. The long-term consequences of the epidemic of obesity and chronic disease are calculated to be of the same magnitude as those of global warming, at least in economic, health, and social terms. Just as with
climate change, these problems require recognition of the science of what is seen as a ‘new’, but is really a rather old, field. In the developing world their solution will necessitate coming to international agreements on courses of action, and in the developed world as well as the developing world this will require a cross-party approach because addressing the problems will take longer than two or three electoral cycles. But in the end the actions have to take place at a local level, and this means having the political will to implement them in the face of possible opposition from competing interests. Greenhouse gas emissions will not be reduced in the UK, for example, unless we can resolve the issues of coal-burning power stations, petrol- and diesel-powered cars and trucks, and the cost of insulating our houses. The government has to engage with the energy industry, with the car and transport industries, and with the building trade. They know the issues, they can see the solutions … but they hesitate.

Awareness is one thing but action is another. If there are behavioural and nutritional aspects to achieving a good start to life, then everyone in a population needs to have enough understanding to make healthy choices. Sadly the quality of nutritional information and nutritional education is generally poor in most countries. Yet the evidence exists that even nutritional education starting in preschool can have considerable long-term benefits. We need educators trained both in nutritional science and in the pedagogy of how to engage children of various ages in the subject, as the approach needed differs greatly between preschool and teenage years. We need a coherent lifelong approach to nutritional education—the Japanese already have such a remarkably effective approach. And that education must be made available to both parents and children. Family eating and food purchase habits can be changed—children are important determinants of what a family eats.

But all this will be meaningless unless there is a more consistent and intelligible method of food labelling to explain its contents. This has been surprisingly controversial, but even well-educated people cannot convert a kilojoule to a calorie, and very often they understand the meaning of the latter but not the former—even though they are measures the same thing, i.e. the energy content of food. Portion sizes are equally confusing, and energy per 100 g means little. In the array of largely meaningless micronutrient ingredients, so often listed as a percentage of recommended daily allowance—who understands what that really means?—the simple information we want to know is lost. In an effort to achieve simplicity, some countries have gone to the other extreme by introducing traffic light labelling systems on food. This does not really help either because we all have a clear idea of what traffic lights mean, and they do not relate to food. Does green mean you can eat as much as you want and red that you should stop eating any of this food? Not really.

And the dieting industry does not help—rather it confuses. Of course dieting products are not really aimed at keeping people healthy, but at the cosmetic market. It thrives off its failures. The biology of weight loss is gradually being understood. It is now clear that in the same way as some people put on weight while others are less sensitive to an obesogenic environment, the ability to lose weight and then to keep the weight off differs markedly between individuals. In general, diet and exercise will lead to beneficial weight loss but it is now apparent that most people will drift back to their set point established by earlier weight gain. It may take a few years but the tendency to return to the unhealthy state will be there—the hormonal and brain drive to eat to the higher set point remains operative for many people. It can be overcome by drugs but most weight loss drugs have side effects. That leaves bariatric surgery, with its own side effects, as the ultimate solution. Not a great choice.

And if we shift our attention from fat to diabetes and heart disease the picture is not very different. By the time we come to the attention
of the physician it is generally too late to do anything but to treat the disease medically. In some cases weight loss will reverse the high blood pressure or reduce the insulin resistance, and certainly exercise and healthy eating are essential parts of treatment, but again, prevention would be better, and in the end, much cheaper. We believe that we are being realistic rather than negative in saying this—we have pointed to many ways in which a difference could be made, albeit over a generation.

As we focus on nutrition we must engage better with the food industry and the supermarket chains from which we buy the majority of our food. So we are asking our governments to engage again with some of the economic giants—with their acknowledged entrenched interests—to see if new accords can be reached. Burgers and fries may not be healthy but vast profits can be made from high volume sales of them at a low cost to the customer. They are cheap and convenient, and—there is no point in being sanctimonious about this—anyone who has looked after small children on a rainy Sunday afternoon in a city knows that it can be easier to keep them quiet by giving them this junk food. This should just be a rare treat rather than a staple, that’s all. We cannot avoid the chemical reality that fat is energy-dense but at the same time contains the flavours that make food enjoyable. And junk food is tasty—humans have evolved to have a taste for foods that help to build up body fat, which are generally sweet or salty.

There are always profits to be made from new technologies. The rate of investment in start-up companies in ‘green-tech’ and in sustainability is a direct outcome of both governments and the private sector recognizing the new realities of climate change and environmental degradation. The environmentally aware consumer may be willing to pay substantial sums to adjust to this new world. We are beginning to see similar trends in the food industry. This industry has long recognized that health claims allow a premium to be placed on the product, so it is not necessary to
reduce the profit margin as sales increase, as is common with other foods. This is most clearly seen with foods made for babies and infants, where the prices charged for simple but safe and clean foods are higher than the ingredients would normally warrant.

But quality control matters—we have seen the tragedy in China, when such control was poor and children were fed milk contaminated with poisonous melamine that unscrupulous farmers and middlemen had added to increase profits. And baby foods should not replace breastfeeding, ideally for six months after birth, but the potential for nutritional supplements to mothers while pregnant or lactating and for better post-weaning foods is obvious. Companies are starting to make research investments in this direction. They should be encouraged, provided that the research is rigorous and any claims made about their health benefits are well evaluated.

All parents want the best for their children, and health-promoting foods seem an obvious market. This market is still perceived as small compared to that of the needs of adults for fast, tasty food, but it will become larger as the economic powerhouses of India and China continue to develop. Indeed they are regions of the greatest need, as health costs are beyond the means of the majority of those who need medical care—so now is the time to act.

Just as with global warming, the issue of promoting a healthy start to life requires taking a longer-term view. Governments are not good at this. A policy to promote health in the population which will not be particularly evident for another generation is not likely to attract votes if an opposition party can offer a tax cut next month. Long-term interventions do not deliver results in the time frame of an electoral cycle, and they also commit the government to long-term resource allocation. But having said this, we should
remember that governments already do this—after all, that is the logic behind state-funded education. It seems to us that we are not thinking clearly enough about the need to invest now for a highly productive next generation in other ways too.

And, at last, some governments are beginning to see this. The UK independent review on obesity by the Foresight group, commissioned by the Department of Health, was published in late 2007. It is a complex document, containing scenarios for possible intervention at various levels in the obesity epidemic—in education, by reviewing the role of industry, through implementation by legislation, and so on. It includes diagrams of Byzantine complexity that look like the innards of a supercomputer and are guaranteed to deter the casual reader. But its conclusions are clear. To quote:

Of 17 different potential governmental policy responses across built, health, fiscal, research, educational, regulatory, social structure and family domains, the only one with a significant impact on obesity in all three scenario contexts explored was to promote/implement a programme of early interventions at birth or in infancy.

Let us hope that this report will not languish on shelves in Whitehall as others have done at the World Health Organization. But as we have seen, there are many reasons why this outcome is a real possibility.

Throughout this book we have been very conscious and concerned about the concept of blame. The naive belief that being fat or developing diabetes or cardiovascular disease is simply a reflection of voluntary lifestyle choices is widespread among the public, many public health officials, and politicians. So blame can easily be attached to ‘gluttonous and slothful’ overweight individuals. This is not a trivial
matter—and indeed one powerful weapon in campaigns to reduce smoking is the stigmatization of the smoker. But we must not stigmatize the obese, particularly the morbidly obese. This is because much of the supposed by blameworthy activity may not be under their voluntary control, or at least may not be easy to control. There are powerful biological drivers that make weight loss very difficult to achieve and to sustain. Secondly, stigmatization creates stress, and this itself can lead to greater weight gain as rising stress hormone levels can induce both more eating and greater fat deposition.

But the blame issue runs much deeper. It impacts on political ideology and policy. If it’s ‘all your own fault’, why should the State remedy it for you? Many from the more libertarian part of the political spectrum would take the view that the State should not have a role in matters of personal choice. That is why political parties in countries like New Zealand and the United Kingdom have found it difficult to venture too far towards trying to control what people eat.

The blame game is extended to the food industry, which is sometimes vilified indiscriminately for its part in the obesity epidemic, and for having nothing but the profit motive on its agenda, regardless of the cost to human health. No doubt there need to be tight controls on what the industry markets and how it advertises its wares. Most of us like to feel, however, that we can choose what to eat, so portion size control and clear labelling are needed to help us consider the consequences of our choice. But from what we can see, much of the food industry is willing to move in this direction—after all, it basically wants to keep selling food and will not be slow to pick up a change in public demand and taste.

The cynics will say that the food industry will go with its customers some way down this path, saying the right things to reassure them about its best intentions, but only so far. Some of the leaders of public health, such as Margaret Chan of the World Health Organization, now argue that we have to test the industry’s resolve here—to offer to engage with them in a joint initiative to
promote health and wealth across the world. If they do not step up to the plate (in more senses than one) they will only have themselves to blame. This is a better use of the blame tactic.

Parents are no longer able to provide the necessary knowledge to the next generation about healthy eating. Thus, we contend that the State has a greater responsibility than is generally recognized. There is no doubt that the focus on blame has inhibited progress—it is easier to blame the individual than to tackle the problem. And in our work we have become very concerned about how to focus on promoting healthy development without giving parents a sense of guilt. We know that this is a real challenge—it frequently crops up in questions in the public lectures which we give. ‘Oh, so it’s all our fault is it?’ parents exclaim, often with some anger. This is wrong because we are dealing with the normal processes of plasticity—it would be the equivalent of saying you should blame your parents for teaching you your first language.

We evolved to have our biology influenced by that of our parents—unlike some animals that hardly have parent-offspring relationships. Just as it is inevitable that you will learn to speak their language if you live with them as a child, it is not their fault if you are the first-born or if you were born smaller because your mother is only 155 cm tall. In Japan is it women’s fault that they have reduced their weight gain in pregnancy? No, it is driven by societal attitudes to body shape and misleading advice from their obstetricians. We need to get beyond this superficial approach, which can be dangerous. We cannot allow this new biology to be interpreted in such a way as to give parents—and women in particular—a sense of guilt. If we do, new scientific advances will be overlooked and future generations will not reap the benefit of what we now know.

In any event, is it anyone’s fault that they live in the modern energy-dense world, surrounded by fast food and sedentary leisure pursuits? Our biology is designed to make the most of it, even if it does have the unintended effect of inducing obesity and increased disease risk.

The new research we have described is opening up exciting possibilities, but also new ethical dilemmas. We already know from our work with children that specific epigenetic changes at birth predict the level of body fat and the degree of vascular injury nine years later. And a large body of experimental data in animals confirms that this biology is important. Further factors which are known to play a role in influencing the risk for the child, such as maternal smoking, obesity, age, diet, and whether a child is first-born or not all influence these epigenetic changes. The power of this technique is manifest from the sheer strength of the association. For some specific parts of the epigenetic profile, the preliminary data suggest that measurements at birth which tell us about the prenatal experience—including the effect of the mother’s diet in pregnancy—can account for a considerable proportion of the variation in fatness in the children many years later. Not only are the amounts of fat that we are talking about large—differences of several kilograms of fat between children—but the predictive nature of the epigenetic mark is stronger than any purely genetic effect and explains more of the influence on a child’s body composition than anything else ever reported.