Alfred Deakin Professor David Crawford and Associate Professor Kylie Ball together with Professor Robert Jeffrey from the University of Minnesota, and Professor Johannes Brug, VU University Medical Center, The Netherlands are the proud editors of a new book - Obesity Epidemiology. From Aetiology to Public Health.
The book is an update of the 2005 version and provides an overview of the causes, prevalence and trends, and the health, social and economic consequences of obesity. The latest evidence regarding prevention strategies and the potential of public health initiatives are also covered.
This extract from the book contains the conclusions drawn by the authors:
The case for a preventative approach to the obesity epidemic is compelling. Obesity poses what is arguably one of the most significant threats to population health that we currently face. The data presented in this book highlight just how common obesity has become in children and in adults across the globe, and how it impacts disproportionately on the poor. This epidemic, as described in the first two chapters of this book, now affects more than one in five children and more than one in two adults in many countries in the developed world and as detailed in Chapter 10, obesity is also becoming increasingly common across the developing world. This public health crisis appears to have been steadily worsening since the 1960’s. Over this same fifty-year period the scientific evidence regarding the effects of obesity on health and well-being has also grown. The immediate and long-term physical and psychosocial health effects of obesity on individuals, both direct and indirect, are substantial, and experienced by children as well as adults, as illustrated in Chapters 3-5. The impact on health care resources, described in Chapter 6, is enormous, further underscoring the need to take steps to reverse the obesity epidemic.
Despite the recognition that obesity is a prevalent and serious condition, there remains much to be learnt about the underlying drivers of the epidemic. With gaps in knowledge regarding the specific triggers for the rapid shifts in population eating and physical activity behaviours and obesity, our capacity to develop efficacious and sustainable obesity prevention initiatives is limited. Evidence for population-based approaches to the promotion of physical activity and healthy eating is accumulating, although research in relation to the prevention of unhealthy weight gain from a public health perspective is still in its infancy. The modelling presented in Chapter 15 does suggest however, that from an economic perspective, obesity prevention initiatives are a good investment.
It is clear from the material presented in this book that the obesity epidemic is a complex phenomenon. This complexity exists at a number of levels. As already discussed, the drivers of obesity – both proximal (see Chapter 7) and more distal (Chapters 8 and 9) are complex. While for any particular individual their unhealthy weight gain might be due to poor eating or inadequate activity, from a population perspective there is little doubt that both sides of the energy equation contribute and thus both physical activity and eating behaviours must be tackled – making finding solutions difficult. The underlying influences on our eating and physical activity are also not straightforward, involving a range of personal, social and structural factors that are likely to vary in their relative importance for different populations and for different sub-groups within the same population. In addition, there are powerful global commercial and political interests at stake. Sections of the commercial sector have come to recognise they have contributed to the obesity ‘problem’ and therefore have a role to play as part of the ‘solution’. However such views are not universal and even amongst those companies that have recognised the need for their contribution, change is not always occurring in the way or at the pace required. Debates about whether it is our eating or activity that is more important as a cause of obesity, or whether preventing obesity is a personal or societal responsibility are unhelpful, and can only serve to distract us from acting to address the obesity epidemic.
Although the evidence to inform obesity prevention initiatives is limited, it is accumulating, as documented in Chapters 11-13 and throughout the latter parts of this book. Because of the rising rates globally it is important that governments, non-government agencies, the commercial sector and community groups act now. In doing so, it will be imperative to rigorously evaluate any initiatives aimed at preventing obesity to ensure any investment in preventative action is paying dividends and that there are no unintended harmful consequences. Programs or other initiatives that ignore the available and emerging evidence base, that are rolled out without a strong evaluation component, or that are delivered for only a short time are unlikely to have any meaningful impact on population obesity. The material presented in the final part of this book on potential approaches to obesity prevention will be useful in informing those charged with making decisions about how best to prevent obesity and minimize its health, social and economic impacts.
The framework for tobacco control described in Chapter 16 provides a potential model upon which to base obesity prevention efforts and also serves to remind us that public health approaches can be highly successful. Other chapters in the final part of the book have identified a variety of potentially promising leverage points to tackle obesity. These include influencing parenting practices and the home environment, social marketing approaches, legal, fiscal and regulatory options, and urban planning and transportation policies. In each of these areas the contributing authors have drawn on the existing evidence and built a case as to why obesity prevention efforts should include a focus on each of these intervention points. Adopting such a multi-pronged approach will be essential, but will also be challenging, requiring those concerned with obesity prevention to find common ground and to work closely in partnership with those from a range of other sectors not always traditionally involved with public health.
It may seem obvious but it is important to make the point that because the obesity epidemic has taken at least half a century to develop it will not be reversed quickly – it could well take at least a decade to see any significant reversal of the current trends, even with well-resourced and strategically-focused efforts. This is not simply because of the large numbers affected – it is because we still lack a detailed knowledge of the root causes of the epidemic and because many of the issues that may need to be tackled are complex, some of which may require strong political will – or which may require us, as Schwartz and Brownell have urged (Chapter 25), to be courageous! In considering how and where best to invest to prevent obesity it will be important for us to be courageous and also to be more forward-thinking – to engage in some future-gazing. Few people in the 1960s would have predicted what our lifestyles and our environment would look like now – for example, technologies like mobile phones, the internet, wireless broadband, on-line shopping, on-line social networking and so forth were the stuff of science fiction 50 years ago. We need to ask ourselves what the world will be like and how people will be living their lives in 10 and 20 years time, and take steps now to put strategies in place that will support people to be healthy in a world where obesity risk may be even greater than it is now.