Book Review

The Health Impact of Smoking and Obesity and What to Do about It

N Engl J Med 2007; 357:2525-2526December 13, 2007

Article

The Health Impact of Smoking and Obesity and What to Do about It
By Hans Krueger, Dan Williams, Barbara Kaminsky, and David McLean. 374 pp., illustrated. Toronto, University of Toronto Press, 2007. $65 (cloth); $29.95 (paper). ISBN: 978-0-8020-9200-7 (cloth); 978-0-8020-9441-4 (paper).

Many public health scholars consider the decline in the prevalence of smoking in the United States during the past 50 years to be a signal accomplishment, perhaps second only to reductions in infant and maternal mortality that were achieved earlier in the 20th century. Although the prevalence of smoking in this country has fallen by nearly half since the 1950s, smoking is still considered the leading cause of preventable death in the developed world. In contrast, the prevalence of obesity has more than doubled in the United States during the past three decades and has also risen markedly in other developed countries. Thus, combating obesity by using the approaches that have been so effective in reducing smoking seems to be an obvious choice.

On the basis of their experience in developing the British Columbia Healthy Living Alliance (formed in 2003 and scheduled to reach several important targets by 2010, when the Winter Olympics will be held in Vancouver, British Columbia), Krueger, Williams, Kaminsky, and McLean try to meld reviews of the literature concerning the effects on health of smoking, sedentary behavior, unhealthy diet, and obesity with reviews of clinical and public health interventions that have aimed to reduce these risk factors. The reviews of interventions are subdivided by demographic group (children, adolescents, pregnant women, and the general population), by focus (individual, community, and total population), by mechanism (behavioral modification, modification of the built environment, mass media campaigns, regulatory tactics, taxes and incentives, and combined approaches), and by economic evaluation.

The authors, who are enthusiastic health advocates, are scrupulous in their assessments of the magnitude of risk factors and the effectiveness of intervention. Their discussion of the ongoing disagreements over the impact on health of moderate levels of excess weight (i.e., “overweight”) is one of the most balanced and informed that I have seen. They also review newer evidence that fruit and vegetable consumption may have only a limited effect in reducing the incidence of cancer. Unlike authors who estimate the costs of obesity without estimating the costs of interventions to reduce obesity, Krueger and his colleagues provide detailed empirical information on intervention costs from the British Columbia Healthy Living Alliance.

One expects that the chapters in multiauthored books will have some overlap in content and some stylistic inconsistencies, but in reading this book, I was too often confused when a topic that was initially examined using scholarly prose was later discussed in an almost folksy tone. Nearly a third of the book is taken up by sequentially numbered references and footnotes, which makes it difficult to connect footnotes back to the originating references. Interventions that are clearly effective, those that are clearly ineffective, and those for which the evidence is equivocal are sometimes presented without clear demarcation.

I was surprised that there was virtually no mention of the Diabetes Prevention Program. This well-documented study demonstrated that behavioral interventions in a large, ethnically diverse population could achieve substantial long-term weight loss with concomitant and striking reductions in the incidence of type 2 diabetes.

A more important limitation of the book, however, is the authors' rationale for singling out obesity over poor diet and sedentary behavior in public health campaigns: “The rationale may be finally one of `optics,' or how each risk factor plays out in the popular imagination . . . obesity provides a compelling parallel to tobacco in the minds of the general public.” This view is reflected on the book's cover, which displays an unflattering photograph of a young obese man smoking a cigarette. Together with the book's title, this photo may mislead some into thinking that the book is primarily about biologic interactions in obese smokers. Given their premise, it is puzzling that the authors repeatedly state that obesity is a biologic rather than a behavioral characteristic, that adolescents and young women are vulnerable to the psychosocial impact of negative body image, and that unlike tobacco, food is a necessity. I doubt that portraying obese people negatively in a stereotypical visual context will produce a public health benefit.

David F. Williamson, Ph.D.
Rollins School of Public Health of Emory University, Atlanta, GA 30322