Global Obesity and Interventions

By Judie Bizzozero, Senior Editor

A four-part series focusing on global obesity was published in The Lancet on Aug. 26, just weeks ahead of the first high-level meeting of the UN General Assembly on noncommunicable diseases, which was slated to discuss the global rise of obesity.

The articles took an in-depth look at the drivers of the obesity epidemic; obesity trends in the United States and United Kingdom, including their impact on prevalence of diseases and health-care spending; and interventions needed to halt and reverse the epidemic. Also included in the series was discussion of a new Web-based bodyweight simulation model that illustrates metabolic adaptations that occur with decreasing bodyweight.

The series found that, in low-income countries, obesity tends to affect middle-aged adults, especially women from wealthy, urban environments. In high-income countries, obesity affects men and women of all ages; however, it is disproportionately greater in disadvantaged groups.

Experts have concluded that the global obesity epidemic is fueled by changes in the global food system, which is producing more processed and affordable food than ever before, and by the market economy, which stimulates overconsumption. Additionally, overeating is often associated with increasingly sedentary lifestyles.

Generating the most media coverage was the finding that global obesity rates have doubled in the last 30 years, with an estimated 1.46 billion adults and 170 million children classified as overweight or obese worldwide in 2008. Experts predict that, without successful interventions, another 65 million Americans and 11 million more adults in the United Kingdom will be obese or overweight by 2030.

The authors of this paper, Health and economic burden of the projected obesity trends in the USA and the UK," contend governments need to take an active role in sustained obesity interventions because health-care systems will be overwhelmed to a breaking point" to treat the millions more cases of cancer, diabetes, heart disease and stroke directly linked to obesity.

Lead author Dr. Y. Claire Wang, Sc.D., Columbia University, Mailman School of Public Health, New York, warns that obesity will replace tobacco as the single most-preventable cause of chronic noncommunicable diseases. She estimates medical costs associated with treating obesity-related diseases in the United States alone will skyrocket to between $38 billion and $66 billion annually.

Taking no action would have the catastrophic consequences described in our study, but a population level decrease in BMI by 1% would avoid as many as 2.4 million cases of diabetes, 1.7 million cases of heart disease and stroke, and up to 127,000 cases of cancer in the U.S. alone," Wang says.

A second paper, Changing the future of obesity: science, policy, and action," concludes that sustained prevention efforts have barely begun at the international level, and it identifies several cost-effective policies that governments should prioritize for implementation. Specifically, the authors conclude that the federal government should do more to combat rising obesity rates in the United States, including taxing sugar-sweetened beverages and restricting certain food and beverage ads marketed to children.

Governments have largely abdicated the responsibility for addressing obesity to individuals, the private sector and non-governmental organizations," the authors say. Yet the obesity epidemic will not be reversed without government leadership, regulation and investment in programs, monitoring and research."

A third paper, Quantification of the effect of energy imbalance on bodyweight," examines metabolism and realistic methods for losing weight. Researchers from the U.S. National Institutes of Health created a dynamic mathematical modeling approach to human metabolism that integrates their knowledge about how the human body responds to changes in diet and physical activity. The researchers assert the resulting computer program accounts for initial body composition and changes in metabolism as individuals diet.

A fourth paper, The global obesity pandemic: shaped by global drivers and local environments," notes that simultaneous increases in obesity in almost all countries seem to be driven mainly by changes in the global food system, which is producing more processed, affordable and effectively marketed food than ever before. That this passive overconsumption of energy leads to obesity is a predictable outcome of market economies predicated on consumption-based growth. The global food system drivers interact with local environmental factors to create a wide variation in obesity prevalence between populations.

The authors note some governments are making promising moves to curb obesity, but also called for more interventions. The authors noted that, although the 2004 World Health Organization global strategy on diet, physical activity and health provides an excellent overall guide for societal action, with few exceptions, governments have made slow progress implementing the strategies. On the other hand, they note, food and media industries have moved rapidly by making various national and international pledges, including self-regulatory codes of practice.

For example, in the mid to late 2000s, England developed a series of initiatives, including a Foresight Report" that examines ways to positively change obesity levels, a cross-government strategy for obesity, restrictions on unhealthy food marketing to children, and a yearly national child-measurement program. Other countries, including the United States, have made substantial steps in national monitoring programs, restricting marketing to children and improving school food. For example, the U.S. White House Task Force on Childhood Obesity holds much promise to bring about change because of its high-level political commitment. The authors also note that international leadership from the Untied Nations and its agencies, as well as more national leadership from other countries, will be essential to solve the global obesity epidemic.