Stemming the Global Obesity Epidemic: What Can We Learn from Data about Social and Economic Trends?

Roland Sturm, Senior Economist, RAND, Santa Monica, CA, USA

Although the policy debate is only slowly moving away from the focus on individual-level psychological and social factors, the research community has largely recognized that changes in dietary and physical activity patterns are driven by changes in the environment and by the incentives that people face. Many factors have been suggested as causes of the "obesity epidemic" - automobiles, television, fast food, computer use, vending machines, suburban housing developments, portion sizes, female labor force participation, and countless others. Putting a multitude of isolated data points into a coherent picture, is a challenging, but necessary, task to assess whether proposed solutions are promising or likely to lead us down a blind alley. Conventional wisdom is an unreliable guide and, as we will see in this presentation, some widely held beliefs are incorrect.

Can we distinguish important and less important behavioral changes and relate them to environmental incentives? People face trade-offs in allocating their scarce resources of time and money to best achieve their goals, including health. Studying what people are doing with their time and their money is a good start towards understanding how economic incentives have altered energy intake and energy expenditure in a way that led to weight gain. I will discuss findings from recent and ongoing projects that study the role of local food prices, business environments, and urban design in several countries.

A challenging task for policy will be finding the right levers. A seeming paradox that emerges from research is that local disparities, such as variations in dietary patterns and obesity rates between neighbourhoods, will require regional or national action, while secular trends observed at a global and national scale will be countered more effectively by local changes.