What is driving global obesity trends? Globalization or "modernization"?

BACKGROUND: Worldwide obesity has more than doubled since 1980. Researchers have attributed rising obesity rates to factors related to globalization processes, which are believed to contribute to obesity by flooding low-income country markets with inexpensive but obesogenic foods and diffusing Western-style fast food outlets (dependency/world systems theory). However, alternative explanations include domestic factors such as increases in unhealthy food consumption in response to rising income and higher women's labor force participation as countries develop economically ("modernization" theory). To what extent are processes of globalization driving rising global overweight/obesity rates versus domestic economic and social development processes? This study evaluates the influence of economic globalization versus economic development and associated processes on global weight gain.

RESULTS: Using two-way fixed-effects OLS regression with a panel dataset of mean body weight for 190-countries over a 30-year period (1980-2008), we find that domestic factors associated with "modernization" including increasing GDP per capita, urbanization and women's empowerment were associated with increases in mean BMI over time. There was also evidence of a curvilinear relationship between GDP per capita and BMI: among low income countries, economic growth predicted increases in BMI whereas among high-income countries, higher GDP predicted lower BMI. By contrast, economic globalization (dependency/world systems theory) did not significantly predict increases in mean BMI and cultural globalization had mixed effects. These results were robust to different model specifications, imputation approaches and variable transformations.

DISCUSSION: Global increases in overweight/obesity appear to be driven more by domestic processes including economic development, urbanization and women's empowerment, and are less clearly negatively impacted by external globalization processes suggesting that the harms to health from global trade regimes may be overstated.