Global Evidence on Obesity and Related Outcomes: An Overview of Prevalence, Trends, and Determinants

This study documents prevalence rates, trends in, and determinants of body mass index (BMI), outcomes related to obesity, and proximate inputs into obesity such as caloric intake for panels of countries, categorized by geographical regions and levels of development for the time period 1980–2008. Our estimates inform the nature and scope of obesity on a global scale, and contribute toward an understanding of the drivers of the upward trend in obesity and toward identifying effective public policy responses. The cross-national trends, across countries spanning the spectrum of economic development and geographic regions, suggest that obesity is not a problem limited to the United States and other developed countries, but rather a global concern. With the exception of Sub-Saharan Africa and the group of low-income countries, average BMI levels for all other country groupings (based on geographic regions and level of economic development) had reached the overweight/pre-obese range by 2008. Concurrently, we also observe an increase in glucose levels. We further find that higher caloric intake globally over the past three decades may be a direct driving factor to the increase in BMI. Fixed effects regression analyses reveal that changes in real GDP per capita and labor force participation can partly explain the increase in BMI through their impact on caloric intake and physical inactivity. The commonality in the rising trends in BMI and obesity around the world is suggestive of common underlying causes, although substantial heterogeneity remains, as well as marked differences by gender.