There is rarely consensus among scientists and public policy experts. Nonetheless, an exception to this “rule” is the uncontested reality that obesity rates worldwide have reached unacceptable levels and that if this trend is not reversed, health, economic, and societal consequences will soon be stretched beyond capacity. Among the first areas to experience increasing rates of obesity have been wealthy, industrialized nations. However, not all such nations have experienced similar increases, and understanding these differences might provide valuable information as to how unhealthful obesity trends might be curbed in nations not yet beginning to experience this potential health crisis. To shed light on this critical issue, researchers at the US National Center for Health Statistics (a component of the US CDC) recently compared and contrasted current obesity prevalence rates among residents of Canada and the United States. They also reported changes in these rates over the past 2 decades.

Data sources and definitions Estimates of US obesity rates were drawn from 2 surveys that are part of the NHANES, specifically, NHANES III (1988–1994) and NHANES 2007–2008. These surveys were designed to be representative of all ages of the noninstitutionalized, civilian population and conducted in a way that allowed oversampling of population subgroups (eg African Americans) of particular interest. Estimates of Canadian obesity rates were based on data from the 1986–1992 Canadian Heart Health Survey and cycle 1 (2007–2009) of the Canadian Health Measures Survey, the latter of which is very similar to NHANES in design.