Obesity Epidemiology

SOCIAL DETERMINANTS OF OBESITY 343Obesity is a condition whose primary and most proximate determinants (diet and physicalactivity) are not elusive; however, we are increasingly learning that to promote a shiftin population distribution of obesity requires attention to the full range of social factorsthat impact dietary and physical activity practices. Indeed, embedded within the socialcontext are myriad determinants of obesity; these factors are tightly interrelated withthe condition at multiple levels. It is well known, for example, that dietary choices andopportunities for physical activity are heavily patterned by socioeconomic resources.Chronic exposure to psychosocial stress may increase the likelihood of “comfort eating.”Depression might diminish one’s interest in a physical activity regimen. Together, a rangeof social determinants are implicated in the epidemic rates of obesity both in the UnitedStates and abroad. However, research attention to the social determinants of obesity is inits infancy; it is critical to both identify determinants with putative relations to obesity,while continuing to investigate their assessment better.The purpose of this chapter is to review the empirical evidence, in a range of populations,detailing associations between selected social determinants and obesity. Secondaryaims include discussing measurement strategies for the various social determinantsreviewed and introducing methodological approaches that might be useful when conductingsocial determinants research. We primarily focus on obesity outcomes, although wewill discuss associations that are mediated by diet or physical activity when appropriate.There are a wide range of potential constructs that might potentially fall under theumbrella of social determinants research. In selecting the social determinants reviewedhere, we have attempted to identify factors for which there is sufficient evidence to drawmeaningful conclusions and for which there is some consensus regarding appropriatemeasurement strategies. As the literature in this area is extensive, our discussion is limitedto (a) studies examining obesity outcomes (including body mass index [BMI] andweight data) rather than dietary and/or physical activity end points; (b) general, nonclinical,and adult populations; and (c) data collected outside of intervention trials.Sociodemographic CharacteristicsSociodemographic variation in obesity is considerable. Individuals generally gain weightas they age (with the most substantial weight gains occurring during middle age). Over thelast quarter-century, obesity prevalence among those aged 65 to 74 has been particularlystriking; rates of obesity in this age group have doubled from 1976-1980 to 1999-2002.In nearly all industrialized nations, women are found to have the highest levels of obesity.In the United States, women’s higher rates of obesity have been shown nearly consistentlyfor the past 40 years, as demonstrated in the nationally representative National Health andNutrition Examination Survey (NHANES) studies (see Chapter 2). Sociocultural factorsamong some populations, high rates of childhood overweight in girls, midlife weightgain, and postpartum weight retention may be implicated in these gender differences. Inaddition to age and gender, ranges of other sociodemographic characteristics are closelyrelated with obesity, particularly for race/ethnicity and nativity.Race/EthnicityThe 1985 Heckler report brought widespread popular attention in the United States tothe problem of racial/ethnic disparities in health. By 1998, public health attention tothe issue was rising and in a radio address that year, President William J. Clinton challengedresearchers to eliminate racial/ethnic disparities by the year 2010. In response,