of coverage from interpersonal variables to potential consequences of a broader “toxic environment;” however, these studies generally did not collect DNA or use genetically informative designs. Hence, there appears to be room for greater scientific synergy between the domains.

There are two overarching aims to the present report: (a) to review evidence for genetic and social-environmental influences on obesity, respectively, and the types of methodologies used to establish these associations, and (b) to consider opportunities for greater methodological synergy between the two domains. The report strives to foster ideas for new research that bridge genetic and social-environmental research, as they relate to obesity and obesity-promoting behaviors. Conceptual frameworks that posit potential interactions or covariation among genetic and social environmental factors are proposed.


Figure C-1 presents the conceptual framework around which the present report is organized. The model posits that genetic and social-environmental factors promote obesity through their independent influences on intermediary behavioral variables. These intermediary phenotypes may induce a positive energy balance (i.e., greater energy intake than expenditure) that, when sustained, promotes obesity. Although physiological variables are not depicted in the model, they clearly are central to energy balance regulation and the putative behavior phenotypes listed in the figure. The model is intended to reflect much of the current literature, in that correlations or interactions among the social environment and genetic factors are not explicitly posited. However, as reviewed in this report, certain studies challenge this assumption and suggest that expansions of this model may help guide future research. The final section of this report suggests additional research that would test interactions and correlations among genetic and social-environmental variables.

The following section of the report, Section 3, addresses putative social-environmental influences on obesity-promoting behaviors and obesity, corresponding to pathways b and c in Figure C-1. Section 4 addresses evidence for selected refined behavioral traits that have been associated with obesity in some studies, corresponding to the “putative behavioral phenotypes” noted in the figure. Section 5 addresses putative genetic influences on obesity-promoting behaviors and obesity, corresponding to pathways a and c in the figure. Section 6 addresses evidence for potential interactions among genetic, social, environmental, and behavioral influences on obesity. The data presented in this section challenge the premise that genetic and environmental factors do not interact or cannot influence each other. Section 7 suggests additional research questions and designs that

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