Beyond BMI

In June 2013, the American Medical Association (AMA) declared obesity a disease. This decision sparked debate both within the medical sphere and among the general public. In particular, the AMA was critiqued for making this decision against the advice of their delegates charged with disease deliberation, the Council on Science and Public Health (CSAPH). The CSAPH advised against disease status because of obesity's reliance on body mass index (BMI). BMI is a measurement tool used to classify individuals based on weight and height, calculated as weight divided by height squared (W/H2), and has been the standard metric for weight classification for since 1977 (Bray, 1979). It is routinely criticized as a crude, flawed measure, incapable of providing useful information about an individual's health. Highlighting its limitations, social scientists have critiqued BMI as a way to expose obesity research as a problematic field. This thesis builds on existing social science literature by moving beyond an external critique of the field. That is, this research seeks to understand the field formation of obesity research and role of BMI within the field. To do so, I ask three overarching questions: 1) when and how did obesity science form in the United States? 2) how do obesity researchers make sense of obesity's label as both a disease and epidemic? and 3) how does BMI operate, and with what meaning(s), in clinical research settings? Following qualitative methods of grounded theory (Corbin & Strauss, 2008; Strauss & Glaser, 1967) and situational analysis (Clarke, 2005), this thesis utilizes content analysis of historical and contemporary medical literature on obesity and the development of BMI, in depth interviews with prominent obesity researchers, and participant observation at ObesityWeek 2014. Chapter 1 provides an introduction to social science scholarship on obesity and sets the stage for a science and technology studies (STS) approach to obesity science. Chapter 2 builds on field formation literature to explore the development of obesity research as a knowledge field. It articulates rhetorical strategies used to expand and sustain the field and some of the obstacles obesity research faces as a multidisciplinary knowledge field. Chapter 3 hones in on the role of BMI in obesity research from its formation to the contemporary area. It illustrates how BMI has been come a stabilization tool within the field, despite its limitation as a measurement tool; how researchers make sense of BMI in their clinical work; and some of the ways in which BMI's framing power influences research design. Finally, Chapter 4 brings forward three main conclusions of this thesis. In short, "Beyond BMI: Conceptualizing Health in the 'Obesity Epidemic'," argues that 1) BMI serves as a crucial tool for the field of obesity science to stabilize its multiple disciplines, standardize research and bodies, and to articulate adiposity's risks and health complications, 2) obesity's framing as complex enables scientists to defend abnormalities in research findings without disrupting the BMI paradigm and to justify continued research investment and diversification of the field, and 3) meta-level problematic framing of the obese condition impacts obesity researchers' willingness to accept more complex relationships between obesity and health.