Socioeconomic status, height, and obesity in children Jason E. Murasko * University of Houston - Clear Lake, 2700 Bay Area Blvd, Houston, TX 77058, United States 1. Introduction Child obesity has become a leading health concern in recent decades. In the United States, estimated child obesity rates increased from 5% in the 1970s to 15% in the 1990s, and over this same time period the heaviest children have become heavier (Anderson and Butcher, 2006). A large collection of published research has associated childhood obesity with short-term and long- term health consequences, including diabetes, cardiovas- cular disease risk factors, and social and psychological distress (Dietz, 1998; Reilly et al., 2003; Schwimmer et al., 2003). Studies have also shown an association between obesity and poorer school performance (Crosnoe and Muller, 2004; Datar et al., 2004; Sabia, 2007). Particularly for females, youth obesity has been shown to result in reduced socioeconomic attainment (Gortmaker et al., 1993; Sargent and Blanchflower, 1994; Viner and Cole, 2005). The substantial increase in the prevalence of child obesity and its association with an array of negative outcomes suggests its strong potential as an influence on the lifecourse development of health and productivity. In seeking explanations for nationwide increases in child obesity rates over recent decades, researchers have evaluated trends of decreasing food prices, increased female labor force participation, and technological shifts away from physical activity (Anderson et al., 2003). However, explanations for overall rate increases do not help explain why some children are more prone to excess body fat than others. Population heterogeneity in obesity has been associated with individual, family, and environ- mental characteristics including parental fatness, race/ ethnicity, family size, and neighborhood characteristics (Anderson and Butcher, 2006; Classen and Hokayem, 2005; Do et al., 2007). Most research aims to establish the individual associations between these variables and obesity. This is an important endeavor, but it is possible that some characteristics interact with each other in a way that influences energy imbalance differently from their individual effects. There is reason to believe that such an Economics and Human Biology 7 (2009) 376–386 ARTICLE INFO Article history: Received 16 May 2008 Received in revised form 18 April 2009 Accepted 20 April 2009 Keywords: BMI Child obesity Height Poverty Socioeconomic status ABSTRACT The substantial increase in the prevalence of child obesity over recent decades and its association with a number of negative health and economic outcomes suggests its strong potential as an influence on the lifecourse development of health and productivity. This paper evaluates interactive effects between family socioeconomic status (SES) and height on child obesity in the United States. Using the 1999–2006 National Health and Nutrition Examination Surveys (NHANES), the results of this paper confirm previous findings that taller children exhibit greater propensity towards obesity as measured by body mass index (BMI) and that obesity is inversely related to family SES as measured by poverty status. The analysis adds to the existing literature by showing that the magnitude of the SES–obesity association is larger in taller children. Age and sex patterns are evaluated that suggest the SES–height interaction persists through childhood and adolescence in males but is only evident in females during adolescence. Interaction effects are also shown to be most evident in white males and Hispanic females. Policy implications are discussed and directions for future work are suggested. ß 2009 Elsevier B.V. All rights reserved. * Tel.: +1 281 283 3107. E-mail address: muraskoj@uhcl.edu. Contents lists available at ScienceDirect Economics and Human Biology journal homepage: http://www.elsevier.com/locate/ehb 1570-677X/$ – see front matter ß 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.ehb.2009.04.004