Shared Risk and Protective Factors for Overweight and Disordered Eating in Adolescents

Background

Weight-related problems, including obesity, eating disorders, and disordered eating, are major public health problems in adolescents. The identification of shared risk and protective factors for these problems can guide the development of relevant interventions to a broad spectrum of weight-related problems. This paper examines the prevalence and co-occurrence of overweight, binge eating, and extreme weight-control behaviors (vomiting, diet pills, laxatives, and diuretics) in adolescents and identifies shared risk and protective factors from within the socioenvironmental, personal, and behavioral domains for these three adverse weight-related outcomes.

Methods

Data were collected at Time 1 (1998–1999) and Time 2 (2003–2004) on 2516 adolescents participating in Project EAT (Eating Among Teens). Data were analyzed in 2006–2007.

Results

Weight-related problems were identified in 44% of the female subjects and 29% of the male subjects. About 40% of overweight girls and 20% of overweight boys engaged in at least one of the disordered eating behaviors (binge eating and/or extreme weight control). Weight-teasing by family, personal weight concerns, and dieting/unhealthy weight-control behaviors strongly and consistently predicted overweight status, binge eating, and extreme weight-control behaviors after 5 years. Family meals, regular meal patterns, and media exposure to messages about weight loss were also associated with weight-related outcomes, although the strength and consistency of associations differed across outcomes and gender.

Conclusions

Weight-specific socioenvironmental, personal, and behavioral variables are strong and consistent predictors of overweight status, binge eating, and extreme weight-control behaviors later in adolescence. These findings support the need for research to determine if decreasing weight-related social pressures, personal weight concerns, and unhealthy weight-control behaviors can contribute to reductions in obesity in children and adolescents.

Introduction

Weight-related problems, including obesity, eating disorders, and disordered eating behaviors such as unhealthy weight-control practices and binge eating, are major public health problems in adolescents given their high prevalence and adverse health consequences.1, 2, 3, 4, 5, 6 Research suggests that these weight-related problems can occur simultaneously, increase in severity over time, and lead to the onset of different weight-related problems.7, 8, 9 These observations suggest a need for developing interventions to simultaneously prevent a spectrum of weight-related problems.10, 11, 12, 13, 14 Such an integrated approach could have advantages in terms of cost effectiveness, practicality, and consistency of public health messages.¹³

Behavioral research suggests that interventions will be more successful if they address factors that have been found to influence targeted outcomes.¹⁵ Thus, if effective integrated prevention approaches are to be developed, it is essential to identify predictors of multiple weight-related problems, both shared risk and protective factors. A review of the literature suggests that little research has investigated the shared risk and protective factors for obesity and eating disorders, although there is some theoretic and empiric support for the existence of such factors.¹⁴ For example, dieting can be a precursor to an eating disorder16, 17, 18, 19, 20 and can also increase risk for binge eating and weight gain over time.8, 21 Additionally, media use may increase risk for unhealthy weight-control behaviors and eating disorders through its negative effect on body image.22, 23 Media use, particularly television viewing, also may increase risk for obesity through the encouragement of sedentary behaviors and promotion of high-calorie foods.24, 25, 26

The authors are unaware of any large population-based studies on adolescents that have presented a comprehensive analysis of shared risk and protective factors for both obesity and disordered eating. While it is possible to review the obesity and eating-disorders literature to identify shared risk and protective factors, comparisons across studies can be difficult to interpret due to methodologic differences in study populations, time frames, assessment of variables, and data analysis. Many of these limitations could be addressed by examining risk and protective factors for a broad spectrum of weight-related problems within the same study.

The current study examines the prevalence of adolescent overweight, binge eating, and use of extreme weight-control behaviors, and their simultaneous occurrence. This study further examines 5-year longitudinal associations among socioenvironmental, personal, and behavioral variables and these three weight-related problems, to identify shared risk and protective factors for the occurrence of these problems. The aim of this paper is to inform the development of interventions to prevent a broad spectrum of weight-related problems. If risk and protective factors relevant to multiple weight-related problems in adolescents can be identified, the next step will be to design interventions to address those shared risk and protective factors, and thus target multiple weight-related problems simultaneously. Since the aim is to inform the development of prevention interventions, the focus is on factors that are commonly addressed within either obesity or eating-disorder interventions,27, 28 are potentially modifiable, and are suitable for addressing within health promotion programs for home, school, or community settings (Figure 1).