Dissonance-based prevention of eating disorder risk factors in middle school girls: results from two pilot trials.

Eating disorders in young women are prevalent and debilitating. The prevalence of DSM-5 eating disorders by age 20 among females is 13%1, and eating disorders are marked by chronicity, functional impairment, and future obesity, internalizing disorders, suicidality, and morbidity.2 However, few individuals with eating disorders seek eating disorder treatment (20% with threshold disorders; 3% with eating disorder-not otherwise specified).2 Thus, a significant public health priority is to develop and disseminate effective eating disorder prevention programs. Eating disorder symptoms tend to emerge between 16–20 years of age (e.g., peak risk periods are 19–20 years for anorexia nervosa, 16–20 years for bulimia nervosa, 18–20 years for binge eating disorder).1 However, although rates of threshold eating disorders are low prior to age 16, symptoms of pathological eating behaviors are present as early as middle school.3 In addition, established risk factors for eating disorders, including thin-ideal internalization, body dissatisfaction, dieting, and negative affect, are often present in late childhood and early adolescence. 4, 5 Thus, researchers have suggested that it would be useful to implement prevention programs during this developmental period.3, 5 Unfortunately, eating disorder prevention programs for young adolescents have shown limited effects. Some programs have not significantly reduced risk factors6 or produced significant effects for only one eating disorder risk factor.7 Others report initial significant effects on multiple eating disorder risk factors but found that effects were not sustained at follow-up.8 A few programs offered to young adolescents have demonstrated intervention effects on multiple eating disorder risk factors with some changes being sustained up to 1-year post-intervention.9, 10, 11, 12 Halliwell and Diedrichs13 found that a brief (four 20-minute sessions) dissonance-based eating disorder prevention program for 12–13 year-old girls produced significantly greater pre-post reductions in thin-ideal internalization (d = 0.49) and body dissatisfaction (d = 0.40) but not dieting, relative to waitlist controls. However, a meta-analysis of eating disorder prevention programs14 found significantly larger effects for older adolescents (i.e., 15 years of age or older) versus younger adolescents for eating pathology (M d = 0.35 vs 0.18), body dissatisfaction (M d = 0.30 vs 0.16), thin-ideal internalization (M d = 0.47 vs 0.22), and negative affect (M d = 0.35 vs 0.14), suggesting difficulty in preventing eating pathology this early. In addition, to our knowledge, no eating disorder prevention program conducted with a middle school population has produced reductions in eating disorder symptoms. The eating disorder prevention program with the strongest evidence base for older adolescent women is a selective dissonance-based intervention (the Body Project) in which young women with body image concerns voluntarily critique the thin ideal in verbal, written, and behavioral exercises.15 Criticizing the thin ideal in a group setting theoretically produces cognitive dissonance for participants who have internalized the thin ideal, leading to a reduced pursuit of this ideal, which in turn putatively decreases body dissatisfaction, unhealthy weight control behaviors, negative affect, and eating disorder symptoms, as well as future eating disorder onset. Efficacy trials show that the Body Project produces larger reductions in eating disorder risk factors and eating disorder symptoms (M pre-post d = 0.82) relative to assessment-only or alternative intervention.15, 16 Critically, the Body Project significantly reduced onset of sub/full threshold eating disorders through 3-year follow-up relative to assessment-only controls (incidence 6% vs 15% respectively; d = 0.50).16 Efficacy trials conducted by independent teams have also found that dissonance-based eating disorder prevention programs produce greater reductions in risk factors and eating disorder symptoms than assessment-only controls and alternative interventions.17, 18, 19 Effectiveness trials confirm that the Body Project produces similar effects when high school and college counselors recruit at risk young women and deliver the program in real-world settings relative to participants in educational brochure and video control conditions (M pre-post d = 0.58), including significant reductions in eating disorder symptoms that persist through 3-year follow-up (M pre-3-year follow-up d = 0.30).20, 21 Although research indicates that the Body Project is efficacious and effective for female college and high school students, three lines of evidence suggest it would be important to develop a new version of the Body Project specifically designed for female middle school students. First, we collapsed data from two large trials involving female college and high school students to characterize intervention participants who showed eating disorder onset despite completing the Body Project, as an improved understanding of factors predicting poor response might allow us to improve the program’s effectiveness.22 Results indicated that, relative to intervention participants who remained disorder-free, Body Project participants who later developed a DSM-5 eating disorder showed greater thin-ideal internalization, body dissatisfaction, negative affect, and eating disorder symptoms at baseline. Thus, implementing eating disorder prevention programs at an earlier developmental period before risk factors and symptoms become deeply ensconced may be more effective. Second, we examined developmental changes in eating disorder risk factors and symptoms from ages 12 to 20 to inform the timing of prevention delivery,23 using data from a prospective study in which participants completed diagnostic interviews and surveys annually from age 12 to 20.1 Results suggested that key risk factors (i.e., body dissatisfaction, thin-ideal internalization, negative affectivity, dieting) were already evident by age 13 and escalated only slightly thereafter, implying that it would be useful to have efficacious eating disorder prevention programs for females aged 12 to 14. These data also suggested that we should refine the Body Project to focus on reducing body dissatisfaction and negative affectivity, which were already elevated by age 13, in addition to reducing thin-ideal internalization, which is the original foci of the Body Project. Third, we conducted an initial within-subjects evaluation of the Body Project with female middle school students and found no significant pre-post reductions in thin-ideal internalization, body dissatisfaction, dieting, negative affect, or eating disorder symptoms assessed by questionnaire (M d = 0.09). Thus, our initial pilot study suggested the need to develop a version that was adapted for use with female early adolescents versus the version that has been effective for female high school and college students. We believed this was because the activities and vocabulary level were not adapted to be appealing and comprehensible to younger adolescents and because some of the in-session and home practice assignments required advanced cognitive abilities (e.g., abstract reasoning, planning) which do not routinely develop until late adolescence.24 Given these initial results, we concluded it would be necessary to substantially revise the Body Project to make it more age-appropriate. Because middle school group participants appeared distracted by the end of the hour-long sessions and had trouble clearly understanding and utilizing the intervention concepts, we converted the program to six 45-minute sessions that were simplified and more interactive. All key components of the original Body Project that we felt were age-appropriate were retained; a comparison of the components of this revised intervention relative to the original Body Project is shown in Table 1. Table 1 Contents of the Original Body Project Intervention Compared to the MS Body Project Intervention. This report describes two pilot studies evaluating the new 6-session intervention, which we labeled MS Body Project (MS for middle school). In the first pilot, 81 female middle school students randomized to the MS Body Project or assessment control condition were assessed at pretest and posttest. In the second pilot, 52 female middle school students were similarly randomized to the MS Body Project or assessment control condition but were assessed at 3-month follow-up, in addition to pretest and posttest. We targeted students with body image concerns because prevention programs targeting higher-risk individuals tend to produce larger effects than those offered universally14 and because young women with body image concerns are at elevated risk for eating disorder symptoms.4 Given the limited statistical power of these pilot studies, we focused both on the magnitude of effect sizes and statistical significance when interpreting study results.