Governments, schools, and curriculum authorities are increasingly recognizing that body image during adolescence is a public health issue that warrants attention in the school setting. After 30 years of eating disorder prevention research, and given the current interest in this area, it seems timely to review the research on interventions to improve body image in schools. We reviewed universal-selective, classroom-based programs that have been conducted since the year 2000, among adolescents, and found 16 eligible intervention programs. Seven of these programs were effective in improving body image on at least one measure, from pre to post test, though effect sizes were small (d = 0.22-0.48). These effective programs were conducted among younger adolescents 12.33-13.62 years, and included activities focusing on media literacy, self esteem, and the influence of peers. Implications for school personnel and curriculum authorities are discussed, and we provide recommendations for a strategic approach to future research in this area. 3 What works in secondary schools? A systematic review of classroom-based body image programs Body dissatisfaction is common during adolescence. Approximately 70% of adolescent girls and 45% of boys want to change their body weight or shape (Smolak, 2012) . Australian adolescents have consistently ranked body image as their number one concern in the Mission Australia Survey over the past six years (Mission Australia, 2006. Similarly, levels of body dissatisfaction among adolescent girls in the USA have remained relatively stable since 1999 (Neumark-Sztainer et al., 2012) . Body dissatisfaction during adolescence has been associated with a number of negative health outcomes in prospective studies, most notably the onset of dieting and disordered eating behaviors (Neumark-Sztainer, Paxton, Hannan, Haines, & Story, 2006) . Higher levels of body dissatisfaction have also been linked to depression (Stice, Hayward, Cameron, Killen, & Taylor, 2000) , smoking (Neumark-Sztainer, , and unsafe sex practices (Schooler, 2012) , with effect sizes ranging from small to moderate. The large number of young people affected, the relative stability of this issue over the past decade, and the wide range of deleterious consequences, indicate an urgent and continuing need to develop and evaluate effective body image interventions for adolescent girls and boys. Schools are widely recognized as appropriate sites for interventions to improve body image among adolescents. They offer the potential for sustained interactions with young people at a developmentally appropriate age, where they are already in a learning environment . School-based interventions also offer opportunities to support program materials with environmental changes (Neumark-Sztainer, Levine, et al., 2006) , and a whole-school approach to health promotion (O'Dea & Maloney, 2000; Smolak, Levine, & Schermer, 1998) , particularly with younger children in more comprehensive Governments, schools, and curriculum authorities are also increasingly recognizing the potential to address body image issues in the school setting. A recent British parliamentary inquiry recommended that evidence-based body image lessons be made mandatory in primary and secondary school curricula (All Party Parliamentary Group on Body Image, 2012). However, many secondary school teachers report that they do not feel confident in selecting and delivering appropriate body image content, and they request more effective resources and training . Given the current interest in school-based body image interventions from teachers and policy makers, it seems timely to review the effectiveness of interventions designed to improve body image in the secondary school classroom, in order to inform future curriculum and program design. School-based programs designed to prevent eating disorders have been implemented since the 1980s (Neumark-Sztainer, Levine, et al., 2006) . Many of these programs did include measures of, and content about, body image as a risk factor for disordered eating, but few programs specifically focused on body image as a primary outcome. Of seven systematic reviews on interventions to date, the majority have focused on eating disorder prevention, and none have concentrated specifically on body image and body dissatisfaction (Austin, 2000; Huon, Braganza, Brown, Ritchie, & Roncolato, 1998; NEDC, 2010; Neumark-Sztainer, 1996; Pratt & Woolfenden, 2004; Wilksch & Wade, 2009b) . A separate minority of review papers have addressed the prevention of both body dissatisfaction and eating disorders (Holt & Ricciardelli, 2008; Littleton & Ollendick, 2003; NeumarkSztainer, Levine, et al., 2006). Although useful, these reviews still focus on eating attitudes and behavior change as primary outcomes of prevention, and none focused specifically on interventions in the school setting. One thorough review did focus specifically on body Running Head: WHAT WORKS IN SECONDARY SCHOOLS? 5 image, but not on schools. It was also conducted a decade ago and was not published in an academic journal (Paxton, 2002) . Although the three meta-analytic reviews (Fingeret, Warren, Cepeda-Benito, & Gleaves, 2006; Stice & Shaw, 2004; Stice, Shaw, & Marti, 2007) do consider outcomes for body dissatisfaction, none provide evidence of effectiveness specific to school settings. Three review papers have specifically focused on interventions delivered in schools, but these have not focused on body image, and instead examined nutrition education (Story & Neumark Sztainer, 1996) , eating disorder prevention (Rosenvinge & Borreson, 1999) , and the combined prevention of body image and eating problems (O'Dea, 2005) . Consequently, previous reviews are limited in their ability to provide clear guidance for teachers and curriculum authorities regarding the specific approaches and programs that will be effective in promoting body image in the classroom. (2006) interventions. In summary, it cannot be assumed that the body image programs that are effective elsewhere are also going to be effective within the classroom setting; and it is important to determine the content of effective classroom-based body image lessons in order to facilitate broader ecological approaches to prevention. Although reviews to date have been useful in identifying effective programs targeting eating behaviors and pathology, in a range of prevention settings, they are not able to provide a clear picture of the interventions that are most effective in improving body image in the classroom. As a result, it is difficult to respond to teachers, schools, policy makers and governments about 'what works' in this unique setting. Levine and Smolak The aim of this paper is to address this identified gap in the literature through a systematic review of studies evaluating body image programs that have been conducted with secondary school students in the classroom environment. We aim to assess the effectiveness of these interventions in improving body image (our primary outcome), among adolescent girls and boys, at post-test (T1-T2), and at follow-up (T1-T3). In addition, we examine their effectiveness in improving modifiable factors related to body dissatisfaction during adolescence (our secondary outcomes), from pre to post test. More specifically, these secondary outcomes refer to psychological (i.e., self-esteem, negative affect, internalization of appearance ideals) and socio-cultural (pressure to be thin, appearance comparison, and appearance teasing) risk factors. The impact of programs on eating pathology (drive for thinness, body change strategies, and disordered eating) was also considered. These factors have been associated with body dissatisfaction during adolescence in prior research (e.g., articles. Finally, all previous review papers (i.e., systematic and unsystematic reviews, and meta-analyses identified during the database searches) were scanned for additional published articles. Book chapters and theses were not included in this systematic review as their peer review status is not always reported and they are often not readily accessible. Each article was read in full to determine whether it fit the inclusion criteria for the review, and two of the authors met to agree on the inclusion or exclusion of each study. We used a strict set of inclusion criteria in order to meet our specific aims of identifying effective classroom-based body image programs, and to facilitate stronger comparisons between the programs that were identified. The inclusion criteria, and justification and explanation for each are provided below. (2) In order to provide a review of secondary school programs, we included studies where the mean age of participants was reported as being older than 12.0 years. Students enter secondary school at a range of ages around the world, but 12 is the usual age by which they have done so in Western countries. We used the mean age of the participants as reported by the authors of the studies in order to create a clear cut-off point for study inclusion, as age range was not always provided. Although programs involving participants with a mean age of less than 12 were excluded in this instance, a future review is planned to examine the evidence base for primary schools. The upper age limit was determined by the maximum age at which participants would still be in secondary schools, which is generally 18 years. (3) In order to meet our aims of determining effective classroom-based approaches, we only included studies where program materials were delivered in a classroom, face-toface setting during school hours (but programs could include homework tasks). (4) Similarly, we included only universal-selective intervention programs (but not indicated or targeted) in this review as these are most feasible for future inclusion in classroom settings. Therefore programs aimed at either co-ed groups or males and females separately were included in this review. We used Wiesz and colleagues (2005) updated definitions of the levels of prevention that were proposed by the Institute of Medicine (Mrazek & Haggerty, 1994) . Universal preventive interventions are defined as those that are "for general population groups not identified as having specific risk factors" (p. 631) and selective prevention is defined as "a strategy that targets groups who are identified because they share a significant risk factor" (p. 632) (Weisz, Sandler, Durlak, & Anton, 2005) . Indicated preventive interventions are targeted to high-risk individuals who are identified as having "significant symptoms of disorder" (p. 632), and were excluded from this review, as Running Head: WHAT WORKS IN SECONDARY SCHOOLS? 9 they are generally not feasible in the classroom setting. Examples of targeted programs that were excluded from these analyses are presented in Table 2 . (5) In order to determine the effectiveness of programs for our primary outcome of body image or body dissatisfaction, programs were included in this review only if they used, and reported the results of, at least one measure of body image or body dissatisfaction that has been validated with adolescents (as reported by the authors of the evaluation) at pre and post test. (6) Finally, we included a methodological requirement that studies were controlled. This meant that the intervention groups were compared to a comparison condition that might have been a wait-list control, engaged in an alternative intervention, or usual classroom activities. Random allocation was not required as this is sometimes not practical in the school setting. All studies that met the inclusion criteria are summarized in Table 1 . Studies were firstly categorised into three sections based on whether there were statistically significant improvements on body image measures, from pre to post-intervention. Within these sections, studies were listed in reverse chronological order, with more recent studies listed first. When two studies were published in the same year they were presented in alphabetical order. To ensure that the information summarized in this table was accurate, two of the authors (the first and second authors) independently checked and reviewed the table. Table 2 presents the reasons for excluding studies that were identified in the search strategy. These studies evaluated school-based body image programs with adolescents aged 12 and over, but did not meet the inclusion criteria for a variety of reasons as indicated in this table. Programs were first classified into three categories of effectiveness based on the significance of change on the primary outcome of body image or body dissatisfaction at post- Cohen's classifications of effect size as small (0.2), medium (0.50) and large (0.80) was used (Cohen, 1988) . Given the wide range of existing measures of body image (J. K. Thompson, 2004; Yanover & Thompson, 2009), we indicated the measure used to determine the results for each construct using a superscript, and provide details of each measure in Table 3 . For programs that included girls and boys, the results are presented separately for each gender. There were two studies where this was not possible as the authors did not report all analyses separated by gender (O'Dea & Abraham, 2000; Wade, Davidson, & O'Dea, 2003) . When analyses were conducted on the full sample and sub-samples of participants according to risk (i.e., low and high), we report only the results for the full sample, as this is represents regular classroom dynamics. In one paper, analyses were only reported for low and high-risk subsamples, so we report the results for both samples (Wilksch, Durbridge, & Wade, 2008) . Finally, in one study, separate analyses were reported only for cohorts of participants from the USA and Italy and so we report these findings separately (Wiseman et al., 2004) . The name of each program, study authors, and country in which the study was conducted were obtained from the published reports. Where no program name was provided, this is represented by 'untitled' in Table 1 12 types in our classification procedure, but made some modifications. We added one category that focussed on developmental factors [dev] such as discussions about pubertal weight gain, as this content was not covered by the other categories. For clarity, we separately identified the three socio-cultural resistance skill approaches as approaches aimed at reducing the impact of peers [peer], enhancing media literacy [ML], and programs that used a cognitive dissonance approach [CD]. We also classified psycho-education (providing information about psychological concepts) for body image [PsyBI] and eating disorders separately [PsyED]. Details of the professional background and gender of the facilitator were obtained from the methods, as were the number and length of sessions to determine the dose. The mean age of participants was obtained from the studies, or a range was used if a mean was not provided. Participant numbers were determined by adding the number of participants in the control and intervention conditions, as reported by the study authors, for males and females separately. To ensure correct interpretation and classification of the results of each study, the corresponding study authors of the articles included in Table 1 were emailed a copy of the original table (without effect sizes) and method section of this paper prior to submission for publication. We received confirmation of results from 73% of the authors (n = 11). Minor details regarding sample sizes and the gender of facilitators were changed according to recommendations from the study authors. Results We found 16 studies published in 15 separate papers (one paper compared two
REF The intervention content was adapted to the cognitive developmental level of adolescents with respect to abstract reasoning.
What works in secondary schools? A systematic review of classroom-based body image programs
Body image
Body image
Psychology Medicine