Relevance of disordered eating prevention
The high prevalence of eating disorders and disordered eating, together with their chronic tendency, high comorbidity with other mental disorders, association with serious physical and psychosocial health consequences and resistance to available treatments, as well as the fact that most individuals with eating disorders do not receive treatment, constitute powerful reasons for an approach focused on their prevention .
Lifetime prevalence worldwide for eating disorders in young women (including anorexia nervosa, bulimia nervosa and eating disorders not otherwise specified / EDNOS) is estimated at about 5% , according to the criteria for the Diagnostic and Statistical Manual of Mental Disorders (4th ed. [DSM-IV]) . Other studies report prevalence rates of about 10%, including threshold, subthreshold, and partial eating disorders [4–6]. In Spain, various epidemiological studies [7–10] report similar data, revealing a prevalence for eating disorders of 4-6% in girls and young women aged 12–21 years . In fact, eating disorders are the third most prevalent chronic illness in adolescent girls after obesity and asthma .
The more prevalent forms, threshold and EDNOS eating disorders, are marked by chronicity, relapse, distress, functional impairment, risk of future obesity, depression, suicide attempts, anxiety disorders, substance abuse, and morbidity [13–17]. Eating disorders are associated with some of the highest mortality rates for any psychological disorder . In fact, a relevant review found standardized mortality ratios of 5.9 for anorexia nervosa and 1.9 for both bulimia nervosa and EDNOS, reporting that one in 5 individuals with anorexia nervosa who died had committed suicide .
In addition, it is currently estimated that in the US 17% of girls and 11% of boys report binge eating episodes in the last month, 12% of girls and 3% of boys report vomiting to control their weight, and 24% of girls and 8% of boys report wanting to be thinner . In Spain, research has found that approximately 28% of girls and 12% of boys are engaged in unhealthy weight-control behaviors , while nearly 7% of boys and 14% of girls reached the cut-off point on instruments for assessing disordered eating behaviors and attitudes . The high prevalence of these attitudes and behaviors is a cause for concern, given that they have been shown to be associated with less healthy dietary patterns, and may have a negative effect on both physical and psychosocial health [23–31]. Moreover, these attitudes and behaviors increase the risk of weight gain, overweight status, disordered eating behaviors and the development of clinical eating disorders [32–37].
Finally, in relation to treatment resistance, clinical controlled trials show that 23% of patients with anorexia nervosa and 41% of patients with bulimia nervosa terminated their therapy prematurely . Also, non-response to cognitive-behavioral treatment, considered the most effective to date, is at around 50%, much higher than desirable [39, 40].
Progress in disordered eating prevention research
A range of disordered eating preventive programs have been developed in recent decades, and several reviews about their effects have been carried out in different settings and with different populations [1, 41–48]. Data from meta-analyses [41, 45, 46] show that larger effects were found for programs with interactive exercises focused on reduce specific risk factors that predict the onset of eating pathology (vs. psycho-educational programs), with multiple sessions (vs. single session), that were assessed with validated measures, that were delivered by experts (vs. by teachers), and that targeted high-risk individuals (vs. a universal population). In general, prevention programs conducted with adolescents targeting eating problems and eating disorders have led to improvements in knowledge, though only a small number of such programs have succeeded in improving significant disordered eating attitudes and behaviors from baseline scores to follow-up .
New challenges: moving from efficacy to effectiveness and integrated prevention of obesity and disordered eating
Prevention scientists distinguish between efficacy trials and effectiveness trials [49, 50]. Efficacy refers to the beneficial effects of a program or policy under optimal conditions of delivery , and involves the systematic and scientific evaluation of whether an intervention works.
In this type of trial, efficacy is assessed when intervention is administered under optimal conditions, in which participants are often homogeneous, and intervention is delivered by well trained and closely supervised research clinic staff [49, 50]. Efficacy is one of the two dimensions established by the American Psychological Association (APA) for the evaluation of its intervention guidelines . It should be stressed that program efficacy does not guarantee that the program will have effects under real-world conditions. Effectiveness refers to the beneficial effects of a program or policy under more real-world conditions . It is the second dimension established by the APA, clinical utility, and refers to the applicability, feasibility and usefulness of the intervention in the local or specific setting in which it is implemented . This dimension is essential for determining the generalizability to the real world of an intervention whose efficacy has been established. An important feature of effectiveness is whether the intervention has been shown to be effective when delivery is by community providers (e.g., teachers), who have many competing demands on their time and attention every day, as opposed to experts or professional researchers . This feature is one of the key standards of the Society of Prevention Research in relation to establishing the effectiveness of prevention programs .
It is in this context that, recently, there has been concern in this field about whether programs and policies developed and tested in research settings could be implemented with predictable success in schools, social agencies, and communities , which would require moving from efficacy to effectiveness trials in prevention research . A few reports have described programs of efficacy to effectiveness research in various fields of prevention, including substance abuse, childhood obesity, and HIV infection [55–57], but examples of this transition in disordered eating prevention fields are scarce.
To date, the majority of prevention trials in the disordered eating field have been efficacy trials, which tested whether prevention programs achieve effects under strongly controlled research conditions in which they are delivered by developers or closely supervised experts . However, programs worthy of dissemination must also be effective under real-world conditions and assessed in effectiveness trials. Such effectiveness trials are uncommon in this field, but are vital to progress and future research . Up to now, and to the best of our knowledge, only one targeted prevention program, The Body Project, whose efficacy had been previously evaluated , has also been assessed in an effectiveness trial . Subsequent effectiveness trials have showed that the Body Project retains its effectiveness even when it is delivered in a universal format with college students from sororities [62–65]. There are indeed other universal prevention programs whose effectiveness has been evaluated when intervention is delivered by previously-trained teachers, such as the PriMa program [66–68] or the POPS program . However, both programs lack previous efficacy trials and, in the case of the POPS program, evaluation of its results is still under way. Therefore, to the best of our knowledge, our study would be the first effectiveness trial in disordered eating universal prevention research with adolescents whose efficacy has been previously established.
On the other hand, empirically-supported reasons and practical considerations have led to eating and weight-related problems being seen as part of a continuum and to the development of interventions aimed at preventing this broad spectrum of problems . Eating and weight-related problems include anorexic and bulimic behaviors (such as fasting, vomiting and the use of laxatives, diet pills or diuretics), unhealthy dieting practices (such as dieting skipping meals), body dissatisfaction, binge-eating disorder, overweight and obesity . Reasons for this integrated approach to prevention include (i) the co-occurrence of these problems and easy progress from one problem to another over time; (ii) identification of shared risk factors; (iii) a possible lack of coherence in the messages being transmitted in the field of obesity and eating disorders prevention; and (iv) the efficiency of implementing programs aimed at preventing a broad spectrum of eating and weight-related problems, rather than using separate programs .
In particular, special attention is being paid to shared risk factors of eating disorders and obesity [70, 72–75], and calls for the development of an integrated approach to prevention in both fields are increasing [59, 70, 76–78].
However, to date, research in the two fields has followed quite separate paths. There is major concern over the possible harmful influence of preventive interventions in one field on the other–in particular, about the effects obesity prevention programs might have on variables such as body image, excessive weight concerns, weight-related teasing, or engaging in restrictive dieting and unhealthy weight-control behaviors. These effects could cancel out the efforts and achievements made in the field of prevention of disordered eating and body dissatisfaction [78–80]. This is a controversial issue: we do not know whether such unintended psychological harm occurs or not, as in obesity prevention programs the variables related to disordered eating and body image have been scarcely evaluated . In spite of this, we have indirect evidence of this possible harmful influence in the high frequency of unhealthy weight-control behaviors among overweight and obese adolescents, situated at between 30% and 70%, depending on sex and the type of population studied [21, 82, 83].
Some recent obesity prevention programs have been concerned to evaluate their potential effects on these types of variables [84, 85], and some programs aimed at preventing shared risk factors of obesity and eating disorders have been developed [60, 86, 87]. But developments in this field are still quite few and far between. As we shall see, our study also introduces some elements of this integrated approach.
The MABIC project
Our research team have developed and assessed a universal school-based disordered eating prevention program that combines the empirically supported components most commonly associated with successful interventions of the type cited above, except for those related to targeted prevention . A detailed description can be found in the published intervention manual . The efficacy of the program was assessed under strong methodological conditions, including delivery conducted by two of the developers, both professional researchers (GLG and DSC). The study was registered in the International Standard Randomized Controlled Trial Number Register (ISRCTNR) of Current Controlled Trials (no. ISRCTN07896919). The program was effective in generating positive changes in eating attitudes and beauty ideal influences at 6-month follow-up, with effect sizes greater, on average, than those obtained previously in selective-universal programs, and similar to or greater than those achieved by targeted prevention programs .
In 2009, a new research project was launched, led by our research team in conjunction with the Parc Taulí Health Corporation (CSPT in Spanish) and the Institute of Psychology Foundation (FIP in Spanish) and supported by a grant from the Spanish Ministry of Education and Innovation (no. PSI2009-08956). The present research is part of this project, and sets out to assess the effectiveness of the aforementioned program in a new effectiveness trial. The effect of the program will be evaluated now when delivered by previously trained community providers.
In line with the integrated approach, the training of community providers in the present study was based on an integrated approach to prevention. Moreover, the main outcomes were focused on shared risk factors of eating disorders and obesity. Indeed, the origin of the project’s name, the MABIC project, is a Spanish acronym for four shared risk factors of eating disorders and obesity with empirical support: “M” for media (“Medios de comunicación” in Spanish); “A” for disordered eating (e.g., dieting) (“Alimentación alterada” in Spanish); “B” for weight-related teasing, (“Burlas relacionadas con el peso” in Spanish); and “IC” for body dissatisfaction (“Insatisfacción Corporal” in Spanish). The effectiveness trial was registered in the ISRCTNR of Current Controlled Trials (no. ISRCTN47682626). Recently, our team obtained a new grant from the Spanish Ministry of Economy and Competitiveness (no. PSI2012-31077) for the MABIC-II project, a continuation of the previous one.
In sum, the main aim of this study is to assess the effectiveness of a universal-selective disordered eating prevention program, whose efficacy has been demonstrated previously, in reducing shared risk factors of eating disorders and obesity. The effectiveness will be evaluated when the program is delivered by community providers previously trained in an integrated approach to the prevention of eating disorders and obesity.