درونی سازی اختلال تغذیه ای و ایده آلی بدن لاغر و عضلانی در نوجوانی: اثرات واسطه اعتماد به نفس بدن

This study investigates body esteem factors (weight-esteem and appearance-esteem) as mediators of the relationship between ‘internalization of the ideal body figure’ and disordered eating behaviors (restrained, emotional and external eating) in a community sample of adolescent males (n = 810) and females (n = 1137) from the Ontario Research on Eating and Adolescent Lifestyles (REAL) study. Mediation models were examined using a bootstrapping approach to test indirect effects and indirect contrasts. In males, weight-esteem partially mediated the relationship between muscular ideal and restrained eating; appearance-esteem partially mediated effects in the emotional and external eating regressions. In females, both weight-esteem and appearance-esteem partially mediated the relationship between thin ideal and all three forms of disordered eating; weight-esteem was a stronger mediator for restrained eating, and appearance-esteem a stronger mediator for emotional and external eating. Body esteem is important to consider for prevention and treatment of disordered eating in both genders.

‘Internalization of the ideal body figure’ has been suggested as a major risk factor in the development of body image disturbance and disordered eating behaviors (Low et al., 2003, Stice et al., 1994 and Thompson and Stice, 2001). Exposure to ‘ideal body’ images depicted in the media has been blamed for the pursuit of thinness in girls and muscularity in boys (Ricciardelli and McCabe, 2004, Smolak and Stein, 2006 and Thompson and Stice, 2001), as the standards for the ideal body figure portrayed in the media represent unattainable standards for most people (Jones, 2004 and Thompson and Stice, 2001). Therefore, when an individual internalizes the prevalent idealized body figure and adopts it as his or her own personal standard, he or she becomes at risk for body dissatisfaction, a precursor to a wide range of disordered eating behaviors (Grabe et al., 2008, Stice and Shaw, 2002 and Thompson and Stice, 2001). Body dissatisfaction and a major risk factor for the development of eating disorders (Gilbert et al., 2009, Polivy and Herman, 2002, Shisslak and Crago, 2001 and Stice et al., 1994), tends to increase with age, and peaks during the adolescent years, especially in females (Littleton & Ollendick, 2003). Compared to girls, adolescent boys have a lower risk of developing eating disorders (Ricciardelli & McCabe, 2004). While approximately 60% of girls report being dissatisfied with their body, only about 30% of boys report similar concerns (McCabe and Ricciardelli, 2001 and Wood et al., 1996). However, Labre (2002) suggests that problems associated with the pursuit for muscularity are increasing in males. Boys not only report a wish to develop more muscle tone (Jones, 2004, Labre, 2002 and McCabe and Ricciardelli, 2001), but they also express concerns about thinness (Stanford & McCabe, 2005). It could be that boys wish to pursue both muscularity and thinness simultaneously in order to achieve a lean, toned look. Indeed, in their study of middle school boys and girls, Smolak, Levine, and Thompson (2001) found that, even after controlling for body mass index (BMI), internalization of the muscular ideal in boys was associated with the use of weight loss techniques. Popular weight loss strategies among adolescents include dieting and calorie restriction (Paxton et al., 1999 and Valois et al., 2003). However, these weight loss techniques put individuals at risk for eating disorders including anorexia nervosa and bulimia nervosa (Stice, Presnell, Groesz, & Shaw, 2005). In addition to dietary restraint, external and emotional eating have also been identified as forms of disordered eating behaviors (van Strien, Frijters, Bergers, & Defares, 1986). External eating involves reacting to external cues for food intake (e.g., eating because other people are eating, eating during meal preparation or in response to the sight or smell of food) rather than relying on internal cues, such as hunger. Emotional eating refers to excessive eating in response to emotional experiences such as anxiety or anger (van Strien et al., 1986). This pattern, linked to attempts to improve one's mood through the consumption of food, has been identified as a precursor to binge eating in a longitudinal study of adolescent girls (Stice, Presnell, & Spangler, 2002). Much of the research on body dissatisfaction and disordered eating has focused on adult and adolescent females (e.g., Durkin and Paxton, 2002, Gilbert et al., 2009, Groesz et al., 2002, Harrison and Cantor, 1997 and Stice et al., 1994), and only recently have researchers begun to draw their attention to body image concerns in males (e.g., McCabe and Ricciardelli, 2001 and Stanford and McCabe, 2005). At this point, relatively little is known about the specific pathways that link internalization of the muscular ideal and disordered eating in adolescent males. Further, much of the disordered eating literature focuses on restraint. While restraint certainly appears to be a major factor in the development of anorexia and bulimia (Ricciardelli et al., 1997 and Stice and Shaw, 2002), emotional and external eating are also important patterns to examine in relation to disordered eating in non-clinical samples, especially given their association with binge eating episodes. In an attempt to further understand the development of disordered eating among adolescent males and females, the present study investigates body esteem factors as mediators in the relationship between internalization of the ideal body figure and disordered eating behaviors in a large school-based sample. Body esteem is similar to body dissatisfaction in that it refers to self-evaluations of one's body appearance (Mendelson, Mendelson, & White, 2001), but body esteem scores reflect the degree of satisfaction rather than dissatisfaction with one's body appearance. Two body esteem factors are of particular interest in the present study, namely weight satisfaction and general feelings about one's appearance, herein referred to as weight-esteem and appearance-esteem, respectively. We investigate the extent to which the relationship between internalization of the ideal body figure and eating behaviors is mediated by body esteem. Specific hypotheses were generated based on previous research findings. We propose that weight-esteem in girls will mediate the relationship between internalization of the thin ideal and restrained eating. This pathway is hypothesized based on the strong link established between weight dissatisfaction and dieting, among other forms of restrained eating (Ricciardelli et al., 1997 and Stice and Shaw, 2002). In males, we hypothesize that appearance-esteem will mediate the relationship between internalization of the muscular ideal and restrained eating. Boys also seem to be concerned about thinness, although to a lesser extent than girls (McCabe and Ricciardelli, 2004, Stanford and McCabe, 2005 and Wood et al., 1996); this concern is likely related to the toned and lean look promoted in the muscular ideal. Therefore, we propose that appearance-esteem will be a more important consideration than weight-esteem in males in the restrained eating model. Pathways across the other forms of disordered eating, i.e., emotional eating and external eating, are also explored.