Extreme behaviors related to exercise and eating are of increasing concern for professionals working with adolescent boys and girls (e.g., Hausenblas & Carron, 1999; Parks & Read, 1997). These behaviors are adopted by adolescents to change their bodies to match the sociocultural ideal for boys (McCabe & Ricciardelli, 200la) and for girls (Moore, 1993). For boys, the ideal is a muscular body with a large chest and shoulders and a slim waist. For girls, it is a slim overall body (Ricciardelli & McCabe, 2001a). The attainment of this ideal body is seen as being central to popularity with both same-sex and opposite-sex peers.
The present study used a biosocial framework, developed by the authors from the literature on health risk behaviors among adolescents, to determine which adolescents are at greatest risk of engaging in extreme body change behaviors (e.g., exercise dependence, disordered eating, and the use of food supplements and steroids). A longitudinal design was employed to examine the temporal relationships between variables, and to assess how changes in the biosocial variables are associated with levels of disordered eating and exercise dependence over time. The biosocial framework in Figure 1 outlines the proposed relationships between pubertal timing, popularity with peers, involvement in sport, and the development of problem behaviors associated with eating and exercise among adolescent boys and girls.
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The timing of puberty in relation to adolescent boys' and girls' peers appears to have important implications for body image and popularity (Graber, Lewinsohn, Seeley, & Brooks-Gunn, 1997). Early maturing boys are generally at a developmental advantage, both in terms of their body build conforming to the sociocultural ideal and in terms of their athletic ability, compared to late maturing boys (Silbereisen & Kracke, 1997). Late maturing boys would appear to be at greater risk of both developing higher levels of body dissatisfaction and engaging in detrimental eating and exercise behaviors to bring their bodies into line with the sociocultural ideal (Falkner, Neumark-Sztanier, Story, Jeffery, Beuhring, & Resnick, 2000; Silbereisen & Kracke, 1997). Late maturing boys may also be more likely to engage in competitive sport and have a greater focus on sport to achieve an athletically competent body (Wichstrom & Pedersen, 2001). The reverse appears to be true for adolescent girls, with late maturing girls rather than early maturing girls being more likely to have a body that conforms to the sociocultural ideal (Swarr & Richards, 1996).
Empirical studies have demonstrated that early maturing boys are viewed by others as more attractive and self-confident, are more popular with their peers, have a more positive body image, and tend to be more successful athletes than late maturing boys (Freedman, 1990). In contrast, early maturing girls tend to be less popular with their peers, show a consistently more negative body image, and are more likely to be depressed than late maturing girls (Petersen, Sarigiani, & Kennedy, 1991; Stice, Prenell, & Bearman, 2001).
The effects of pubertal timing for boys and girls, and the associated changes in body mass index (BMI), are consistent with the different cultural notions of attractiveness for men and women. Research has clearly demonstrated the role of BMI in social, educational, and psychological adjustment among adolescent boys and girls (Falkner et al., 2000). With pubertal development, girls experience a normative increase in body fat and their hips broaden. These physical changes move girls further away from society's ideal body shape for a woman. As a result, after the onset of puberty, many girls report higher levels of body dissatisfaction and a poorer self-image (Swarr & Richards, 1996). In contrast, at the onset of puberty, boys gain muscle definition and their shoulder width increases, which moves the majority of boys closer to society's ideal body shape for a man.
Among boys, there is an emphasis on athletic prowess, as this brings social recognition and popularity (Kindlundh, Hagekull, Isacson, & Nyberg, 2001). There is also a clear association between engaging in competitive sport and the development of exercise dependence (Pasman & Thompson, 1988), disordered eating (Brehm & Steffen, 1998), and the use of steroids (Drewnowski, Kurth, & Krahn, 1995). In a review of studies related to eating disorders among athletes, Hausenblas and Carron (1999) found that both male and female athletes across all categories of sport were more likely to report bulimic symptomatology than were comparison groups. Research has also consistently indicated that top athletes, as well as those at sub-elite levels, are more likely to use steroids to enhance their performance (e.g., Wichstrom & Peterson, 2001). The use of anabolic steroids is likely to achieve quick results in terms of weight gain among adolescent boys (Wang, Yesalis, Fitzhugh, & Buckley, 1994).
Exercise dependence is well recognized as a symptom of disordered eating, particularly among girls (e.g., Yates, 1991), but it has not been considered a separate construct in recent models of disordered eating (Ricciardelli & McCabe, 2001b; Stice, 2001; Varnado, Williamson, & Netemeyer, 1995). Exercise dependence has been defined as a process that compels an individual to exercise in spite of obstacles, and results in physical and psychological symptoms when exercise is withdrawn (Bamber, Cockerill, Rodgers, & Carroll, 2000; Brehm & Steffen, 1998). Other terms that have also been used to denote exercise dependence include "exercise addiction" and "obligatory exercise." In the present research, it was predicted that boys who were late maturers, who had a strong focus on sport, and who engaged in competitive sport would be more at risk of developing problem behaviors related to exercise and eating. In contrast, it was predicted that early maturing girls would be more likely to experience these problem behaviors.
Peer popularity was also included in our model. Peer popularity was expected both to be a mediator and to exert an independent influence on body dissatisfaction, body change strategies, and problem behaviors. The important role that peers play during adolescence has been highlighted in the development of body image concerns and body change strategies for adolescents (McCabe, Ricciardelli, & Finemore, 2002). Peer influence is exerted via social support, social comparison, and explicit and implicit messages conveyed in intimate interactions (Patrick et al., 1999). Because late maturing boys' bodies fail to conform to the sociocultural ideal (Pope, Olivardia, Gruber & Borowiecki, 1999), it was expected that these boys would be less popular with their peers than would early maturing boys. It was expected that early maturing girls would experience lower levels of peer popularity than would late maturing girls (Simmons, Blyth, & McKenney, 1983).
It was expected that boys who were late maturers or who perceived themselves to be low in popularity would demonstrate higher levels of body dissatisfaction and, in turn, higher levels of problem behaviors. It was expected that girls who were early maturers or who perceived themselves …