Developmental Course of Body Dissatisfaction
Age at T1 did not predict increases in body dissatisfaction for the combined sample of girls and boys; however, this relation was moderated by gender. Follow up analyses demonstrated that for girls, increases in age were associated with increases in body dissatisfaction. Although there were no significant differences between levels of body dissatisfaction for boys and girls in the sample at age 13, by age 14 girls were significantly more dissatisfied. This effect remained at ages 15 and 16. These findings mirror those described by Jones (2004)
, who also found that high-school girls endorsed higher levels of body dissatisfaction than middle school girls. Consistent with previous studies (Gardner, Friedman, & Jackson, 1999
; Hargreaves & Tiggemann, 2002
; Jones, 2004
; Presnell et al., 2004
), rates of body dissatisfaction increased overall for the girls over the 2-year course of the study, while it decreased for boys, and girls were generally more dissatisfied with their bodies than boys in the current sample at each timepoint. This is reflective of a developmental model of body dissatisfaction, wherein girls become increasingly more body dissatisfied during adolescence as they move away from the thin-ideal, and boys become more satisfied as they move toward the mesomorphic ideal (Smolak, Levine, & Thompson, 2001
). Furthermore, girls who reported satisfaction with their body size and shape were significantly thinner than boys who expressed similar levels of satisfaction. This suggests that while average weight boys are relatively content with their physique, girls' body satisfaction is correspondent with a physique that more closely approximates the current thin-ideal for females.
Risk Factors for Increases in Body Dissatisfaction
Despite this, ideal body internalization did not emerge as a prospective predictor of body dissatisfaction in this study. This is inconsistent with some previous research that has supported this relation for girls (Jones, 2004
; Stice & Whitenton, 2002
) and for boys (Jones, 2004
). However, another prospective study that examined thin-ideal internalization in a coed sample also did not find support for the predictive relation to body dissatisfaction (Presnell et al., 2004
). Ideal body internalization has been thought to lead to body dissatisfaction because of the feelings of frustration engendered by failing to attain an ideal one holds in high esteem. Because there was no interaction of gender and ideal body internalization, these null findings cannot be attributed to gender differences in the way adolescents conceptualize the ideal body size and shape. As an aside, ideal body internalization also did not interact with obesity to predict body dissatisfaction for the current sample, suggesting that this variable does not predict increases in body dissatisfaction even among those adolescents who deviated substantially from the culturally sanctioned ideal.
Curiously, in the current study BMI also did not predict body dissatisfaction for adolescent boys and girls. This is in contrast to previous research (Barker & Galambos, 2003
; Presnell et al., 2004
; Rosenblum & Lewis, 1999
), which has demonstrated that BMI is a consistent predictor of girls' dissatisfaction and, in one study (Field et al., 2001
) for boys as well. Theoretically, increases in body weight cause one's body to diverge from the ideal, thus leading to dissatisfaction (McCarthy, 1990
). Because gender did not moderate the relation between body mass and body dissatisfaction, this study does not offer evidence that body weight operates differently for girls and boys in terms of predicting body dissatisfaction, as suggested by theorists who maintain that boys strive for increases in body mass (Jacobi & Cash, 1994
; McCreary & Sasse, 2000
; Moore, 1990
; Smolak, Levine, & Thompson, 2001
). It should be noted, however, that our measure of body dissatisfaction does not distinguish between displeasure with being too large versus being too small.
It is also worth noting that whereas girls in this study showed a linear association between BMI and body dissatisfaction at all measurement points, boys deviated from a linear association throughout the duration of the study. More puzzling, boys who endorsed the highest levels of dissatisfaction with their bodies were nearly identical in weight to boys who endorsed the greatest satisfaction. This suggests that one's perception of weight may be of greater psychological relevance than one's physical dimensions. It may also be the case that BMI is too broad a measurement of the physical changes that adolescent girls and boys undergo during this important developmental phase, as it does not distinguish between weight gained via lean muscle versus fatty tissue. Thus, boys who weigh more due to increased muscle mass may be very satisfied with their physique, whereas boys whose weight increases as a result of adipose tissue may be displeased with this increase.
Initial elevations in negative affect predicted increased body dissatisfaction for the combined sample. Theoretically, the processing biases associated with affective disturbances could result in a preference for information about one's physique that confirms a negative sense of oneself (Beck, 1976
). Although consistent with a previous study that found that negative affect was a prospective predictor of boys' body dissatisfaction (Presnell et al., 2004
) this relation was not moderated by gender in this sample, and thus is difficult to reconcile with previous prospective studies that found that affective disturbances did not predict body dissatisfaction for girls (Presnell et al., 2004
; Stice & Whitenton, 2002
). To our knowledge, this is the first study to demonstrate this effect for a sample of both boys and girls.
Deficits in social support from parents—and to a lesser extent from peers—predicted body dissatisfaction for both boys and girls. Presumably, deficits in social support might escalate vulnerability to body dissatisfaction as individuals strive to gain social acceptance through conformity with idealized body images, whereas supportive relationships with friends and family might offer protection from feelings of body dissatisfaction. This relation for girls has received support in prior research (Stice & Whitenton, 2002
), although Jones (2004)
found that peer acceptance about appearance predicted girls' body dissatisfaction, but did not predict in a separate sample of boys. In the current sample, parental support deficits were a more robust predictor of body dissatisfaction than were peer social support, and remained a significant predictor of body dissatisfaction in the multivariate analyses while peer support deficits dropped out of the model. Although it is widely believed that peer influence becomes increasingly salient throughout adolescence, this study supplies some evidence that family relationships retain their relevance and remain a powerful predictor of adolescent body dissatisfaction.
As hypothesized, increases in self-reported dietary restraint predicted increases in body dissatisfaction. In theory, attempts to manage one's weight via dietary restraint could cultivate body dissatisfaction for both girls and boys because the frustration associated with dietary failure may increase displeasure with one's shape and weight. Furthermore, self-reported dieting has been found to predict weight gain (Klesges, Isbell, & Klesges, 1992
), which may also amplify feelings of body dissatisfaction. Consistent with this evidence, it has recently been suggested that identifying oneself as a dieter is a marker for a propensity to overeat, and therefore individuals who express the need to employ dietary restraint do so because they have a tendency to overeat when not actively attempting to restrict their caloric intake (Lowe & Levine, 2005
; Presnell & Stice, 2003
). Although this relation has been supported for girls (Barker & Galambos, 2003
, Byely et al., 1990), attempts to manage weight did not predict body dissatisfaction for boys in the one prospective study we located that examined this variable (Barker & Galambos, 2003
). Gender did not moderate this relation, indicating that self-reported dietary restraint does not exert differential risk for boys versus girls.
Eating pathology did not predict increases in body dissatisfaction in this study, and this relation was not moderated by gender. In theory, loss of control over one's eating, coupled with frustrating attempts to compensate for binge episodes by fasting, purging, or excessive exercise might increase dissatisfaction with one's physique due to the guilt and shame associated with such behaviors. As well, because such behaviors are associated with weight gain rather than their intended effect of weight loss, they may also increase the discrepancy between an individual's ideal and actual weight. However, in the current study this theoretical relation did not receive support.
None of the risk factors that predicted body dissatisfaction for the coed sample were moderated by gender—despite adequate power (>.88) to detect small effects in this sample (Cohen, 1988
). This is an important point, because the bulk of research in this area focuses primarily on girls, and researchers have theorized that the processes by which males and females become body dissatisfied are dissimilar (Keel, Klump, Leon & Fulkerson, 1998
; Tiggemann & Pennington, 1990
). Although girls in this study evidenced higher overall levels of body dissatisfaction than boys, the rates of body dissatisfaction among boys were not insubstantial, and the risk factors were equivalent. This suggests that interventions targeting youth at risk for developing body dissatisfaction—as well as the psychiatric outcomes that are associated with body dissatisfaction (e.g. depression, eating disorders)—should focus on both boys and girls. Results do suggest, however, that while girls uniformly wish to be thinner, boys are divided into those who desire to gain weight and those who desire to lose weight. Thus, interventions for boys may need to target both ends of the spectrum. The results of this study further indicate that an intervention aimed at individuals who express the need to diet may be especially helpful in decreasing levels of body satisfaction. Additionally, interventions that focus on increasing positive affect and peer and parental support would be particularly useful. Finally, this study indicated that the pivotal time to intervene with adolescents in order to prevent body dissatisfaction may differ for boys and girls. Boys appear to be most body dissatisfied in early adolescence, whereas girls become increasingly displeased with their physique as they progress into middle and late adolescence.
It is important to consider the limitations of this study when interpreting the findings. First, the low participation rate limits the generalizability of this sample. Second, because both the measure of body dissatisfaction and thin-ideal internalization were modified in order to include items relevant for both genders, it is possible that this may have introduced some measurement artifact. However, our results are commensurate with previous studies that have examined these constructs, increasing our confidence that they were adequately assessed. Thirdly, this study did not differentiate between dissatisfaction with body parts that are perceived to be too small versus too large, a distinction that may have important theoretical consequences—especially for boys. Finally, whereas longitudinal data provide information regarding temporal precedence, third-variable explanations cannot be ruled out with a non-experimental design. Therefore, it is possible that some shared causal variable increases both the risk factors and body dissatisfaction.