[warning: this is *really* long.]
so the survey had two parts: a measure of body dissatisfaction and a measure of disordered eating. the survey also asked for height, weight, waist and hip measurements. from these, i calculated BMI and waist-to-hip ratio (WHR). i distributed the surveys to ed_ucate for an sample population of people with eating disorders and to my campus as a control population. i originally intended to include both men and women, but the small number of male responses from here [i think there was one] forced me to have an all-female study.
i was primarily looking for a the relationship of the WHR to body dissatisfaction and disordered eating. a little background on the significance of the WHR: it is associated with various health implications. for example, a high WHR [this means that there are less curves and more of a straight body] is associated with obesity. in contrast, a low WHR [so, a smaller waist and larger hips, relatively speaking] is associated with increased fertility in women because the fat stored in the hip region is preferentially utilized during pregnancy and lactation. by the same token, higher WHR are associated with decreased fertility. women with higher WHR have a more difficult time becoming pregnant -- naturally or artificially.
evolutionary psychology is an approach to the human mind that views its functions as adaptations or byproducts thereof. this approach hypothesizes that there are various mechanisms in the mind that, over evolutionary time [i.e., millions of years], have responded to adaptive dilemnas. one of the most pressing evolutionary challenges is reproduction. this is how adaptations survive -- they must be reproduced. because the WHR deals with reproduction, evolutionary psychologists proposed that there will be mental adaptations that favor healthy WHRs. this is supported by numerous studies [including cross-cultural ones] that found that men and women prefer the female body shape to have a low WHR [again, that is a smaller waist in relation to the hips -- the "pear" or "hourglass" shape, as it were]. this holds true, regardless of the cultural preference for body SIZE.
this is an important distinction that i just want to stress. these studies did find variation on body size preference, as we all might expect. but the preference for a certain body SHAPE remained constant. [nevertheless, in my study i examined body size, BMI, as it related to body dissatisfaction and disordered eating.]
given this basis, i wanted to explore how the WHR affects body dissatisfaction and disordered eating. obviously, if there is a preference for a certain body shape, you would expect that anyone not conforming to that "ideal" might become dissatisfied with their bodies. and further, because body dissatisfaction is a major component of eating disordered, that the WHR might play into the development of disordered eating.
i analyzed the data from the two populations [ed_ucate and the control] seperately. what i found was interesting and surprising.
the trends from the two populations were EXACTLY THE OPPOSITE on every correlation examined. these were: WHR and body dissatisfaction; BMI and body dissatisfaction; WHR and disordered eating; and BMI and disordered eating.
so, in the ed_ucate sample, a higher WHR was associated with increased body dissatisfaction and disordered eating, as was predicted by the evolutionary theory. yet in the control population, the opposite was true. there are only two explanations from the existing research that might explain this. first, one study found that people think that women with a low WHR weigh more than someone of the same BMI but with a higher WHR. in other words, fat deposition in the hips makes one appear to weigh more. this *might* explain why women in the control population with low WHR are more dissatisfied with their bodies -- because they think they look like they weigh more. [a higher BMI, by the way, in the control sample was correlated with increased body dissatisfaction - no surprise there, but more on that later.] but this explanation doesn't explain the trend in the ed_ucate sample.
the other explanation that i think better explains this pattern comes from a study that examined depression and body dissatisfaction in relation to the WHR. the researchers found that depressed women with higher WHRs were more dissastisfied with their bodies, whereas non-depressed women were dissatisfied with their bodies when they had lower WHRs. this is just like the split trends in my study, except depression in place of an eating disorder. the authors claim that "depressive realism" makes these women aware that their body shapes [with a high WHR] are unattrative and therefore they are more dissatisfied with their bodies. this prediction is in part supported by other research, which found that women with eating disorders have a more accuate view of their attracitveness because their ratings of their bodies matched those of two objective panels. [this is in contrast to women without eating disorders, who said rated themselves to be more attractive than the panels rated them.]
so, on the whole, the second explanation is better than the first, but i don't think it entirely explains why there was such a difference between the ed_ucate sample and the control sample. an area for future research.
another interesting result is that BMI had absolutely NO correlation with disordered eating in the ed_ucate sample, further proving what we all know, that just because you're not skinny doesn't mean you can't have an eating disorder. however, the results did indicate that ed_ucate women with lower BMIs are more dissatisfied with their bodies [which is, if you'll recall, the opposite of the control population]. to me, this goes to show the sad reality of an eating disorder -- you can never be thin enough. in fact, the thinner you become, the more unhappy you become as well.
the last significant thing i found was the relationship between body dissatisfaction and disordered eating. as we all might expect, higher body dissatisfaction was associated with higher measures of disordered eating in both the ed_ucate sample and the control sample. BUT, the relationship was less strong in the ed_ucate population. this again goes to prove a reality of an eating disorder: it encompasses a varitey of factors that extend beyond appearance concerns.
if you have any questions, please ask. i tried to be as clear as possible, but because i know this stuff so well, i may not have explained it as thoroughly as i should have. also, if you are interested in reading more or if you want any of my references, i will be glad to supply the sources to you.
so what do you think?! :)