You are thinner than you think. (PART 2)

Accuracy of body size estimation: Role of biopsychosocial variables

The results of this study demonstrated that participants were more accurate in estimating the five vase regions than they were in estimating the five body regions, suggesting that other factors were involved in body image distortion. These findings are consistent with other studies that have employed inanimate objects, where participants accurately estimated the size of inanimate objects but were inaccurate in their estimation of their own size.

The degree of estimation accuracy of specific body sites may vary according to the emphasis placed on them from sociocultural messages. Given that sociocultural influences predominantly emphasize the chest for men, and the hips, waist and thighs for women, it was expected that women would overestimate their waist, hips and thighs, whereas men would overestimate their chest region. However, this hypothesis was not supported, since it was found that men and women were very similar in the extent to which they overestimated the size of the five body regions. These findings are consistent with previous studies that have found that both men and women overestimate body size. Discrepancies across studies may be due to methodological differences, such as the type of apparatus used to measure estimates of body size, randomised estimations of width or varying distance of participants from the stimulus materials.

Alternatively, the current results may suggest that men and women are now focused on all aspects of their bodies, as they both attempt to achieve a slim toned (for women) and muscular body (for men). However, an interesting finding from the current study is that by men overestimating their body size, it is likely to bring them closer to the muscular sociocultural ideal for men. In contrast, overestimation would move women further from the sociocultural ideal for women. These findings suggest that just as men evidence lower levels of body dissatisfaction than women, men may also be more likely than women to perceive that their bodies conform to the sociocultural ideal for their gender. Future research needs to focus more closely on the relationship between the ideal body of men and women and their accuracy of body size estimation.

Although men and women were found to overestimate each of the five body regions, the source of overestimation may be different. As suggested above, women may have overestimated their body size because they believed they were ‘fatter’ than they really were, and men may have overestimated their size because they perceived themselves to be more ‘muscular’ than their actual size. A possible way of clarifying whether or not this was the case would be to include a question on the body image computer program, prior to participants adjusting their ‘actual’ body size, asking whether the image on the screen ‘should be fatter’, ‘should be slimmer’ or ‘should be more muscular’.

BMI was a significant predictor of the estimation accuracy of four of the five body parts for men, but did not predict the estimation accuracy of any body parts for women. Larger men were more likely to perceive they had a larger body size for each of their body parts (except for the calves), but accuracy of body size estimation was equally likely to occur for women independent of their BMI. This result is consistent with the finding that women of all weights and sizes are attempting to obtain a slimmer body through internalization of the thin ideal, and may be both dissatisfied with their body, as well as likely to inaccurately estimate the size of their body. In contrast, male body image may be more dependent upon BMI, with men with a higher BMI perceiving themselves to be larger than their actual size, and men with a lower BMI perceiving themselves to have a less muscular body build. Past research has demonstrated the normative nature of body dissatisfaction among women, whereas significantly lower proportions of men are dissatisfied with their body, and dissatisfaction may be particularly characteristic of overweight and underweight men. Unfortunately, the current study was not able to examine the impact of muscularity versus body fat in terms of the extent of accuracy of body size estimation among men.

Depression was a significant predictor of women's estimation accuracy for three out of five body parts (all lower body parts), but did not predict estimation accuracy for men. These findings are consistent with those obtained by others in relation to body dissatisfaction among women. However, as for the studies on body dissatisfaction, the direction of this relationship is unclear, as recent evidence suggests that it may be depression that leads to body image disturbance, rather than vice versa. As for body dissatisfaction, these results indicate that there is a much weaker association between accuracy of body size estimation and negative affect for men compared to women. Women's sense of self appears to be more strongly associated with their body image than for men, and so they perceive their bodies to be larger than they are. If they are feeling depressed they may, then, be more likely to feel bad about their body as well as feel bad about other aspects of themselves. This proposal needs to be empirically evaluated.

The results of the study demonstrated that perceived sociocultural influences to both lose weight and increase muscle predicted accuracy of body size estimation for both men and women. Not surprisingly, the direction of these influences were different for men and women: higher pressures to lose weight increased estimation inaccuracy for women and reduced it for men; higher pressures to increase muscles increased estimation inaccuracy for men and reduced it for women. The most consistent sociocultural factor to predict estimation inaccuracy of each of the body parts for men was higher levels of perceived peer influence to increase muscles, with higher levels of perceived media pressure to increase muscles as well as lower levels of both media pressure to lose weight being important predictors. For women, the most consistent sociocultural influence was lower levels of perceived media pressure to increase muscles, with both higher levels of both perceived media pressure to lose weight and perceived pressure from peers to lose weight also playing a significant role in the accuracy of body image estimation. These findings applied to the estimation of all body parts, including those more closely related to the sociocultural ideal for each gender prescribed by society.

These results suggest that the peer messages most strongly predictive of body image accuracy estimations were those most closely related to the stereotyped behaviors of that gender: increasing muscles for men, and losing weight for women. However, the media messages that predicted the accuracy estimations of body for both men and women related to both losing weight and increasing muscle. The images that are portrayed by the media are slim toned bodies for both men and women, and this media ideal appears to impact on increasing muscle and losing weight for both men and women. Clearly, this proposal needs to be explored further in future studies.

The finding that only moderate proportions of the variance of the perceptual distortion could be explained by the variables included in the current study indicates that other variables that were not included may represent significant predictors of estimation accuracy. For example, a study of body size estimation among college females and found that size overestimation was associated with visuospatial dysfunction. The role of visuospatial ability in one variable that could be explore further in future research in this area.

The findings in the current study are limited by the small sample size, the limited range of predictor variables, and the limited age range of respondents. Clearly, the findings from this study need to be replicated with a larger study before we can draw strong conclusions. The current study only included a limited range of predictive variables, and these need to be extended in future studies. A broader range of respondents also need to be included, so that we can determine the generalizability of the findings to other age group and other cultural groups. Future studies also need to include a control condition that involves distortion of a male (for men) or female (for women) body other than their own, to control for estimation accuracy effects inherent in adjusting for the size of particular body parts in a body other than one's own body.

In conclusion, the findings of the study revealed that both men and women demonstrate estimation inaccuracies in their body image. No significant gender differences in the degree of estimation inaccuracies were found. However, different biopsychosocial variables were found to predict the degree of estimation accuracy among men and women. The findings of the current study support the assertion that the accuracy of body image estimations is not exclusively a defining factor of eating disorders, as these estimation inaccuracies are a phenomenon also found among the general population. It is proposed that developing a greater understanding of the degree and nature of body estimation accuracy in the normal population will provide invaluable information in our understanding of body image disturbance, and so inform intervention and prevention programs in this area.