Why Do Young Women Diet? The Roles of Body Fat, Body Perception, and Body Ideal.

Background: To assess the relative roles of body fat, body perception, and body ideals as motivations for dieting in college women.

Method: We compared 45 college women who reported having dieted with 32 who had not, using a novel computerized test of body image called the somatomorphic matrix.

Results: As expected, the difference in body fat between subjects’ “perceived body” and “ideal body” was significantly greater in dieters than in nondieters (p < .001). Remarkably, however, this difference remained highly significant even after adjusting for the subjects' actual measured body fat (p = .002). Further analysis revealed that this difference persisted, not because dieters had unrealistic ideals of thinness, but because they had distorted perceptions of their fatness.

Conclusion: Distorted body image perception, a potentially treatable condition, may play an unexpectedly large role in motivating young women to diet.