Fat or fiction? Effects of body size, eating pathology, and sex upon the body schema of an undergraduate population

- Body schema disturbances were observed amongst nonclinical, undergraduate students.
- Body size emerged as a significant predictor of body schema distortion.
- Narrow women exhibited enlarged sensorimotor representations of body width.
- Short men exhibited enlarged sensorimotor representations of body height.
- These marked sex differences cannot be explained by contraction bias alone.

Although there is a growing consensus that women with anorexia nervosa have a distorted body schema, the origins of this disturbance remain uncertain. The present investigation examined the effects of body size, eating pathology, and sex upon the body schema of an at-risk, undergraduate population. In Study 1, 98 participants mentally simulated their passage through apertures. When aperture width was manipulated, narrow and broad women over- and under-estimated their spatial requirements for passage, respectively. This relationship was exacerbated by dietary restraint. When aperture height was manipulated, short and tall men over- and under-estimated their spatial requirements for passage, respectively. Study 2 (N = 32) replicated the association between women's veridical and internally-represented widths, although no significant effects of eating pathology were observed. Our findings suggest that body schema enlargement is not necessarily pathological, and may be driven by normal perceptual biases and internalised sociocultural body ideals.