Supplementary file 1_What size and shape am I?.docx

This study tested an integrated model of perceptual, attitudinal, and interoceptive influences on women’s judgments of their own body size.</p>Methods<p>In a sample of 269 adult women, behavioural measures of body size estimation were combined with network analysis, exploratory factor analysis, and regression modelling to distinguish psychological processes exerting direct versus indirect effects on self-estimated body size.</p>Results<p>Three central findings emerged.

First, contraction bias in perceptual body size estimation was robustly replicated, with lower-BMI individuals overestimating and higher-BMI individuals underestimating their body size. Second, attitudinal body image concerns independently shifted self-estimated body size upward across the BMI range, acting additively rather than interactively with contraction bias. Third, the network and factor analyses demonstrated that attitudinal body image comprised four interconnected domains: Body Image, Mood, Interoceptive Sensibility, and Sociocultural Pressure.