Principal axis exploratory factor analysis was used to derive a composite dietary restraint factor from the 10 standardized DEBQ restraint scale items and the 5 standardized EDE-Q restraint scale items. Two Eigenvalues were greater than one (8.76, 1.01), thus a two-factor solution was initially extracted. However, analysis of the scree plot suggested a clear break after the first factor solution. Therefore, we retained a one-factor solution that accounted for 55.7% of the variance in the 15 restraint items. All items had loadings greater than .40 on the first factor and, with one exception, loaded lower than .40 on the second factor. The EDEQ item 4 had a loading of .46 on factor 2, but it was retained due to its content similarity to factor 1 and its high loading on the primary factor (see Table 3 for factor loadings). Items were summed to derive a composite dietary restraint factor that would be used in subsequent analyses.
