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The groups of variables used in the PCAs are described in Statistical methods. The notation F1–F3 indicates the first to third principal components, or factors (F), derived from each group of variables. Lines connecting boxes indicate significant positive correlations (p < 0.01), and bold lines denote correlations significant at p < 0.001. Correlations labelled A–D are explained in the Results (PCA and conditional independence analysis). Veg Vegetables
