Principal component analysis (PCA) score plots of isotopic abundance of plasma metabolites measured by isotope ratio mass spectrometers (i.e. glucose, palmitic, oleic, stearic, linolenic and arachidonic acids) between ZDF (fa/+) and ZDF (fa/fa) rats.

Red dots are for ZDF (fa/+) whereas green ones stand for ZDF (fa/fa) rats. Letters are the identification code of the rat. Based on the PCA, there is a clear separation of both groups along PC1 and PC3, confirming that there is an isotopic signature at natural abundance that separates ZDF (fa/+) and ZDF (fa/fa) rats.