Lipid abundance heat maps by chain lengths and saturation in obese vs lean participants. Heat maps of log₂-transformed abundances of lipids selected by partial least squares–discriminant analysis (PLS-DA) for A, triacylglycerols (TAGs) and diacylglycerols (DAGs); and B, cholesterol esters (CE), ceramides (CER), dihydroceramides (DCER), free fatty acids (FFA), hexosylceramides (HCER), lactosylceramides (LCER), lysophosphatidylcholines (LPC), lysophosphatidylethanolamines (LPE), phosphatidylcholines (PC), phosphatidylethanolamines (PE), and phosphatidylinositols (PI).