Targeted and untargeted metabolomics platforms
weight loss
Acylcarnitines (24) amino acids (22), biogenic amines (12), glycerophospholipids (90), and sphingolipids (15) were quantified using the LC with tandem MS (LC-MS/MS)-based AbsoluteIDQ p180 Kit (Biocrates Life Sciences AG), following the manufacturer’s protocol. Additional acylcarnitines (26) were quantified after extraction with methanol in the presence of deuterated standards and butylated before analysis using liquid chromatography coupled to a Sciex 5500 mass spectrometer (Sciex) (LC-MS/MS) following a previously described method [For the GC-MS analysis, metabolites were extracted from 40 μL plasma by ice-cold methanol:HPlasma samples were randomized to exclude batch variation, ensuring a proportional number of samples from the 2 dietary challenges, collected before and after the weight loss intervention and from men and women. Quality control plasma samples (Recipe chemicals and instruments) were included in each batch of samples to control for analytical drifting.