BBS2 and obesity due to melanocortin 4 receptor deficiency: The aim of the study was to compare the metabolomic profiles of saliva, gingival crevicular fluid (GCF) and serum between ALMS/BBS patients and heterozygous carriers (n = 33) in relation to participants with simple obesity (n = 20) and healthy controls (n = 30) using gas chromatography coupled to mass spectrometry (GC-MS).