A human study, by Rasool et al., found that in the first trimester, obesity is associated with the downregulation of lipid metabolism genes such as ACOX1, CPT2, AMPKα, LPL, LIPG, MFSD2A, ACACA, and PLIN2, which were significantly reduced in the placentas of women with obesity compared to those of lean women [29]. This evidence concerns the gene ACOX1 and obesity due to melanocortin 4 receptor deficiency.