Fucosterol exhibits an anti-adipogenic ability in vitro, which inhibits adipocyte differentiation and lipid accumulation by downregulating SREBP-1, PPAR-γ, and C/EBP-α, as well as the regulation of multiple signaling pathways (phosphoinositide 3-kinase/Akt and extracellular signal-regulated kinase-dependent forkhead box protein O signaling pathway) that play an anti-obesity role. The gene discussed is PPARG; the disease is obesity due to melanocortin 4 receptor deficiency.