The process by which stem cells become fat cells.Precursor cells (pre-adipocytes) differentiate into mature adipocytes through a regulated program involving PPAR-γ and C/EBP transcription factors. Several metabolic peptides including AOD-9604 and GLP-1 analogs have proposed mechanisms involving inhibition of adipogenesis or promotion of adipocyte apoptosis — though the in vitro evidence for these effects often does not translate cleanly to human fat loss outcomes.