PPARG and obesity due to melanocortin 4 receptor deficiency: The mechanisms by which “obesogenic” EDs contribute to the etiology of obesity are as follows: direct promotion of adipogenesis, which increases both the number and size of adipocytes through activation of PPARγ, increased differentiation of preadipocytes towards adipose tissue through activation of PPARγ, increased fat, which promotes activation of the transcription factor of adipogenic genes.