PPARG and obesity due to melanocortin 4 receptor deficiency: These findings support the hypothesis that chlorogenic acid and caffeic acid are the active compounds preventing diet-induced obesity; however; we observed that caffeine, chlorogenic acid and caffeic acid failed to inhibit MDI-induced PPARγ expression in 3T3-L1 cells, suggesting that they are not the ingredients of coffee inhibiting adipogenesis [20].