FASN and obesity due to melanocortin 4 receptor deficiency: DHEA can decrease liver and adipose tissue G6PD and fatty acid synthase activities, can decrease serum insulin and cholesterol as well as decrease hepatic acyl-CoA cholesterol-acyl transferase activity, and can reduce fat accumulation in both genetic- and diet-induced obesity models, which can have protective effects against insulin resistance induced by a high-fat diet [8].