PPARG and obesity due to melanocortin 4 receptor deficiency: Furthermore, aging, persistent unloading (such as in patients with paraplegia or those on prolonged bed rest) or intermittent exposure to reduced forces (such as in astronauts exposed to microgravity) [23], and obesity but also caloric restriction and anorexia, thiazolidinediones (PPAR-γ inhibitor), and glucocorticoids, promote MAT accumulation [4].