Obesity and type 2 diabetes have become global issues through increased fat accumulation in adipose tissue due to a combination of chronic high calorie food intake and sedentary lifestyle. Interestingly, results presented in this thesis reveal that depletion of myostatin (Mstn), a TGF-β superfamily member, leads to reduced fat accumulation and improved insulin sensitivity in mice even during diet-induced obesity. This thesis includes a general review of literature (Chapter 1), a detailed materials and methods chapter (Chapter 2), followed by 4 results chapters, focusing on delineating the mechanism of how Mstn regulates carbohydrate metabolism (Chapter 3) and lipid metabolism (Chapter 4). Moreover, global gene expression analysis was undertaken to determine the molecular function of Mstn in metabolism (Chapter 5). In addition, there is one chapter discussing a novel role of Mstn in skin regeneration (Chapter 6). Finally, the thesis ends with a prospective chapter (Chapter 7).