GCG and type 2 diabetes mellitus: The obese environment is highly complex and comprises changes in serum levels of multiple circulating factors such as glucose, leptin, glucagon, adiponectin, glucagon-like-peptide-1, insulin, free fatty acids (FFA) and cholesterol; altered sleeping behavior; altered gut microbiome; altered pharmacodynamics of therapeutics, poor wound healing and post-operative infections, and the development of comorbid diseases (including chronic low-grade inflammation, heart disease, type 2 diabetes and hypertension).