Diabetes mellitus (DM) is one of the oldest diseases, first described by the ancients Egyptians 3000 years ago (Ahmed, 2002). It is a chronic metabolic disorder that results from dysfunction of pancreatic β-cells and progressive failure of insulin secretion superimposed on insulin resistance (Mark et al., 2003) (Fig. 1). Insulin resistance is a condition of reduced responsiveness of insulin-target tissues to normal circulating levels of insulin in blood. The degree to which glucose tolerance in insulin-resistant individuals is affected mainly depends on function of both the magnitude of insulin resistance and the capacity of the pancreas to adequately cope with this defect (Spellman, 2010). The key causes of diabetes are thought to be genetic, weight gain by overeating and physical inactivity. Overeating causes excessive insulin secretion, which negatively affects the insulin secretory capacity from pancreatic β-cells, leading to obesity and insulin resistance (Muoio et al., 2008).