Glucose is the human body's key source of energy as it provides energy to all the cells in our body. Glucose also is critical in the production of proteins, lipid metabolism and is a precursor for vitamin C production.Glucose is the sole source of fuel to create energy for all brain and red blood cells. The availability of glucose influences many psychological processes. When glucose levels are low, psychological processes requiring mental effort l(self-control, critical thinking and decision-making) become impaired.