Glucose is one of three energy sources that human body ingests and processes to obtain energy. The body harvests energy and produces carbon dioxide as an end product. An observation was made by ancient Indian doctors that urine from patients contains sweet odor. This observation was made in 400B.C. this was the first time people noticed the relevance between obesity and energy wasting disease. Another significant characteristic established was that these patients could be divided into two groups: the first group of patients shares common syndromes of emaciated, dehydrated, diurea and fatigue. The second group is heavy in body weight, eating excessively. Until 1 B.C. this disease was named “diabetes mellitus” which means consuming sugar. In 1923, Scottish biochemist John Macleod who once worked at Western Reverse University together with a Canadian physician Frederick Banting was co-awarded the Nobel Prize in Physiology or Medicine for the discovery of insulin. They found out how the extract of a pancreas can somehow lower blood glucose level in diabetic dogs at first. Then protein known as insulin was purified from the pancreas extract and injected into a diabetic patient in Toronto. The patient’s condition improved significantly and this successful event set a milestone for treatments of diabetes.