Type 2 diabetes mellitus is the most widespread form of the disease. It most often strikes those over 20 years of age. The pancreas is still functional, but the cells of the tissues and muscles become unresponsive or the pancreas can no longer manufacture enough insulin. Obesity greatly increases the risk of developing type 2 diabetes, but the exact cause is unclear. Most type 2 diabetics are overweight, but some are able to regulate it through improved diet, oral meds and physical activity.