Insulin is produced by special cells in the pancreas, a large organ located behind the stomach. Insulin helps the body use and store glucose (sugar), which is produced during the digestion of food. Insulin is secreted into the blood at each meal and allows the body to use glucose as energy to fuel basic daily functions like moving and breathing. The January 10, 2007, issue of JAMA includes an article about treatment of diabetes. This Patient Page is based on one previously published in the May 7, 2003, issue of JAMA.