Normal blood sugar ranges between 60 to 100 milligrams per deciliter, according to the Diabetes Teaching Center at the University of California, San Francisco. This range is for a nondiabetic person testing between meals or first thing in the morning prior to eating.
After eating, a nondiabetic person's blood sugar should not exceed 140 milligrams per deciliter. Insulin is a pancreas-produced hormone that allows sugar to enter body cells, according to WebMD. It is then used as energy. Insulin also helps the body to store muscle, fat and liver cells. Those who are unable to properly produce insulin become diabetic and must either closely monitor their insulin levels or begin insulin injections.