In a healthy body, the pancreas synthesizes, stores, and releases two hormones, insulin and glucagon, to regulate the body's blood glucose levels.
Insulin is considered to be the hormone of the fed state because it stimulates cells to take in glucose. After eating a meal, glucose spikes and insulin levels rise in order to bring the blood glucose level back to the normal range of 70-100mg/dL, which is the normal range after 8 hours of fasting. Insulin is constantly secreted, more after eating, and at a much lower rate if the glucose levels are low.
Glucagon, on the other hand, helps the body raise blood glucose levels when they are low, such as between meal times. It stimulates mobilization of amino acids and fats, gluconeogenesis, and the release of stored glucose (glyconeogenolysis) by the liver.