Insulin and glucagon are both hormones created in the pancreas and work together to balance your blood sugar levels that help fuel your body, keeping them in the narrow range that your body requires. These hormones are like the yin and yang of blood glucose maintenance.
Insulin and glucagon work in what’s called a negative feedback loop. During this process, one event triggers another, which triggers another, and so on, to keep your blood sugar levels balanced.
How insulin works
During digestion, foods that contain carbohydrates are converted into glucose. Most of this glucose is sent into your bloodstream, causing a rise in blood glucose levels. This increase in blood glucose signals your pancreas to produce insulin to stop blood sugar levels rising too high (causing hyperglycaemia).
The insulin tells cells throughout your body to take in glucose from your bloodstream. As the glucose moves into your cells, your blood glucose levels go down. Some cells use the glucose as energy. Other cells, such as in your liver and muscles, store any excess glucose as a substance called glycogen. Your body uses glycogen for fuel between meals.
How Glucagon works
Glucagon works along with the hormone insulin to control blood sugar levels. Glucagon is released to stop blood sugar levels dropping too low (hypoglycaemia),
The release of glucagon is stimulated by low blood glucose, protein-rich meals and adrenaline (another important hormone for combating low glucose). The release of glucagon is prevented by raised blood glucose and carbohydrate in meals, detected by cells in the pancreas.
In the longer-term, glucagon is crucial to the body’s response to lack of food. For example, it encourages the use of stored fat for energy in order to preserve the limited supply of glucose.
About four to six hours after you eat, the glucose levels in your blood decrease, triggering your pancreas to produce glucagon. This hormone signals your liver and muscle cells to change the stored glycogen back into glucose. These cells then release the glucose into your bloodstream so your other cells can use it for energy.
This whole feedback loop with insulin and glucagon is constantly in motion. It keeps your blood sugar levels from dipping too low, ensuring that your body has a steady supply of energy.
Fasting encourages the triggering of Glucagon, especially if you perform some cardio work requiring instant energy. Doing a workout first thing in the morning can encourage the pancreas to release Glucagon thereby creating energy from the fat stores. My personal trainer put me on to this fasted cardio routine of walking before eating and setting my body up burning fats first thing in the morning.