When blood sugar surges after a meal in those with insulin resistance, it is accompanied by a massive release of insulin. This insulin does eventually activate insulin receptors to open up cells to glucose, and this glucose surge is usually followed by a rapid drop in blood sugar. As blood sugar plummets, the brain, pancreas, and liver sense this rapid drop and an emergency is declared, since extremely low blood sugar is potentially deadly. To prevent severe low blood sugar (hypoglycemia), hormones such as glucagon, epinephrine (Adrenalin), and cortisol are released, all of which promote the release of stored glycogen from the liver and muscles, and result in the synthesis of glucose from dietary or body protein. As a result, those with insulin resistance will experience food cravings as their blood sugar begins to drop. In essence, the brain is alarmed by any rapid drop in blood sugar, so it does everything it can to get you to reach for a quick sugar fix.
It has been known since the 1950s that a sudden decrease in blood sugar over a short period of time is a primary trigger for food cravings and eating, if food is readily available. Several experiments on both animals and humans support this so called "glucostatic theory" of appetite control. Although we know that the control of appetite is influenced by a whole orchestra of hormones, peptides, and neurotransmitters, glucose can still be considered a lead player and perhaps the conductor of this orchestra. Currently, we at the Hunger Free Forever program know that rapid and deep drops in blood sugar are particularly associated with very strong, and in some cases irresistible, urges to eat.
Find out more about this book:Hunger Free Forever: The New Science of Appetite Control