Insulin is a hormone secreted by the pancreas. Its main role is to allow sugar (glucose) from the food we eat into the cells so that it can be used for energy. Although insulin is mostly implicated in blood sugar management, it also affects fat and protein metabolism.
When we eat a meal that contains carbohydrates, the amount of blood sugar in the bloodstream increases. This is sensed by the cells in the pancreas, which then release insulin into the blood. Then insulin travels around the bloodstream, telling the body’s cells that they should pick up sugar from the blood.
This leads to reduced amounts of sugar in the blood, and puts it where it is intended to go, into the cells for use or storage. This is important, because high amounts of sugar in the blood can have toxic effects, causing severe harm and potentially leading to death if untreated. However, sometimes the cells stop responding to the insulin like they are supposed to. In other words, they become “resistant” to the insulin.
When this happens, the pancreas start producing even more insulin to bring the blood sugar levels down. This leads to high insulin levels in the blood. This may continue to develop for a long time. The cells become increasingly more insulin resistant, and both insulin and blood sugar levels go up.
Eventually, the pancreas may not be able to keep up anymore and the cells in the pancreas may become damaged. This leads to decreased insulin production, so now there are low amounts of insulin and cells that don’t respond to the little insulin that is available. This can lead to skyrocketing blood sugar levels.
When blood sugar levels exceed a certain threshold, a diagnosis of type 2 diabetes is made. In fact, this is a simplified version of how type 2 diabetes develops.
Dr. Robert Lustig, Professor of Pediatric Endocrinology at the University of California, San Francisco (USCF) reports that while the general consensus has always been that insulin resistance is the result of weight gain, recent data shows that insulin is what drives the weight gain. Insulin resistance is a component of multiple illnesses, including diabetes, fatty liver, arteriosclerosis, hypertension, and elevated triglycerides.