Insulin

Insulin is a hormone produced by the beta cells of the pancreas, whose main function is to regulate blood sugar. When you eat - especially carbohydrates, but also protein - blood sugar rises and the pancreas releases insulin. Insulin acts like a key that opens cell doors for glucose: it directs sugar from the blood into muscle, fat, and liver cells for use or storage.

Insulin is not a 'fattening hormone,' although it's often called that. It is a normal and essential part of metabolism. Weight gain is always caused by an energy surplus, not insulin itself. However, insulin participates in energy storage, and at high concentrations it prevents fat burning - which is why constant snacking keeps the body in storage mode.

Insulin resistance is a condition where cells respond poorly to insulin. The pancreas must produce increasingly more insulin to achieve the same effect, which strains the pancreas and ultimately leads to type 2 diabetes. Insulin resistance affects an estimated 20-25% of adults, and it's particularly linked to abdominal obesity. The good news: insulin resistance is a reversible condition.

The most effective ways to improve insulin sensitivity are: exercise (especially strength training, which increases muscle glucose uptake), weight loss (just 5% is enough), sufficient sleep (7-9 hours), dietary fiber, and reducing processed foods. Intermittent fasting may also improve insulin sensitivity in some individuals. Insulin is closely related to carbohydrates, ketosis, and metabolic syndrome concepts.

Last updated: March 30, 2026