While other hormones play a role in metabolism, insulin is crucial for regulating blood glucose levels, promoting glucose uptake by cells, and stimulating the storage of energy reserves like glycogen and fat.

Here's why insulin is considered the major metabolic hormone:

* Blood Glucose Regulation: Insulin is the primary hormone responsible for lowering blood glucose levels. It does this by promoting glucose uptake by cells (especially muscle and fat cells) and inhibiting glucose production by the liver.

* Anabolic Effects: Insulin promotes the synthesis of proteins, fats, and glycogen, helping build and store energy reserves.

* Essential for Energy Utilization: Insulin is necessary for cells to use glucose for energy.

While other hormones like glucagon, cortisol, and growth hormone also impact metabolism, insulin holds a central and critical role in regulating these processes.