High levels of the hormone insulin is a core problem for most people with obesity, as well as type 2 diabetes and high blood pressure. So how can it be treated?
Here's a good new review paper on it, from Professor Grant Scofield and co-authors. In short the effective treatments come down to carbohydrate restriction (including fasting) and high-intensity exercise.
Diabesity: Hyperinsulinemia: Best Management Practice