Eating to Improve Equine Insulin Sensitivity

Do you have an overweight horse? Chances are he is insulin resistant. Excess body fat leads to elevated insulin. Elevated insulin leads to more body fat storage which leads to greater insulin resistance and the vicious cycle continues. Even horses of normal weight can be insulin resistant exhibited by regional fat deposits along the neck shoulders tailhead and back. 
The opposite of insulin resistance is insulin sensitivity.
Unlike when humans are sensitive to a food or ingredient meaning intolerant or allergic insulin sensitivity is a good thing. It simply means that the horses cells respond well to insulin and there is no longer a need for the pancreas to continually pump out high levels of this hormone. Storage of body fat normalizes as well as blood sugar levels. 

Putting your horse on a diet that restricts forage will not increase insulin sensitivity. The problem is that horses are designed to graze. They need to consistently chew to neutralize stomach acid through saliva production a natural antacid. Left with an empty stomach your horse will likely develop ulcerations but even more damaging is the hormonal stress response he will experience. This results in increased insulin and ironically your horse remains overweight because excess insulin tells the body to hold on to body fat. Furthermore insulin is highly inflammatory leading to pain and inflammation throughout the body including increasing the propensity for developing laminitis.
Reduce concentrates but not forage.
Calorie reduction though important should only be accomplished by reducing or even eliminating commercial feeds and