The constant hunger thing is a feature of insulin-resistant and leptin-resistant horses, but it does decrease as the diet gets tightened and balanced; exercise will also help reduce insulin levels. What I can't tell you is how long this will take, as each horse is different, and some stay as ever-hungry gannets forever. My crew took about 3 or 4 years of controlled feeding to lose that excessive hunger, but it did happen.
Jaini Clougher (BSc,BVSc)
Merlin (over the bridge) ,Maggie,Gypsy, Ranger