I have the same problem with my gelding. He looks well behaved in the pic to the left, but boy does he love to eat. I may have created the problem when on lead, only because I take him out to hand graze alot. I like when he can get some good green grass, especially at the end of the season when the grass isn't as plentiful in the pastures.
However, it has developed in to a problem when bridled. Sometimes I hate taking him out on a trail ride because I have to fight with him most of the way over the grass. It really gets annoying. I hate pulling back on the reins because I don't want to cause a hard mouth so I try to circle him only to get about another 10 feet before he traies again. Most of the time what is supposed to turn out to be a nice relaxing trail ride, turns into a work session and we usually don't get to go very far.