Is it common practice to "starve" a horse, so that it is easier to control?

I was shocked at a farm i visited, i was looking to buy a horse and found a couple farms will not have a horse in "condition" and an owner told me she doesn't like a Healthy looking horse, they tend to misbehave. Is there any nice looking, manageable horses out there, that have that sweeting loving personality that is "fit as a horse?"