I have a friend here in town who has this massive American Pit that looks like he could devour an entire bag of Pedigree in 4 gulps. It is quite humorous to see how fickle he is about what he will eat. His owner put the food out at the same time each day and tried using various methods to get it to eat that he read about on the internet such as taking the food away after a certain amount of time. The dog would eventually eat but it just seemed like a rather joyless process for him. He also didn't like "Sweeties" (the name his owner has for treats) and would pop them in his mouth, and then drop them on the ground at which point one of his huskies would come by and gobble it up.
It's amazing to me that this animal maintains his massive size given how completely turned off by food it tends to be.