Stubborn dog

Question
Hello!
I have a 2 and a half year old bullmastiff and he's a very stubborn eater. He loves our food more than his and he will only eat his food when he knows he wont get any from my family ie; if no one is home. Recently, my dad began to cut up into very small pieces leftover meat such as chicken or steak, that he puts into his food. This way, he will eat all of his food at one time rather than waiting for hours to do so. I don't think this can be harmful to him but I thought it was best to ask an expert.

Answer
Adding a little bit of meat like that won't itself hurt the dog.  Having to do so suggests the dog is overweight which is very harmful.  Your dog definitely should be narrower at the waist than the hips and chest. You should be able to easily feel the ribs, but not see them. Each dog is different. Standard recommendations are a good place to start, but each dog must have its food and exercise adjusted to its individual needs. Here is a link to a good illustrated guide, http://www.longliveyourdog.com/twoplus/RateYourDog.aspx