Acclimate your puppy to having his/her food and possessions touched by humans. You need to teach the puppy that you are not going to take away the food and not give it back. Handle the food bowl while your puppy eats, pet your puppy and every now and then lift the bowl, place in a special treat, and return it. This way the puppy learns to tolerate intrusions and disturbance while it eats and will not be startled and react aggressively should something unexpected happen while eating. Also, when giving food make sure to have the puppy sit and stay, then put the food in the appropriate place, and once food is in its place then tell the puppy it’s ok. This will tell your puppy that you are the alpha (leader) and you are in control.