Why do dogs protect food

It is the nature of dogs to protect food to survive in the wild, but now as pets dogs are trained not to protect food. Some dogs used to live in poor conditions and need to plunder to eat food, so they will appear to protect food, this generally let the dog realize that no one will grab food with it, and slowly will improve. The owner can give the dog a meal of food in several portions. After it has eaten the first portion of food, the owner will give it a second portion. When it gets used to it from eating the first portion of food to add when eating. Then slowly change to picking up the bowl and adding it while eating. If the action of protecting food return to the previous step, the main purpose is to let it understand that the master will not snatch his food but will let increase food.