I do not believe your dog will eat your dead body if you die alone with him. First of all, if you were to die alone with your dog, your dog would probably try to save you or protect you in some way. Hopefully your body would be discovered in time for your dog to survive without being fed or given water.
Even without food or water, I think your dog would die before eating your body. I cannot imagine a dog eating your dead body unless he was extremely desparate for food.