You would expect a starving dog to be more aggressive around food, however in your typical household this would never be the case. You may have a greedy dog or one that is ready for its dinner, but I have come to find that they learn they will be fed and there's plenty for everyone. Any special treats given or found are still to be given up or allowed to be touched by humans if needed, all mine will do so with a happily (they all have easy going temperaments though).