Providing your dog with the proper motivation is essential to any training program. Motivation means food, toys, games, play...anything that your dog will work for. In most cases food is the easiest and most motivating source of reinforcement. There is nothing wrong with using food to train your dog, but it must be used appropriately so that your dog obeys despite its abscence.
Some dog owners refuse to use food for a variety of reasons. They use force or just don't train their dog altogether. My answer to the food phobics is simple- would you go to work every day for free? No? Then you shouldn't expect your dog to either! If someone drove you to work, pushed you through the door and sat you down (however gently) would it make YOU want to work?! If every time you tried to leave they brought you back and sat you down again, day after day with no end in sight, no rewards, no promise of rewards...what would happen to you? Don't you think eventually you'd shut down and stop responding to the people around you?
Food is a primary need of all living things, no creature can exist without food, so what's wrong with using a basic need to motivate and train your dog?
There are several basic rules that should be followed when motivating your dog with food. Use food to introduce new behaviors and show your dog what to do. Once your dog knows what to do, hide the food and vary when you give it. For instance, when teaching the dog to sit, food is used initially to lure your dog without force into the desired position. Once the dog is sitting reliably, you replace the lure with a hand signal and vary when you give the reward.
Hiding the treat and varying when you give it is called variable reinforcement. This means that food is now hidden most of the time when asking for the behavior and is given sporadically, ie every other time, every 3rd time, etc. This keeps your dog guessing and makes his performance reliable and sharp every time you ask for it.
A real life example of variable reinforcement is a slot machine. People play the slots because every once in awhile they win! They can lose $150.00 in five minutes, but if they pull the handle and win just once the likelihood of them trying again is greater.