Can you train a dog to become a picky eater?

Many if not all dogs will gobble food down as soon as it is presented to them. Can you train them to become more choosy?

Suppose you regularly set 10 plates of food in front of a dog, well more than the dog can gobble down in a minute or two. Will the dog learn to pick its favorites rather than just what’s closest?

How about if the dog has to press a lever to get food. There are several choices. All levers dispense food. The choices do not change, and every effort is made to demonstrate to the dog which lever dispenses which food. Perhaps a small sample is provided. Once one lever is pressed, all others are locked out. Will the dog start making choices based on preference?

It appears that dogs do have somewhat specific food preferences when given a choice.

I had a Rat Terrier who would eat nothing but old Roy ( Wal-Mart brand) dog food. She lived into her 20s. By that time her teeth were mostly gone. I had to soak it in milk for her to eat. She would not eat ANY canned food or people food, except bacon occasionally. She created her own preference.