The following is an excerpt from Petfinder.com’s The Adopted Dog Bible
Most experts recommend feeding your dog twice a day — once in the morning and once in the evening — though puppies under five months of age should be fed three to four times a day, or as directed by your veterinarian.
While most dogs will dig in the moment you place the bowl on the floor, you may find that your adopted dog is a finicky eater, at least at first. After all, he’s been thrust into a new home with new people, and he may be too nervous to eat. If this is the case, you will need to teach him to eat on a schedule.
Leave the bowl on the floor for ten minutes and then pick it up, regardless of whether he has eaten. (If your dog is a slow eater, this period can be extended to twenty minutes, but only if he is still eating during that time and hasn’t gone off in search of other entertainment.)
At the next scheduled feeding time, put the bowl back down, again for only ten minutes. Pretty soon your dog will learn that he needs to eat when the food is offered.
Having regularly-scheduled feeding times not only establishes a routine, it also allows you to monitor your dog’s health. If he picks at his food throughout the day, you may not notice right away if he’s not eating well. But if he normally eats heartily as soon as you put the bowl down, you will immediately see a sudden lack of appetite, which is often an indication that he’s not feeling well. If your dog’s appetite doesn’t improve in a few days, have him checked by your veterinarian.
Another benefit of set feedings is that a dog who eats on a schedule poops on a schedule. In addition, if you live in an urban area, leaving a bowl of kibble on the ground all day can attract unwanted house guests, like cockroaches and mice. It is to everyone’s advantage to keep feeding times regular.