Offer the gruel three to four times a day gradually reducing the amount of milk replacee used to make the gruel. This way your puppy gradually learns to adapt to solid food and gastric upset is minimized. By around eight weeks of age your puppy should be eating solid food. How often to feed your pup. Puppies should be fed three to four times a day therefore if you are currently feeding ¾ a cup of puppy food twice a day you should consider spacing it out by feeding ½ cup three times a day.