During their first year, Newfoundlands grow from about a pound to over a hundred pounds. They require plenty of food to support such rapid growth. Once they reach adulthood, however, they have a very low metabolism, and Newfie owners find that their dog food bills are lower than those of friends with Labs or Shepherds. Overfeeding a Newf puppy, in the hopes of growing a bigger dog, can cause serious orthopedic problems. Remember, a lean Newfoundland is a healthy Newfoundland.