Use a good dog food. Many have fillers which do nothing but add on calories. Although I do not use it, my vet always recommends Science Diet (there is one for dogs who need to watch their weight). Only feed what is recommended.
Do NOT overfeed. It helps to give food 3-4 times a day, instead of 1 or 2. (Just read what the daily recommendation is and split it 3-4 times). Your dog doesn't get as hungry.
Also, no snacks!!!! We cut out the snacks when Shelby needed to loose weight and it helped tremendously.
EXERCISE!!!! It really does help.... every bit counts!! We like to play ball in the hallway when we can't go outside to play.
Shelby & Seymour are both Teapots, too. But I still think it is important to keep them fit and healthy. I don't think it is a good idea to have a malnourished Yorkie (by underfeeding them) just cause they are a little on the bigger size. That would be cruel!
Good Luck on keeping your Teapot happy & healthy!!!