I buy a high quality food, so I haven't been adding much. I give a fish oil tab once a day because both dogs have had dandruff and the vet said the oil would help keep skin moist and coat shiny. When they get really gassy I give plain yogurt.
I do let then have the healthy leftovers here and there, though. Green beans, chicken, beef etc that the family hasn't eaten by the next day. Usually we don't have leftovers or have very little.
Rita is on her 2nd round of prednisone for her ears. Shes been eating a lot more than normal!