ground beef (not lean) is great ... the fattier the food, the more weight your dog will gain .. but what everyone else has said is totally true ... is your dog actually looking skinny? can you easily make out ribs, spine and hips? on a healthy-weighted dog, you should be able to put your hands on the dogs ribs, and with gentle or little pressure, feel your dogs ribs ... for most breeds (not like saluki's and greyhounds and other sighthounds) you should not be able to clearly make out the hip points, ribs, and spine ... congrats on switching to raw!!! my dogs are SOOO much happier and healthier!