There is such a lot of conflicting advice, and generally speaking, dogs are omnivores as in they will choose to also eat other things 'in the wild', of course we don't have much of a comparison these days, as dogs have been domesticated for so many years they are not the same as their still wild counterparts, although there are still similarities. It is true that a diet of pure protein is not good for them, but I like to see good quality meat in there at the very least, which precludes any meat meal for me. In fact I've just been prepping some chicken stock I cooked yesterday, I used some of the liquor in last night's tea, the rest will go in the freezer, but all the bits of left over meat, fat and gristle will go in the dog food bowls, along with the celery and carrot I put in there for flavour. The bones and onions will go in the bin. A lot of the problem with some of the grain free foods is that they jumped on the back of a fashionable bandwagon and claimed their foods were superior because they didn't contain a lot of wheat or maize (which has been the cause of a lot of allergies in dogs) but they replaced it with other products, most notably pea proteins that has been linked to some cases of myelopathy in dogs. Also remember that plants have protein in them as well, so it's not just a case of how much protein but different types of protein when looking through ingredients. My lot have done well over the years on the mixture of raw and dog foods I give them, at the minute I've got my old FCR who will be 11 next month, a good age for the breed, and my oldest two I lost over lockdown and just recently were both 14 1/2 and 15 1/2 respectively, and fit and healthy for most of their lives, with only Indie having cruciate problems that weren't related to diet. In the bad old days when dog food didn't exist dogs just ate what was left, which probably included the dreaded cooked bones along with a load of other stuff we'd never give our dogs these days. That said, mine get any appropriate left overs rather than put it in the bin, very little goes to waste, if i can't eat it, then there's either the chickens or dogs that can help out.