[hnick]

A rule of thumb we were taught is half the food comes from training (not to the point of cruelty, adjust the training to be easier if needed so they get enough). You can adjust per dog, but many people treat training rewards as "treats" which are surplus to their needs, so greedy or food-loving dogs (I would be one, as is our first dog) will take it but others won't care.

High stress or emotional arousal or a distracting environment will supersede this but it's a decent starting point which people often miss. Luckily our second dog likes play and praise so that gives us more options.

[SkyPuncher]

We used that for dog #1. Works great to be able to dole out kibble for training.

Dog #2 just doesn't care. She eats the recommended daily amount, but will take hours to finish a meal. Walking away and coming back later. She just doesn't care about food.

[hnick]

Yeah they really do vary a lot. Something I did not appreciate until getting my first as an adult (as a child, I had no positive feelings towards dogs which I find sad now).

I have heard trainers who suggest meal time is meal time, the food is taken if it is not eaten, it's not a self-serve grazing buffet. I think part of it is about making it clear who is in charge, especially if a dog is not listening during training, but there are other reasons I forget like resource guarding and predictable toileting. But we all decide how much we let them express their personalities :)