from Sabine "1. Free feeding only works with kibble, which is simply the least ideal type of food to feed, due to its highly processed nature.
2. Very few dogs actually self-regulate well enough to just eat enough to maintain a healthy weight. Sure, such individuals do exist (I've had one of my own), but they are very rare exceptions. Also, see #1.
3. If you don't feed scheduled meals, it's much harder to realize when an animal is off their feed due to stress, discomfort, pain, illness.
4. In our times, with many dogs being couch potatoes and not even getting the mental stimulation of regular walks (let alone more vigorous exercise, like performing in dog sports or doing actual work), meal times are a major highlight of their day, something they very much look forward to. Why take away one more of the few major stimulants?
5. House training. If you control when food goes into your dog, you can reasonably predict when it's going to come out the other end. Not so with free feeding.
And 6. which I throw in...The biggest thing with free feeding is that your dog is not as motivated for food rewards when training. Nearly all trainers want you to bring your dog in HUNGRY when coming in for classes. It's the number one motivator with dogs,some definitely more than others. Kibble is the least motivating generally. And depending on the type of training situations ,it's better to use something more enticing than kibble."