I can only tell you of my old dog, years ago. She was a cocker cross and loved food, trouble was she lived in our family and we spoiled her by giving her table offerings too. She soon realized that our food was more tasty to her than boring old dog food. We then spent the rest of her life going from this food to that. The bottom line was if she didn't want it she's starve herself (3 days when we put our heels down and so did she). We thought fasting was bad for her and back to the cycle, we'd offer human food, she'd pig out, we'd offer dog food she'd stop eating. I've sat on the floor and fed this dog with a fork, one bite at a time. She died of kidney failure and I believe we were to blame. She is the only fussy dog we've had and I've toughened up a lot since then, more to prevent going through kidney failure again. Since her we have chosen a food, if weight is maintained and coat looks good, eyes bright then that's what they stay on whether they self fast or not. Never had a fussy dog since but loved them all just as much.