My dog is almost two. She decided one day when she was about 6 months old that she was going to be a free feeder. Was such a quick change. One day, she is excited as could be to get food and scarf it all down. The next, she'd only eat about half of her helping and then the rest later in the day. As I type this, I hear her eating a bit now.
It wasn't a huge deal since my previous dogs had been free feeders. I wasn't planning to do that with her, but it works.