Yeah, Reggio... that's exactly the adage I live by when it comes to meal time.
Public health did a campaign a while ago that said; "It is the parent/caregivers job to decide WHAT to serve and WHEN to serve it. It is the child's job to decide IF they will eat it, and HOW MUCH they will eat."
Sometimes picky eating is just that, picky-ness. Other times it becomes a big power struggle. Like anything; consistent expectations and guidelines are the best in that case!