Some families treat a shared meal as a pleasure, both because it is a sociable occasion and because they like eating. The children generally enjoy their food, but if on a particular occasion they do not feel like eating what is offered, they are free to leave it, and it is no big deal. They are not pleaded with, cajoled or ordered to eat: eating is a normal response to their own hunger, and not something done to please others.
Others (or "every parent", as Kathy Harvey would have it) treat eating as an unfortunate necessity, to be foisted on unwilling children by stealth (eg toddlers fed amidst a circus parade of distracting toys), threats or bribery. The children, understandably, come to view everything put on their plate with deep suspicion, and to take a certain pleasure in the ritual games played out each time they push it away.
Parents need to realise that they are free to choose which group they join.