Picky eating in young children can have many causes. Although usually it just represents normal child behavior, at times it may be a sign of a serious underlying
illness. The physician best capable of helping you with this problem is your
pediatrician.
The first step in evaluating picky eating is to be certain that your child is growing well. Your pediatrician's office can review his growth curves to determine this. Assuming he is growing well, the source of his picky eating is most likely behavioral.
A common strategy used by pediatricians to encourage children to eat is to limit juices, liquids, and snack foods between meals. Often children fill up on liquids or small snacks and therefore are not hungry for family meals. Your pediatrican may advise you to limit 'grazing behavior' between meals.
Young children often prefer less nutritious foods. Your pediatrician may advise you to continue offering nutritious foods to your child in a persistent by non-antagonistic way. Other creative strategies might include 'hiding' nutritious foods inside your child's favorite, less-nutritious foods. Finally, your pediatrician might advise you to provide your child with a daily multivitamin preparation to compensate for nutrients not consumed in food.
As always, formal treatment and advice for this problem will depend on a personal examination by your child's pediatrician.