What is the time to start giving orange juice to a baby or toddler?

Why give it at all. I'm not a big supporter of juices. The kids get more nutrition from the orange wedges than they get from juice. The same goes for grape, apple etc. I'm afraid many of the adult obesity problems we see are related to a preoccupation with sweet things we train babies to want in infancy. Water is a great drink, fruits are a part of a great diet. Juices are basically baby colas.