When my older son was a baby, we were told to start him on rice cereal at about 3 weeks old. He was on juice too. Baby food started a couple of week after that. We started him on milk at about 6 mos. old. Also, our pediatrician told us to give him an ounce or so of water throughout the day.

By the time our next son was born 8 years later, this had all changed. No milk until after 1, no cereal until 6 months. No water

Both of our sons played sports and both are in good physical shape today at 46 and 38.