WHY do they say not to give babies rice cereal until 4-6 months, these days?

I realize that has fallen out of favor with pediatricians recently, the practice of putting cereal in a baby's bottle at a young age to supposedly fill them up more and get them to sleep longer, etc. But you'll still hear so many stories of people doing it, "with no problem," "and it helps... show more I realize that has fallen out of favor with pediatricians recently, the practice of putting cereal in a baby's bottle at a young age to supposedly fill them up more and get them to sleep longer, etc. But you'll still hear so many stories of people doing it, "with no problem," "and it helps her sleep through the night," all that.

So WHY exactly is it frowned upon? What would be bad about it? Why do you hear of so many people doing it with no issues whatsoever? What's the big deal? I'm just confused.
15 answers 15