I agree that breastfeeding can probably be healthy for your child forever. Not arguing that point. In fact, almost everything I found online says that breastfeeding should continue until you and the child decide to stop. But when does it "cross the line"? I never breastfed, wasn't able to. I tried, though. But I couldn't have seen myself breastfeeding my son past 1 year, MAYBE 18 months. It's incredibly inconvenient. And after a certain age, the nutritional benefits do decrease, as njqt466 said. What five year old wants to tell his friends that when he gets home from school, he's going to snack on cookies and boob? Seriously. My son was strictly formula fed. Started on cereal when he was 4 months, baby food at 5 or 6 months, and some normal "adult" foods (i.e., hotdogs, dry cereal) at 9 months. He's incredibly intelligent, fully functional, independent, and has no health problems at all. Not even seasonal allergies. So I guess formula can't be all bad. I do make an exception for people in 3rd world countries who don't have milk or formula or whatever other items their child would need to have a healthy, balanced diet. That comes out of necessity. But here in America, I think it comes out of want/need/insecurity on the parents behalf.