The digestive system can only access the exterior surface of a food particle. The chemicals down there are only so strong, and they aren’t going to just dissolve a food particle if it’s too big. If a baby doesn’t have molars yet and isn’t thoroughly chewing food (my 3 year old still doesn’t chew much before swallowing, as obviously evidenced when he throws up barely chewed food!), then much of what may still fit down the pipe will eventually just come out the other end without benefiting the body much along the way. This is very obvious from a cursory examination of diaper contents.

If you’re just feeding the baby certain solids for fun, then you may not care. But if you actually want the baby to extract significant nutritional benefit from what you’re feeding it, then I think it’s still a good idea to throwing it in the pureeing device of your choice to chop it up into as small particles as possible to compensate for the lack of chewing. I just don’t see how gums are capable of breaking down a lot of food types the way the body needs it broken down.

Other than that, the other biggest danger of this approach I see is using it in an environment where the rest of the family isn’t really eating as healthy as they should be. I would cringe in horror if I saw parents feeding their babies the kind of stuff most adults often eat. Their bodies are just not as capable of “tolerating” the kind of stuff that adults eat regularly. Obviously, however, the solution to that problem is not to prepare special healthier food for the baby but to change the whole family’s menu!