J.R.
The stomach lining is not fully developed until 6 months. That is why food allergies run high when a child starts solids early.
My 1st was FF and we started him on soilds a few days after he passed the 6 month old mark and we started we vegetables. Fruits are sweet and we did not want him to perfer the fruits over the vegetables.
My 2nd is still breastfed and we delayed solids till he was almost 9 months. We started the same way as with my oldest vegetables over fruit. I skipped cereal with him all together.
What I have noticed is that my oldest is a very picky eater and my youngest will eat anything you offer him. A few other mothers that I know who have delayed solids also noticed their LO will eat anything offered.
As per my son's dr she said to start solids @ 6 months and not before. She is also pro breastfeeding so she was ok with the delaying of solids as long as he was on them by 9 months.