I know that adding baby rice to bottles is bad/not recommended, but I need some hard facts to back that up. My DH's brother's baby is 4 weeks old. She was low birthweight and has been ff from birth (mother chose not to bf at all). A week ago, they visited my in laws and the baby was screaming to be fed. Her mother said she was always wanting feeding, so my father in law (former cosmetic surgeon in his seventies) told her to thicken the milk. She said she didn't think it was 'allowed', but he assured her it would do no harm. So she's started adding baby rice to the baby's bottles of hungry baby formula. My MIL told me gleefully that baby has now started sleeping through .
My DH won't back me up that it's a bad idea because his Dad said it was ok and he's a doctor. I don't have contact with the parents directly, but if I can give some convincing evidence to MIL that thickening the milk is not in baby's best interest might get passed on by her.