We buy 36 bottles of follow-on milk per week because DS receives most of his nutrition at night. I flipping well hate it but the Paediatrician told us that because he is autistic he would starve if we don't give him the food he wants when he wants it unlike other children. It's something to do with phobias and also hungry signals which don't get through.
We have seen this to be true and he lost a shocking amount of weight when we tried to stop it, plus he was up all night and all day and it nearly killed the whole family.
HOWEVER I didn't use it for my DD. Cows milk from six months (old guidelines) and she got her iron and protein from meat, fish, eggs, cheese and pulses whereas DS doesn't.
I could give him cows milk during the night but we can take the little bottles up with us, open them and blearily tip them into a vessel without properly waking up ourselves. I was told I should do the same with cheaper UHT cartons but you need scissors and greater coordination than either DH or I have with a child who wakes every two to three hours.
I especially hate being in this position because I am still BF DS a bit, I did it exclusively until he was 12 months old and feel a bit 
about Aptamil's advertising policy although I do see a need for formula (DD thrived on it)
But that's parenthood. You have to bend over and remove your Judgy Pants for a spanking on a regular basis 