Milk!

Personally I’d try 5 for a day or two and drop back down if he’s still not having. It’s expensive for sure but better a full baby than a hungry one. We’ve figured that now my 10wk old is sleeping 7-8 hours at night we give him 7oz for his first and last and 6oz the rest of the day. I upped him from 6 to 7 all day but it was being wasted so just doing what works day by day🥰

Do the 5, they’ll chop and change going through growth spurts. My girls up to 7 now at 8 weeks and sometimes doesn’t finish it but I upped it as most of the time she does. Don’t know where she puts it but she’s always had a bigger appetite. Feed on demand if he wants it he’ll have it if not no biggie. They also drink more sometimes to make up for sleeping longer at night x

Do 5 😊 even if he leaves half oz or 1oz

switch to 5 and leave it a bit longer between feeds. My daugjter is 8 weeks and having mostly 6oz she used to waist bits when first changed but now its rare she wastes any.. just make sure they are actually hingrybwhen you feed them x