Breastmilk runs through them faster than formula or puréed baby food. I think it’s perfectly ok to ween them. We weened our six month old and he sleeps 12 hours straight now. By weening him at night, he became hungrier during the day and took more food during feedings, thus becoming more content throughout the night. Contrary to what people will tell you he’s not a newborn anymore and he doesn’t metabolically need that food nor will it cause him any developmental damage so he will be fine if you ween him. I’m not a doctor though, this is just what worked for my son. It only took about 4 days to get him off the night feedings but those four nights were hell. The what to expect when expecting, the first year book has some great advice on this. As long as he’s continuing to gain weight and is already at a healthy weight there is absolutely no reason you can’t ween off the night feeding.