I do believe it will happen naturally in most cases. They just have different needs. Jack could go all night without a feed from early on, but even now doesn't eat much. Tom on the other hand needed the night feed until he was a year old, he just couldn't get through the night without it (not often anyway, there was the odd night!). And even now he is a big eater - during the day he can barely last between meals - he just needs to eat often (as do I btw, here I am eating lunch at 11am bcos I just can't wait any longer LOL). It's just their make up. "Training" them to not have the feed might work in the short term, but I suspect that down the track it can potentially cause other issues. My advice is to stick with the demand feeding while it is working for you. If you get too exhausted down the track you can look at other options then.