My lo is a piggy, however, to get him to take more and to attempt to stop snacking with all of my kids, I either took them down from 3 hours between to 2 1/2 and did that all day, waking them if I had to, and then extending them and trying to get more in each feed, or stretching them out and trying to get more in at each feed. I have also been known to give water at night (no calories) when attempting to do this. Liam has been doing BW since day 1, so we haven't really had to do this, but I did with the other 2. Callum was a big time snacker - every hour and a half, just about killed me- and he is still a snacker at 4 and a half.
Don't know if this is helpful.
Lisa