I recommend fixed feeding times. We also had a boy (a very thin one, Filou) who walked all over you when he wanted breakfast (at 3am) but he did that mainly with my husband who got up. When he was alone with me I pretended to sleep (you really have to do that convincingly) and in the second night he usually let me sleep.
With our next generation we did not feed them during the night from the beginning and they learned well