Mine is breast fed, apart from bottle at 10pm and 10am of formula. She has in the past done longer spells at night, feeding at 10 then not again till 4.
Now she's reverted to feeding at 10, 1 and 4 
I'm not doing anything differently! And she wakes up hungry at 7 so it seems like she is genuinely hungry at night. But I think there's an element of comfort too though as she doesn't feed for long in the night.
I'm wondering if perhaps my supply isn't good enough now she's bigger, or if she's having a growth spurt. Would love go hear about your 4 month olds/thoughts!