It sounds like you aren't hungry, but "snacking" is just one of the things you do in the evening.
You need to change your routines.
Clean your teeth when the DCs go to bed, it does help lose the desire to snack.
Get some books you want to read, if need be, go to bed with a book when the DCs are down, rather than sit on the sofa watching TV/MNing, so you have moved from the normal routine, which will be 'missing' the snacks.
If you have DH at home too, can you plan more evening things to do, once DCs are down? Go out to see friends (not with food!), go for a walk/run/exercise class. Join book clubs or evening classes.
You need to break the habits and the routine.
It doesn't matter how great you low carb or any other diet you follow, you will want snacks in the evening if "sit on the sofa with a snack" is what you do in the evening, regardless of hunger levels.
Change the routine around food, break the bad habit.