When I did CD (briefly) I always split my packs into 2 or 3 anyway, so i could sometimes have a tiny bit of one if I needed extra one day...
If you can manage without and just have an early night then you probably are best, but I personally don't think it's a good idea to let yourself get to the point where you are trying to get to sleep feeling absolutely starving... surely that's your body trying to tell you something!!