my advice: A big brekkie- like porridge (i usually put some fruit in mine) A medium lunch(i usually have a sandwich with tuna or chicken or turkey) A big early dinner_ i try to eat by 7 and have a lot of carbs with this- pasta or rice. Vegetable soup isn't dinner! You need some protein and something to fill you. My lowest calorie dinner is any veg in the fridge (tomatoes,peppers,onions,spinach,courgettes) with prawns and Dolmio Express Tomato and Basil Sauce with Pasta or rice.
I think because you had such a light dinner you craved snacks. Tamara has called me "the cookie monster" because i love my biccies but I do try to eat a full meal every evening to fill me up beforehand. If you eat what my mother would call "a good dinner" and your fruit puree as dessert (like I do) hopefully you won't get the munchies.
There's no science to this at all,(or if there is I don't know it ) its just what works for me.