Used to find this before going Paleo. The answer for me was MOAR FAT at breakfast, along with the carbs and protein.
The other thing is that you might not actually be eating enough at meal times.
Example breakfasts that stop me from snacking:
scrambled eggs, palm sized portion of smoked salmon or bacon, 1/2 avocado
Berries topped with coconut milk/cream and toasted nuts and flax seeds with a drizzle of flax oil
Home made frittata using eggs, chopped veg, potato, some chorizo or bacon and cooked in butter or coconut oil (I make on a Sunday, lasts 4 breakfasts)
Breakfast sausage patties made with pork mince and diced veggies, usually have those with some spinach and tomatoes – I take them to work and heat them in the microwave
If you’re more a fan of sweet stuff at breakfast I also make Paleo pancakes using eggs, mashed banana and ground almonds which can be made in advance and heated in the toaster, then topped with whatever you want
I snack heaps less on Paleo, I am much, much less hungry between meals. I don’t need to count calories either and I can maintain my weight pretty well, in conjunction with regular exercise.