The thing to watch out for is not just the carbohydrates, but the carbohydrate load. A small banana occasionally for breakfast might be OK, a bit of cereal now and again might be alright, but banana, cereal and milk (which I presume is the low fat kind) is just too much carbohydrate load. All vegetables and fruit have some carbohydrates, not just potatoes etc. So if you go by say 15 carbs per meal you can choose what you want to eat, and how much. You then have to consider what you get more for your buck with. You may find you do alright on 20 carbs a meal or 30. It is all up to your body, what medications you are on, whether you need to lose weight or not, and how much carbs your body reacts to.