The only limit to what you want on a pizza is what you are will ing to spend. The more you put on top, though, the more difficult it becomes to cook it properly. The bottom will be done to the point of being cardboard, while the top of the dough is still not cooked and is gooey dough. Yes, you can count veggies on a pizza os one serving towards your daily five servings of vegetable goals. But the rest of your pizza counts as three days of calories, carbohydrates, and dairy.