you need carbs sugars and fats to survive.
the pyramid isnt about serving size, its about having everything.
I understand this more than most. I changed my diet 3-4 months ago, eating more fruits for natural sugars, certain portions of meat that aren't too fatty, and limiting carb intake. The reason I'm limiting my carb intake is so that I could lose weight (which I've lost 80lbs after 3-4 months of just eating healthy). The high amounts of refined sugars, excessive amounts of grease, and large portions of carbs people do eat on a daily basis is not healthy. A single slice of pizza may not be horrible once in a while, but you can't expect to eat it once a day, every day, and expect to be healthy without cutting other things out of your diet to compensate. I'm sure some pizza is made healthier than others as well, but if pizza was healthy I'd be able too eat it to lose weight.