In particular, fruits and vegetables are low-calorie, low-fat, high-sateity foods.
You must be thinking of a different kind of fruit than I am. I could easily get half my daily calories from apples and oranges. Not to mention bananas or watermelons, which are basically fruit-shaped sugar water. I have to stop myself from doing it, like with chocolate or ice cream.
I recently came out against paleo in the open thread, and realized that I probably haven't yet heard the strongest arguments in favor of a paleo diet. So, what are said arguments?
EDIT: Or more generally, why should I eat less carbohydrates and more protein / fat?